苏坡特

判断合法 IP

Fri, 12 Aug 2022 23:22:43 +0800

题目描述：

现在IPV4下用一个32位无符号整数来表示，一般用点分方式来显示，点将IP地址分成4个部分，每个部分为8位，表示成一个无符号整数（因此不需要用正号出现），如10.137.17.1，是我们非常熟悉的IP地址，一个IP地址串中没有空格出现（因为要表示成一个32数字）。

现在需要你用程序来判断IP是否合法。

注意本题有多组样例输入。

输入描述：

输入一个ip地址，保证是xx.xx.xx.xx的形式（xx为整数）

输出描述：

返回判断的结果YES or NO

示例：

输入：

10.138.15.1
255.0.0.255
255.255.255.1000

输出：

YES
YES
NO

解题思路：

1、地址分四段，且必须有四段
2、dot 有三个，且必须三个
3、每段数字在 0 - 255 之间
4、每段数字长度大于 0，少于 3

测试用例：

10.128.1.156.1
10.128.1.
10.128.1.156.
256.0.0.0
10.1111.1.1
1..0.122
12.a.89.1
255.255.255.255
0.0.0.0

题解 - C 语言

int main()
{
    char ip[20];
    while (scanf("%s", ip) != EOF) {
        int len = strlen(ip);
        int seg = 0;
        int dot = 0;
        int seg_len = 0;
        for (int i=0; i<len; i++) {
            if (ip[i] >= '0' && ip[i] <= '9') {
                seg_len++;
                seg = seg*10 + ip[i]-'0';
            } else if (ip[i] == '.') {
                if (seg > 255 || seg_len == 0 || seg_len > 3 || (seg==0 && seg_len>1)) {
                    printf("NO");
                    break;
                }
                seg = 0;
                seg_len = 0;
                dot++;
            } else {
                printf("NO");
                break;
            }
        }
        if (seg > 255 || seg_len == 0 || seg_len > 3 || (seg==0 && seg_len>1)) {
            printf("NO");
            break;
        }
        if (dot == 3) {
            printf("YES");
        } else {
            printf("NO");
        }
    }
    return 0;
}

学生方阵

Tue, 19 Jul 2022 23:39:55 +0800

题目描述

学校组织活动，将学生排成一个矩形方阵。请在矩形方阵中找到最大的位置相连的男生数量。这个相连位置在一个直线上，方向可以是水平的、垂直的、呈对角线的或者反对角线的。注：学生个数不会超过10000.

输入描述:

输入的第一行为矩阵的行数和列数，接下来的n行为矩阵元素，元素间用“,”分隔。

输出描述:

输出一个整数，表示矩阵中最长的位置相连的男生个数。

示例1

输入
3,4
F,M,M,F
F,M,M,F
F,F,F,M

输出
3

测试用例

4,5
H,M,H,M,H
H,M,H,M,H
H,M,H,M,H
H,M,H,M,H
4

4,5
M,M,M,M,M
H,M,H,M,H
H,M,H,M,H
H,M,H,M,H
5

4,5
M,M,H,M,H
H,M,H,M,H
H,H,M,H,H
H,M,H,M,H
4

4,5
M,M,H,M,M
H,H,H,M,H
H,H,M,H,H
H,M,H,M,H
4

4,5
M,M,H,M,M
H,H,H,H,M
H,H,M,M,H
H,M,M,H,H
3

C语言题解：

todo
#include <stdio.h>
#include <stdbool.h>
#include <string.h>
#include <stdlib.h>
#define MAX 105
int n,m;
int g[MAX][MAX] = {0};
int main()
{
    scanf("%d,%d", &n, &m);//printf("%d %d\n", n, m);
    char s[500] = {0};
    for (int i=0; i<n; i++) {    
        scanf("%s", s);//printf("%s\n", s);
        for (int j=0; j<m; j++) {
            //printf("%c", s[j*2]);
            if (s[j*2] == 'M') {
                g[i][j] = 1;
            }
        }
    }

    int max = 0;
    for (int i=0; i<n; i++) { // 从左到右
        int k = 0;
        int cnt = 0;
        while (k<m) {
            //printf("%d ", g[i][k]);
            if (g[i][k] == 1) {
                cnt++;
                if (cnt > max) {
                    max = cnt;
                }
            } else {
                cnt = 0;
            }
            k++;
        }
    }

    for (int i=0; i<n; i++) { // 左上到右下
        int k = 0;
        int cnt = 0;
        int x = i;
        while (k<m && x<n) {//printf("%d ", g[x][k]);
            if (g[x][k] == 1) {
                cnt++;
                if (cnt > max) {
                    max = cnt;
                }
            } else {
                cnt = 0;
            }
            k++;
            x++;
        }
    }
    
    for (int j=0; j<m; j++) { // 从上到下
        int k = 0;
        int cnt = 0;
        while (k<n) {
            if (g[k][j] == 1) {
                cnt++;
                if (cnt > max) {
                    max = cnt;
                }
            } else {
                cnt = 0;
            }
            k++;
        }
    }
    for (int j=0; j<m; j++) { // 左上到右下
        int k = 0;
        int cnt = 0;
        int y = j;
        while (k<n && y<m) {
            if (g[k][y] == 1) {
                cnt++;
                if (cnt > max) {
                    max = cnt;
                }
            } else {
                cnt = 0;
            }
            k++;
            y++;
        }
    }
    for (int j=0; j<m; j++) { // 右上到左下
        int k = 0;
        int cnt = 0;
        int y = j;
        while (k<n && y>=0) {
            if (g[k][y] == 1) {
                cnt++;
                if (cnt > max) {
                    max = cnt;
                }
            } else {
                cnt = 0;
            }
            k++;
            y--;
        }
    }
    for (int i=0; i<n; i++) { // 右上到左下
        int k = m-1;
        int cnt = 0;
        int x = i;
        while (k>=0) {
            if (g[x][k] == 1) {
                cnt++;
                if (cnt > max) {
                    max = cnt;
                }
            } else {
                cnt = 0;
            }
            x++;
            k--;
        }
    }     
    printf("%d\n", max);
    return 0;
}

判断字符串子序列

Mon, 18 Jul 2022 20:43:12 +0800

题目描述

给定字符串 target和 source, 判断 target 是否为 source 的子序列。
你可以认为 target 和 source 中仅包含英文小写字母。
字符串 source可能会很长（长度 ~= 500,000），而 target 是个短字符串（长度 <=100）。
字符串的一个子序列是原始字符串删除一些（也可以不删除）字符而不改变剩余字符相对位置形成的新字符串。
（例如，“abc"是"aebycd"的一个子序列，而"ayb"不是）。
请找出最后一个子序列的起始位置。

输入描述:

第一行为target，短字符串（长度 <=100）
第二行为source，长字符串（长度 ~= 500,000）

输出描述:

最后一个子序列的起始位置，即最后一个子序列首字母的下标

示例1

输入
abc
abcaybec
输出
3

说明
这里有两个abc的子序列满足，取下标较大的，故返回3
备注:
若在source中找不到target，则输出-1

测试用例

abc
cabdef
-1

abc
afegbdefsec
0

abc
dfsabcdefahibjkic
9

C语言题解：

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#define MAX_SOURCE 600000
#define MAX_TARGET 110
int main()
{
    char target[105] = {0};
    char source[MAX_SOURCE] = {0};
    scanf("%s", target);
    scanf("%s", source);
    const int t_len = strlen(target);
    const int s_len = strlen(source);
    int i = t_len - 1;
    int j = s_len - 1;
    int idx = 0;
    while (i>=0 && j>=0) { // 从尾部到头部开始比较
        if (target[i] == source[j]) {
            if (i == 0) { // 当到达 target 头部时，找到位置，返回索引
                printf("%d", j);
                return 0;
            }
            i--;
        }
        j--;
    }
    printf("-1");
    return 0;
}

时间复杂度：O(n)

太阳能板的最大面积

Sun, 17 Jul 2022 22:47:42 +0800

题目描述

给航天器一侧加装长方形和正方形的太阳能板,需要先安装两个支柱,再在支柱的中间部分固定太阳能板;但航天器不同位置的支柱长度不同,太阳能板的安装面积受限于最短一侧的那支支柱的长度。
现提供一组整型数组的支柱高度数据，假设每个支柱间的距离相等为一个单位长度，计算如何选择两根支柱可以使太阳能板的面积最大。

输入描述

10,9,8,7,6,5,4,3,2,1
注释，支柱至少有两根，最多10000根，能支持的高度范围1~10^9的整数.
柱子的高度是无序的,例子中的递减是巧合。

输出描述

可以支持的最大太阳板面积:(10m高支柱和5m高支柱之间)
25

示例1

输入
10,9,8,7,6,5,4,3,2,1
输出
25
备注：10米高支柱和5米高支柱之间宽度为5，高度取小的支柱高度也是5，面积为25，任取其他两根支柱所能获得的面积都小于25 所以最大面积为25。
思路分析
10米高支柱和5米高支柱之间宽度为5，柱子的高度是无序的，所以宽等于高支柱的高减去低支柱的高。高度取小的支柱高度。任取其他两根支柱所能获得的面积，取其中最大的。

测试用例

1,2,3,4,5,6,7,8,9,10
25

10,9,8,7,6,5,4,3,2,1
25

1,7,8,9,8,5,8,9
30

C语言题解：

#include <stdio.h>
#include <stdlib.h>

#define MAX 10002

int main()
{
    int arr[MAX];
    int size = 0;
    char a;
    int tmp = 0;
    // 处理输入
    do {
        a = getchar();
        if (a >= '0' && a<= '9') {
            tmp = tmp*10 + a - '0'; // 将字符串转化为数字
        } else { // ,
            arr[size++] = tmp; // 将数字存储到数组中
            tmp = 0;
        }
    } while (a != '\n');

    int area;
    int max_area = 0;
    for (int i=0; i<size; i++) {
        int width = arr[i]; // 保存开始位置作为初始高度
        for (int j=i+1; j<size; j++) {
            width = width<arr[j] ? width : arr[j]; // 遍历获取最小高度
            area = width * (j-i);
            if (area > max_area) {
                max_area = area;
            }
        }
    }
    printf("%d", max_area);
    return 0;
}

golang 题解：

package main

import (
	"fmt"
)

func main() {
	var a byte
	var tmp int
	var arr []int
	for {
		fmt.Scanf("%c", &a)
		if a >= '0' && a <= '9' {
			tmp = tmp*10 + (int)(a - '0')
		} else {
			arr = append(arr, tmp)
			tmp = 0
		}
		if a == '\n' {
			break;
		}
	}
	var area int
	max_area := 0
	length := len(arr)
	for i:= 0; i<length; i++ {
		width := arr[i]
		for j:=i+1; j<length; j++ {
			if width > arr[j] {
				width = arr[j]
			}
			area = width * (j-i)
			if max_area < area {
				max_area = area;
			}
		}
		
	}
	fmt.Println(max_area)
}

时间复杂度 O(n^2);

字符串 - 子串查找之kmp算法

Sun, 10 Jul 2022 15:47:01 +0800

题目

计算模板串S在文本串T中出现了多少次？

输入描述

由大小写字母组成的两组字符串，第一行为模板字符串，第二行为文本串，找出模板字符串在文本串出现的次数

输出描述

输出模板字符串在文本串出现的次数

示例

ababd
abababdb

思路

1、暴力法:拿模板字符串和文本串逐个比较，时间复杂度 O(m*n)
2、KMP算法：
参考链接：KMP算法详解

题解

KMP - C语言

#include <string.h>
#include <stdio.h>
#include <stdlib.h>
/**
 * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
 *
 * 计算模板串S在文本串T中出现了多少次
 * @param S string字符串 模板串
 * @param T string字符串 文本串
 * @return int整型
 *
 * C语言声明定义全局变量请加上static，防止重复定义
 */
int next_array(const char *patten, int *next)
{
    const int len = strlen(patten);
    int i;
    int j = -1;
    next[0] = j;
    for (i=1; i<len; i++) {
        while (j>-1 && patten[i] != patten[j+1]) { // 当匹配表中有匹配信息后
            j = next[j];
        }
        if (patten[i] == patten[j+1]) { //ababc // -1,-1,0,1,-1
            j++;
        }
        next[i] = j;
    }
    return 0;
}

int kmp(char* S, char* T ) {
    const int lens = strlen(S);
    const int lent = strlen(T);
    if (lens == 0 && lent == 0) {
        return 0;
    }
    if (lens == 0) {
        return 0;
    }
    int *next = (int*)malloc(sizeof(int)*lens);
    next_array(S, next);
    print_array(next, lens);
    int i, j=-1, cnt=0;
    for (i=0; i<lent; i++) {
        while (j>-1 && T[i] != S[j+1]) {
            j = next[j];
        }
        if (T[i] == S[j+1]) {
            j++;
        }
        if (j == lens-1) {
            cnt++;
        }
    }
    free(next);
    return cnt;
}


int main(void)
{ 
    char S[256];
    char T[256];
    scanf("%s%s", S, T);
    printf("%d\n", kmp(S, T));
}

纪念我的父亲（一）

Mon, 04 Jul 2022 23:21:20 +0800

　　我的思绪常常飘到过去，飘到那个远离家乡的小村庄，那个父亲最后停留的地方。父亲大概也没有想到这辈子会那么短暂，而且最后的时间都在那个异乡度过。

　　那是一个安静的村落，具有广东特点的许多特点，有一个传承下来又翻新过的祠堂，祠堂前面有一个水塘，祠堂到水塘中间都用水泥硬化了路面，从村子路过时祠堂显得宽阔又庄严。祠堂旁边无一例外的有两颗巨大的榕树，这种树的寿命往往显示着村庄的历史，越是古老的村庄，祠堂旁边的树年龄越大，这只是它的一个功能；它的另外一个功能是在夏天给村里提供一处纳凉休息的地方，树下面有几张斑驳的石桌，村里面的老人和小孩都喜欢在午后到这里乘凉嬉戏。

　　但是父亲并没有居住在这个村子里，他是从外地过来这边做养殖的。在距离村子后面大约两三里地的地方，有三个池塘，一个比较大，另外两个比较小，它们位置的中间有两个小屋，青砖搭建的，一间用来放渔具和杂物的，另一件可能早期用来看鱼塘的吧，具体不得而知了；这间小屋由于建的比一般平房高一点，还又木板分了两层；占地面积大约五六个平方，地面一层放了一张一米五的竹板折叠床，一个电冰箱，一个自制的架子上面摆着一台电视；上面一层用木板架空，木板上面铺了彩棚布挡灰尘，紧接着用棉絮打底摆成一张床的形状，也可以住人，旁边摆了两个行李箱放衣服，又架了一根竹子挂着经常要穿的衣服；二楼距离地面两米多一点，中间用一个木头搭建的简易楼梯连接；为了能做饭，又在青砖房旁边搭建了一个棚子，周围用石棉瓦围住，就成了一个能挡雨遮风的厨房兼大厅，这个棚子比房子的占地面积还要大，整个建筑堆在一起看起来还是一间挺大的房子；房子前面有一块空地，空地连接着马路，房子左边不远处立了两扇铁门，将房子和马路隔开，这边就更像一块独立的院子了，父亲和母亲吃住就在这个院子里。

　　再往里面就是养殖的地方了，有一排砖墙和沥青油毡顶的保温房，是冬天用来给鸭苗保温的；再过去一点在水里搭建了一个棚子。这种棚子是养殖专业棚，大多用竹子做支撑和结构，在和岸边平齐的地方构建平台，平台是延伸在水面的，上面用一排排竹子水平绑在支撑的架子上；平台的竹子上面平铺一层钢丝网，用铁丝把钢丝网固定在竹子上，这样鸭子就不会掉下去，人在上面也如履平地，鸭粪可以通过钢丝网漏到水塘里喂鱼，这个就是在生物课上说的生态养殖。棚子的四周都用钢丝网围着，在朝水塘方向的左右两边都开了个下水坡，用来给鸭子下到水塘里喝水和活动；当然下水的区域是用渔网围住的，不然鸭子都满水塘跑了。这个养殖棚大约两百个平方，一栏能养两千到三千鸭子。往上走还有两个水塘，一个水塘比较小，棚子也就比较小，只能养一千到两千只鸭子；另外一个水塘比较大，也能养两千到三千鸭子。父亲就是在这样一个村落里做养殖专业户。

　　父亲在这边搞养殖，主营养殖番鸭。这种鸭子的名字我还闹了个笑话，因为大家平时都是说的家乡话，而湖南人发音“h”和“f”又不分，我一度以为这种鸭子叫“花鸭”，直到后面看到父亲的养殖书籍才知道这种鸭子叫番鸭。番鸭其实是海外引进的一种养殖肉鸭，故名“番”鸭；原产于中、南美洲热带地区，故主要养殖区域在我国南方；因为养殖出栏周期短，发育快，且肉质鲜美，有一定的消费市场，售价也比较一般鸭子高出不少，所以广东这边有大量的人员从事这块的养殖行业。父亲也养过别的品种的鸭子，但是都因为收益的问题而仅仅养了几批次；番鸭一直是首选品种，而且自己也爱吃。

　　父亲早在二零零五年就开始从事养殖，刚开始养殖的地方并不在这里，而是在花都炭步。一般养殖棚三到五年就因为竹子结构的寿命问题报废，维修的成本和新建一个的成本差不多，而且由于鸭子的疫情关系，一旦养殖区域发生过鸭疫，那么后续的鸭子患上鸭疫的可能性更高，因此一般在一个区域养殖的时间不会太长。父亲在搬到这个地方之前，还待了几个别的地方，分别是花都横岗，赤坭，还有一个水库，最后才搬到这个叫司前白庙的地方，满打满算从事养殖有九年左右。

如何使用github+hugo搭建静态个人网站

Fri, 01 Jul 2022 21:42:39 +0800

1、github建仓

新建一个 GitHub 库
注册一个 GitHub 账号。如果你已有账号，直接登录。如果你没有账号，注册并登录。
打开 GitHub Pages 官网，浏览并了解 User or organization site 部分对应的操作步骤。 GitHub Pages
新建一个 GitHub repository，库名为 username.github.io，username 即你的 GitHub 账号 username，新建 repository

2、hugo下载

下载安装命令
Mac下使用命令：
brew install hugo
注意：需要提前安装 homebrew
检查安装状态：
查看 Hugo 是否安装成功，可通过下列命令检查版本号
hugo version

3、hugo建站

创建新的网站
新建一个工作目录，执行下列命令：
mkdir website; cd website
hugo new site my_blog_web
克隆网站主题
git clone https://github.com/xianmin/hugo-theme-jane.git theme # 将 jane 主题克隆至 "theme" 目录。
也可以到该网页选择自己喜欢的主题
Hugo Themes
编辑网站配置文件
在上述新建文件夹 website 下，拷贝 theme/jane 默认配置文件
cp theme/jane/dev-config.toml config.toml
具体配置参考文件描述
本地预览网页效果
执行下列命令，根据命令后提示打开网页，默认网址http://localhost:1313，即可预览网页
hugo server
构建网页
使用 hugo 命令可以构建网页，默认输出到 public 文件夹中

4、部署到github

进入 public 目录，初始化 Git 库。
cd public # 生成的 HTML 文件保存在 "public" 目录中
git init
将 Git 本地库关联至远程库。
git remote add origin git@github.com:username/username.github.io.git
提交你的修改至本地库。
git status # 查看当前修改状态。
git add . # 添加所有修改过的文件。你也可以只添加某个文件。
git commit -m "Add a new post" # "Add a new post" 是 commit message.
将你的修改推至远程库。
在 public 目录下，将修改推至远程库。
git push -u origin main
恭喜！现在你已经拥有了一个自己构建的博客网站。网址地址是： https://username.github.io

常见问题

git push fail 确认远程仓库名称是否和命令一致；
ssh 认证失败本地使用命令生成key；然后将 id_rsa.pub 的内容填充到 github->Settings->SSH and GPG Keys->Add New
ssh-keygen
上传成功后访问网址无法显示
注意选择github仓库下的配置：“root” or “docs”

关于我

Fri, 01 Jul 2022 21:38:52 +0800

苏坡特

英雄：蒸汽机器人
定位：辅助

“一枚齿轮的运转足以影响一切的运行。”——布里茨

MAC 升级 bash 并配置为默认程序

Sat, 31 Jul 2021 11:03:36 +0800

背景

　　在 MAC 环境下，默认的 bash 为 3.x 版本，有时候一些 shell 命令需要在高版本上才支持，所以需要对 bash 环境进行升级。
　　下列为 MAC 下升级及配置操作，备忘。

bash 升级

检查 bash 版本
bash --version
使用 homebrew 安装新版本
brew install bash
查看已安装版本
which -a bash
/usr/local/bin/bash 为新安装的版本
/bin/bash 为 MAC 自带版本
验证新版本
/usr/local/bin/bash --version

配置默认 bash 版本

编辑配置文件
sudo vim /etc/shells
把 /usr/local/bin/bash 添加到最后一行，再执行下列命令把 bash 切到最新版本
chsh -s /usr/local/bin/bash
验证最新版本
bash --version

其它

bash 新旧切换
chsh -s /usr/local/bin/bash
chsh -s /bin/bash
bash 配置文件
~/.bash_profile

[shell] 批量修改文件夹、文件名和文件内容

Fri, 30 Jul 2021 12:09:23 +0800

背景

　　在日常工作当中，偶尔会遇到需要修改文件夹名字，修改文件名字以及修改文件内容的情况；当修改的关键字为固定内容的时候，且数量很多时，如果用人工手动修改，会非常耗时且乏味无趣。
　　下列脚本为了解决这个问题提供了思路和实践。个人经验所学，实际使用可能会有一些问题，欢迎指教；脚本请按需采用。

　　例如：

将文件内容 cont 修改为 content
将文件名 file_xxx.c 修改为 files_xxx.c
将文件夹　dir1 修改为 direct1

脚本说明

修改文件内容

grep -rl ${key} --include="*.c" --exclude="*.bin" --exclude-dir=“tool” | xargs sed -i "s/${key}/${value}/g"

grep -rl ${key} --include="*.c" --exclude="*.bin" --exclude-dir=“tool”
提取关键字为 ${key} 的文件相对路径名，该文件路径的后缀为 .c，但是后缀不为 .bin，该文件的路径不能为 tool。

xargs sed -i "s/${key}/${value}/g"
替换文件中 ${key} 关键字为 ${value}，文件为前一条命令中的内容。MAC 系统下 sed -i 后面要接空格 “”，具体说明可搜索一下。

修改文件名

find . -name "*${key}*" -type f | sed -e "p;s/${key}/${value}/g" | xargs -n2 mv

find . -name "*${key}" -type f
找到一个文件，该文件名包含关键字 ${key}

修改文件夹名

find . -name "*${key}*" -type d | sed -e "p;s/${key}/${value}/g" | xargs -n2 mv
找到一个文件夹，该文件夹名包含关键字 ${key}

脚本示例

#/bin/bash
# define array
dirs=(
"demo"
"demo2"
)

# define a associate array，must in bash version 4
declare -A dic
dic=(
    [cont]="replace"
    [cont2]="replace2"
)

for dir in "${dirs[@]}"; do
    if [ -d "${dir}/" ]; then
        echo "${dir}"
        cd ${dir}
        for key in $(echo ${!dic[*]}); do
            value=${dic[${key}]}
            echo "${key} ==> ${value}"
            # 1.修改文件内容
            grep -rl ${key} --exclude="*.bin" --exclude-dir="tool" | xargs sed -i "" "s/${key}/${value}/g"
            # 3.修改文件夹名
            find . -name "*${key}*" -type d | sed -e "p;s/${key}/${value}/g" | xargs -n2 mv
            # 2.修改文件名
            find . -name "*${key}*" -type f | sed -e "p;s/${key}/${value}/g" | xargs -n2 mv
        done
        cd -
    else
        echo "dir not exist!"
    fi
done

问题

　　当替换的关键字内容有重复时，比如用 cont 替换 content，此时会由于内容重叠导致出现一些重复替换或无法替换的问题，请注意。

Math Preview

Mon, 04 Mar 2019 16:01:23 +0800

KaTeX and MathJax Comparison Demo, currently processed as KaTex

Repeating fractions

$$ \frac{1}{\Bigl(\sqrt{\phi \sqrt{5}}-\phi\Bigr) e^{\frac25 \pi}} \equiv 1+\frac{e^{-2\pi}} {1+\frac{e^{-4\pi}} {1+\frac{e^{-6\pi}} {1+\frac{e^{-8\pi}} {1+\cdots} } } } $$

Summation notation

$$ \left( \sum_{k=1}^n a_k b_k \right)^2 \leq \left( \sum_{k=1}^n a_k^2 \right) \left( \sum_{k=1}^n b_k^2 \right) $$

Sum of a Series

I broke up the next two examples into separate lines so it behaves better on a mobile phone. That’s why they include \displaystyle.

$$ \displaystyle\sum_{i=1}^{k+1}i $$

$$ \displaystyle= \left(\sum_{i=1}^{k}i\right) +(k+1) $$

$$ \displaystyle= \frac{k(k+1)}{2}+k+1 $$

$$ \displaystyle= \frac{k(k+1)+2(k+1)}{2} $$

$$ \displaystyle= \frac{(k+1)(k+2)}{2} $$

$$ \displaystyle= \frac{(k+1)((k+1)+1)}{2} $$

Product notation

$$ \displaystyle 1 + \frac{q^2}{(1-q)}+\frac{q^6}{(1-q)(1-q^2)}+\cdots = \displaystyle \prod_{j=0}^{\infty}\frac{1}{(1-q^{5j+2})(1-q^{5j+3})}, \displaystyle\text{ for }\lvert q\rvert < 1. $$

Inline math

And here is some in-line math: $$ k_{n+1} = n^2 + k_n^2 - k_{n-1} $$ , followed by some more text.

Greek Letters

$$ \Gamma\ \Delta\ \Theta\ \Lambda\ \Xi\ \Pi\ \Sigma\ \Upsilon\ \Phi\ \Psi\ \Omega \alpha\ \beta\ \gamma\ \delta\ \epsilon\ \zeta\ \eta\ \theta\ \iota\ \kappa\ \lambda\ \mu\ \nu\ \xi \ \omicron\ \pi\ \rho\ \sigma\ \tau\ \upsilon\ \phi\ \chi\ \psi\ \omega\ \varepsilon\ \vartheta\ \varpi\ \varrho\ \varsigma\ \varphi $$

Arrows

$$ \gets\ \to\ \leftarrow\ \rightarrow\ \uparrow\ \Uparrow\ \downarrow\ \Downarrow\ \updownarrow\ \Updownarrow $$

$$ \Leftarrow\ \Rightarrow\ \leftrightarrow\ \Leftrightarrow\ \mapsto\ \hookleftarrow \leftharpoonup\ \leftharpoondown\ \rightleftharpoons\ \longleftarrow\ \Longleftarrow\ \longrightarrow $$

$$ \Longrightarrow\ \longleftrightarrow\ \Longleftrightarrow\ \longmapsto\ \hookrightarrow\ \rightharpoonup $$

$$ \rightharpoondown\ \leadsto\ \nearrow\ \searrow\ \swarrow\ \nwarrow $$

Symbols

$$ \surd\ \barwedge\ \veebar\ \odot\ \oplus\ \otimes\ \oslash\ \circledcirc\ \boxdot\ \bigtriangleup $$

$$ \bigtriangledown\ \dagger\ \diamond\ \star\ \triangleleft\ \triangleright\ \angle\ \infty\ \prime\ \triangle $$

Calculus

$$ \int u \frac{dv}{dx},dx=uv-\int \frac{du}{dx}v,dx $$

$$ f(x) = \int_{-\infty}^\infty \hat f(\xi),e^{2 \pi i \xi x} $$

$$ \oint \vec{F} \cdot d\vec{s}=0 $$

Lorenz Equations

$$ \begin{aligned} \dot{x} & = \sigma(y-x) \ \dot{y} & = \rho x - y - xz \ \dot{z} & = -\beta z + xy \end{aligned} $$

Cross Product

This works in KaTeX, but the separation of fractions in this environment is not so good.

$$ \mathbf{V}_1 \times \mathbf{V}_2 = \begin{vmatrix} \mathbf{i} & \mathbf{j} & \mathbf{k} \ \frac{\partial X}{\partial u} & \frac{\partial Y}{\partial u} & 0 \ \frac{\partial X}{\partial v} & \frac{\partial Y}{\partial v} & 0 \end{vmatrix} $$

Here’s a workaround: make the fractions smaller with an extra class that targets the spans with “mfrac” class (makes no difference in the MathJax case):

Accents

$$ \hat{x}\ \vec{x}\ \ddot{x} $$

Stretchy brackets

$$ \left(\frac{x^2}{y^3}\right) $$

Evaluation at limits

$$ \left.\frac{x^3}{3}\right|_0^1 $$

Case definitions

$$ f(n) = \begin{cases} \frac{n}{2}, & \text{if } n\text{ is even} \ 3n+1, & \text{if } n\text{ is odd} \end{cases} $$

Maxwell’s Equations

$$ \begin{aligned} \nabla \times \vec{\mathbf{B}} -, \frac1c, \frac{\partial\vec{\mathbf{E}}}{\partial t} & = \frac{4\pi}{c}\vec{\mathbf{j}} \ \nabla \cdot \vec{\mathbf{E}} & = 4 \pi \rho \ \nabla \times \vec{\mathbf{E}}, +, \frac1c, \frac{\partial\vec{\mathbf{B}}}{\partial t} & = \vec{\mathbf{0}} \ \nabla \cdot \vec{\mathbf{B}} & = 0 \end{aligned} $$

These equations are quite cramped. We can add vertical spacing using (for example) [1em] after each line break (\). as you can see here:

$$ \begin{aligned} \nabla \times \vec{\mathbf{B}} -, \frac1c, \frac{\partial\vec{\mathbf{E}}}{\partial t} & = \frac{4\pi}{c}\vec{\mathbf{j}} \[1em] \nabla \cdot \vec{\mathbf{E}} & = 4 \pi \rho \[0.5em] \nabla \times \vec{\mathbf{E}}, +, \frac1c, \frac{\partial\vec{\mathbf{B}}}{\partial t} & = \vec{\mathbf{0}} \[1em] \nabla \cdot \vec{\mathbf{B}} & = 0 \end{aligned} $$

Statistics

Definition of combination:

$$ \frac{n!}{k!(n-k)!} = {^n}C_k {n \choose k} $$

Fractions on fractions

$$ \frac{\frac{1}{x}+\frac{1}{y}}{y-z} $$

n-th root

$$ \sqrt[n]{1+x+x^2+x^3+\ldots} $$

Matrices

$$ \begin{pmatrix} a_{11} & a_{12} & a_{13}\ a_{21} & a_{22} & a_{23}\ a_{31} & a_{32} & a_{33} \end{pmatrix} \begin{bmatrix} 0 & \cdots & 0 \ \vdots & \ddots & \vdots \ 0 & \cdots & 0 \end{bmatrix} $$

Punctuation

$$ f(x) = \sqrt{1+x} \quad (x \ge -1) f(x) \sim x^2 \quad (x\to\infty) $$

Now with punctuation:

$$ f(x) = \sqrt{1+x}, \quad x \ge -1 f(x) \sim x^2, \quad x\to\infty $$

Shortcodes Preview

Sun, 04 Mar 2018 16:01:23 +0800

What a Shortcode is

Hugo loves Markdown because of its simple content format, but there are times when Markdown falls short. Often, content authors are forced to add raw HTML (e.g., video <iframes>) to Markdown content. We think this contradicts the beautiful simplicity of Markdown’s syntax.

Hugo created shortcodes to circumvent these limitations.

A shortcode is a simple snippet inside a content file that Hugo will render using a predefined template. Note that shortcodes will not work in template files. If you need the type of drop-in functionality that shortcodes provide but in a template, you most likely want a [partial template][partials] instead.

In addition to cleaner Markdown, shortcodes can be updated any time to reflect new classes, techniques, or standards. At the point of site generation, Hugo shortcodes will easily merge in your changes. You avoid a possibly complicated search and replace operation.

More details: https://gohugo.io/content-management/shortcodes/

blockquotes

Normal quote:

This is a simple quote.

Quote with author:

This is a quote with only an Author named Author2.

Author2

Quote with author and source:

This is a quote from Author3 and source “source.”

Author3 Source

Quote with author and link:

This is a quote from Author4 and links to https://www.google.com.

Author4 google.com

Quote with author, link and title:

This is a quote from Author5 and links to https://www.google.com with title “Google.”

Author5 Google

Quote with author and a link longer than 32 characters, string is first cut at 32 characters then everything after the last forward slash is removed

This is a quote from Author5 and links to https://twitter.com/CryptoGangsta/status/716427930126196737 which is longer than 32 characters. And this is a new line in the quote with the HTML br tag.

Author6 twitter.com/CryptoGangsta/...

Test from the Octopress blockquote page at: http://octopress.org/docs/plugins/blockquote/

Over the past 24 hours I’ve been reflecting on my life & I’ve realized only one thing. I need a medieval battle axe.

@allanbranch twitter.com/allanbranch/status/...

music

gist

We can embed the gist in our content via username and gist ID pulled from the URL:

{{< gist spf13 7896402 >}}

Display:

expand

The Expand shortcode displays an expandable/collapsible section of text on your page. Here is an example

Is this learn theme rocks ?

Yes !.

Usage

this shortcode takes exactly one optional parameter to define the text that appears next to the expand/collapse icon. (default is “Click to expand”)

{{< expand "Is this learn theme rocks ?" >}}
Yes !.
{{< /expand >}}

youtube

vimeo

youku

Image Preview

Sat, 03 Mar 2018 16:01:23 +0800

Thanks for liwenyip/hugo-easy-gallery & Zebradil · Pull Request #48 .

Now, we could use {{< gallery >}} shortcode in hugo-theme-jane.

Normal Image

This is an image in static/image folder.

![This is an image in `static/image` folder.](/image/example.jpg)

`{{< figure >}}` shortcode

figure image with title

{{< figure src="/image/example.jpg" title="figure image with title" >}}

figure image with caption

{{< figure src="/image/example.jpg" caption="figure image with caption figure image with caption figure image with caption figure image with caption figure image with caption" >}}

more `{{< figure >}}` shortcode usage

Specifying your image files:

{{< figure src="thumb.jpg" link="image.jpg" >}} will use thumb.jpg for thumbnail and image.jpg for lightbox
{{< figure src="image.jpg" >}} or {{< figure link="image.jpg" >}} will use image.jpg for both thumbnail and lightbox
{{< figure link="image.jpg" thumb="-small" >}} will use image-small.jpg for thumbnail and image.jpg for lightbox

Optional parameters:

All the features/parameters of Hugo’s built-in figure shortcode work as normal, i.e. src, link, title, caption, class, attr (attribution), attrlink, alt
size (e.g. size="1024x768") pre-defines the image size for PhotoSwipe. Use this option if you don’t want to pre-load the linked image to determine its size.
class allows you to set any custom classes you want on the <figure> tag.

Optional parameters for standalone {{< figure >}} shortcodes only (i.e. don’t use on {{< figure >}} inside {{< gallery >}} - strange things may happen if you do):

caption-position and caption-effect work the same as for the {{< gallery >}} shortcode (see below).
width defines the max-width of the image displayed on the page. If using a thumbnail for a standalone figure, set this equal to your thumbnail’s native width to make the captions behave properly (or feel free to come up with a better solution and submit a pull request :-)). Also use this option if you don’t have a thumbnail and you don’t want the hi-res image to take up the entire width of the screen/container.
class="no-photoswipe" prevents a <figure> from being loaded into PhotoSwipe. If you click on the figure you’ll instead a good ol’ fashioned hyperlink to a bigger image (or - if you haven’t specified a bigger image - the same one).

`{{< gallery >}}` shortcode

simple gallery

To specify a directory of image files:

{{< gallery dir="/img/your-directory-of-images/" >}}

The images are automatically captioned with the file name.
[image].jpg is used for the hi-res image, and [image]-thumb.jpg is used for the thumbnails.
If [image]-thumb.jpg doesn’t exist, then [image].jpg will be used for both hi-res and thumbnail images.
The default thumbnail suffix is -thumb, but you can specify a different one e.g. thumb="-small" or thumb="_150x150".

To specify individual image files

{{< gallery >}}
  {{< figure src="image1.jpg" >}}
  {{< figure src="image2.jpg" >}}
  {{< figure src="image3.jpg" >}}
{{< /gallery >}}

Optional parameters:

caption-position - determines the captions’ position over the image. Options:
- bottom (default)
- center
- none hides captions on the page (they will only show in PhotoSwipe)
caption-effect - determines if/how captions appear upon hover. Options:
- slide (default)
- fade
- none (captions always visible)
hover-effect - determines if/how images change upon hover. Options:
- zoom (default)
- grow
- shrink
- slideup
- slidedown
- none
hover-transition - determines if/how images change upon hover. Options:
- not set - smooth transition (default)
- none - hard transition

Shortcodes Notice Preview

Sat, 03 Mar 2018 16:01:23 +0800

normal use

Note example:

{{% notice note %}}
A notice disclaimer
{{% /notice %}}

Result:

You could custom title :

{{% notice note 笔记 %}}
A notice disclaimer
{{% /notice %}}

tip

{{% notice tip %}}
A tip disclaimer
{{% /tip %}}

info

{{% notice info %}}
A info disclaimer
{{% /notice %}}

warning

{{% notice warning %}}
A warning disclaimer
{{% /notice %}}

Jane-Theme Footnote Preview

Thu, 01 Mar 2018 16:01:23 +0800

Hugo-theme-jane optimized for footnote. When you mouse hover the footnote¹ , footnote content will be displayed.

Footnote-1

You can create footnotes like this[^footnote].

[^footnote]: Here is the *text* of the **footnote**.

will produce:

You can create footnotes like this².

Mouse on the ‘footnote’ superscript to see content of the footnote.

Footnote-2

You can create footnotes like this[^footnote2].

[^footnote2]: Here is the *text* of the **footnote**.

will produce:

You can create footnotes like this³.

Mouse on the ‘footnote’ superscript to see content of the footnote.

Footnote-3

You can create footnotes like this[^footnote].

[^footnote]: Here is the *text* of the **footnote**.

will produce:

You can create footnotes like this⁴.

Mouse on the ‘footnote’ superscript to see content of the footnote.

Footnote-4

You can create footnotes like this[^footnote].

[^footnote]: Here is the *text* of the **footnote**.

will produce:

You can create footnotes like this⁵.

Mouse on the ‘footnote’ superscript to see content of the footnote.

Footnote-5

You can create footnotes like this[^footnote].

[^footnote]: Here is the *text* of the **footnote**.

will produce dddddddddddddddddddddddddddddddddddddddddddddd:

You can create footnotes like this⁶.

Mouse on the ‘footnote’ superscript to see content of the footnote.

example footnote show. ↩︎
Here is the text of the footnote-1. ↩︎
Here is the text of the footnote-2. Here is the text of the footnote-2. Here is the text of the footnote-2. Here is the text of the footnote-2. Here is the text of the footnote-2. The world’s fastest framework for building websites | Hugo ↩︎
Here is the text of the footnote-3. ↩︎
Here is the text of the footnote-4. ↩︎
Here is the text of the footnote-5. ↩︎

English Creating a New Theme

Thu, 31 Aug 2017 15:43:48 +0800

Introduction

This tutorial will show you how to create a simple theme in Hugo. I assume that you are familiar with HTML, the bash command line, and that you are comfortable using Markdown to format content. I’ll explain how Hugo uses templates and how you can organize your templates to create a theme. I won’t cover using CSS to style your theme.

We’ll start with creating a new site with a very basic template. Then we’ll add in a few pages and posts. With small variations on that, you will be able to create many different types of web sites.

In this tutorial, commands that you enter will start with the “$” prompt. The output will follow. Lines that start with “#” are comments that I’ve added to explain a point. When I show updates to a file, the “:wq” on the last line means to save the file.

Here’s an example:

## this is a comment
$ echo this is a command
this is a command

## edit the file
$vi foo.md
+++
date = "2014-09-28"
title = "creating a new theme"
+++

bah and humbug
:wq

## show it
$ cat foo.md
+++
date = "2014-09-28"
title = "creating a new theme"
+++

bah and humbug
$

Some Definitions

There are a few concepts that you need to understand before creating a theme.

Skins

Skins are the files responsible for the look and feel of your site. It’s the CSS that controls colors and fonts, it’s the Javascript that determines actions and reactions. It’s also the rules that Hugo uses to transform your content into the HTML that the site will serve to visitors.

You have two ways to create a skin. The simplest way is to create it in the layouts/ directory. If you do, then you don’t have to worry about configuring Hugo to recognize it. The first place that Hugo will look for rules and files is in the layouts/ directory so it will always find the skin.

Your second choice is to create it in a sub-directory of the themes/ directory. If you do, then you must always tell Hugo where to search for the skin. It’s extra work, though, so why bother with it?

The difference between creating a skin in layouts/ and creating it in themes/ is very subtle. A skin in layouts/ can’t be customized without updating the templates and static files that it is built from. A skin created in themes/, on the other hand, can be and that makes it easier for other people to use it.

The rest of this tutorial will call a skin created in the themes/ directory a theme.

Note that you can use this tutorial to create a skin in the layouts/ directory if you wish to. The main difference will be that you won’t need to update the site’s configuration file to use a theme.

The Home Page

The home page, or landing page, is the first page that many visitors to a site see. It is the index.html file in the root directory of the web site. Since Hugo writes files to the public/ directory, our home page is public/index.html.

Site Configuration File

When Hugo runs, it looks for a configuration file that contains settings that override default values for the entire site. The file can use TOML, YAML, or JSON. I prefer to use TOML for my configuration files. If you prefer to use JSON or YAML, you’ll need to translate my examples. You’ll also need to change the name of the file since Hugo uses the extension to determine how to process it.

Hugo translates Markdown files into HTML. By default, Hugo expects to find Markdown files in your content/ directory and template files in your themes/ directory. It will create HTML files in your public/ directory. You can change this by specifying alternate locations in the configuration file.

Content

Content is stored in text files that contain two sections. The first section is the “front matter,” which is the meta-information on the content. The second section contains Markdown that will be converted to HTML.

Front Matter

The front matter is information about the content. Like the configuration file, it can be written in TOML, YAML, or JSON. Unlike the configuration file, Hugo doesn’t use the file’s extension to know the format. It looks for markers to signal the type. TOML is surrounded by “+++”, YAML by “---”, and JSON is enclosed in curly braces. I prefer to use TOML, so you’ll need to translate my examples if you prefer YAML or JSON.

The information in the front matter is passed into the template before the content is rendered into HTML.

Markdown

Content is written in Markdown which makes it easier to create the content. Hugo runs the content through a Markdown engine to create the HTML which will be written to the output file.

Template Files

Hugo uses template files to render content into HTML. Template files are a bridge between the content and presentation. Rules in the template define what content is published, where it’s published to, and how it will rendered to the HTML file. The template guides the presentation by specifying the style to use.

There are three types of templates: single, list, and partial. Each type takes a bit of content as input and transforms it based on the commands in the template.

Hugo uses its knowledge of the content to find the template file used to render the content. If it can’t find a template that is an exact match for the content, it will shift up a level and search from there. It will continue to do so until it finds a matching template or runs out of templates to try. If it can’t find a template, it will use the default template for the site.

Please note that you can use the front matter to influence Hugo’s choice of templates.

Single Template

A single template is used to render a single piece of content. For example, an article or post would be a single piece of content and use a single template.

List Template

A list template renders a group of related content. That could be a summary of recent postings or all articles in a category. List templates can contain multiple groups.

The homepage template is a special type of list template. Hugo assumes that the home page of your site will act as the portal for the rest of the content in the site.

Partial Template

A partial template is a template that can be included in other templates. Partial templates must be called using the “partial” template command. They are very handy for rolling up common behavior. For example, your site may have a banner that all pages use. Instead of copying the text of the banner into every single and list template, you could create a partial with the banner in it. That way if you decide to change the banner, you only have to change the partial template.

Create a New Site

Let’s use Hugo to create a new web site. I’m a Mac user, so I’ll create mine in my home directory, in the Sites folder. If you’re using Linux, you might have to create the folder first.

The “new site” command will create a skeleton of a site. It will give you the basic directory structure and a useable configuration file.

$ hugo new site ~/Sites/zafta
$ cd ~/Sites/zafta
$ ls -l
total 8
drwxr-xr-x  7 quoha  staff  238 Sep 29 16:49 .
drwxr-xr-x  3 quoha  staff  102 Sep 29 16:49 ..
drwxr-xr-x  2 quoha  staff   68 Sep 29 16:49 archetypes
-rw-r--r--  1 quoha  staff   82 Sep 29 16:49 config.toml
drwxr-xr-x  2 quoha  staff   68 Sep 29 16:49 content
drwxr-xr-x  2 quoha  staff   68 Sep 29 16:49 layouts
drwxr-xr-x  2 quoha  staff   68 Sep 29 16:49 static
$

Take a look in the content/ directory to confirm that it is empty.

The other directories (archetypes/, layouts/, and static/) are used when customizing a theme. That’s a topic for a different tutorial, so please ignore them for now.

Generate the HTML For the New Site

Running the hugo command with no options will read all the available content and generate the HTML files. It will also copy all static files (that’s everything that’s not content). Since we have an empty site, it won’t do much, but it will do it very quickly.

$ hugo --verbose
INFO: 2014/09/29 Using config file: config.toml
INFO: 2014/09/29 syncing from /Users/quoha/Sites/zafta/static/ to /Users/quoha/Sites/zafta/public/
WARN: 2014/09/29 Unable to locate layout: [index.html _default/list.html _default/single.html]
WARN: 2014/09/29 Unable to locate layout: [404.html]
0 draft content
0 future content
0 pages created
0 tags created
0 categories created
in 2 ms
$

The “--verbose” flag gives extra information that will be helpful when we build the template. Every line of the output that starts with “INFO:” or “WARN:” is present because we used that flag. The lines that start with “WARN:” are warning messages. We’ll go over them later.

We can verify that the command worked by looking at the directory again.

$ ls -l
total 8
drwxr-xr-x  2 quoha  staff   68 Sep 29 16:49 archetypes
-rw-r--r--  1 quoha  staff   82 Sep 29 16:49 config.toml
drwxr-xr-x  2 quoha  staff   68 Sep 29 16:49 content
drwxr-xr-x  2 quoha  staff   68 Sep 29 16:49 layouts
drwxr-xr-x  4 quoha  staff  136 Sep 29 17:02 public
drwxr-xr-x  2 quoha  staff   68 Sep 29 16:49 static
$

See that new public/ directory? Hugo placed all generated content there. When you’re ready to publish your web site, that’s the place to start. For now, though, let’s just confirm that we have what we’d expect from a site with no content.

$ ls -l public
total 16
-rw-r--r--  1 quoha  staff  416 Sep 29 17:02 index.xml
-rw-r--r--  1 quoha  staff  262 Sep 29 17:02 sitemap.xml
$

Hugo created two XML files, which is standard, but there are no HTML files.

Test the New Site

Verify that you can run the built-in web server. It will dramatically shorten your development cycle if you do. Start it by running the “server” command. If it is successful, you will see output similar to the following:

$ hugo server --verbose
INFO: 2014/09/29 Using config file: /Users/quoha/Sites/zafta/config.toml
INFO: 2014/09/29 syncing from /Users/quoha/Sites/zafta/static/ to /Users/quoha/Sites/zafta/public/
WARN: 2014/09/29 Unable to locate layout: [index.html _default/list.html _default/single.html]
WARN: 2014/09/29 Unable to locate layout: [404.html]
0 draft content
0 future content
0 pages created
0 tags created
0 categories created
in 2 ms
Serving pages from /Users/quoha/Sites/zafta/public
Web Server is available at http://localhost:1313
Press Ctrl+C to stop

Connect to the listed URL (it’s on the line that starts with “Web Server”). If everything is working correctly, you should get a page that shows the following:

index.xml
sitemap.xml

That’s a listing of your public/ directory. Hugo didn’t create a home page because our site has no content. When there’s no index.html file in a directory, the server lists the files in the directory, which is what you should see in your browser.

Let’s go back and look at those warnings again.

WARN: 2014/09/29 Unable to locate layout: [index.html _default/list.html _default/single.html]
WARN: 2014/09/29 Unable to locate layout: [404.html]

That second warning is easier to explain. We haven’t created a template to be used to generate “page not found errors.” The 404 message is a topic for a separate tutorial.

Now for the first warning. It is for the home page. You can tell because the first layout that it looked for was “index.html.” That’s only used by the home page.

I like that the verbose flag causes Hugo to list the files that it’s searching for. For the home page, they are index.html, _default/list.html, and _default/single.html. There are some rules that we’ll cover later that explain the names and paths. For now, just remember that Hugo couldn’t find a template for the home page and it told you so.

At this point, you’ve got a working installation and site that we can build upon. All that’s left is to add some content and a theme to display it.

Create a New Theme

Hugo doesn’t ship with a default theme. There are a few available (I counted a dozen when I first installed Hugo) and Hugo comes with a command to create new themes.

We’re going to create a new theme called “zafta.” Since the goal of this tutorial is to show you how to fill out the files to pull in your content, the theme will not contain any CSS. In other words, ugly but functional.

All themes have opinions on content and layout. For example, Zafta uses “post” over “blog”. Strong opinions make for simpler templates but differing opinions make it tougher to use themes. When you build a theme, consider using the terms that other themes do.

Create a Skeleton

Use the hugo “new” command to create the skeleton of a theme. This creates the directory structure and places empty files for you to fill out.

$ hugo new theme zafta

$ ls -l
total 8
drwxr-xr-x  2 quoha  staff   68 Sep 29 16:49 archetypes
-rw-r--r--  1 quoha  staff   82 Sep 29 16:49 config.toml
drwxr-xr-x  2 quoha  staff   68 Sep 29 16:49 content
drwxr-xr-x  2 quoha  staff   68 Sep 29 16:49 layouts
drwxr-xr-x  4 quoha  staff  136 Sep 29 17:02 public
drwxr-xr-x  2 quoha  staff   68 Sep 29 16:49 static
drwxr-xr-x  3 quoha  staff  102 Sep 29 17:31 themes

$ find themes -type f | xargs ls -l
-rw-r--r--  1 quoha  staff  1081 Sep 29 17:31 themes/zafta/LICENSE.md
-rw-r--r--  1 quoha  staff     0 Sep 29 17:31 themes/zafta/archetypes/default.md
-rw-r--r--  1 quoha  staff     0 Sep 29 17:31 themes/zafta/layouts/_default/list.html
-rw-r--r--  1 quoha  staff     0 Sep 29 17:31 themes/zafta/layouts/_default/single.html
-rw-r--r--  1 quoha  staff     0 Sep 29 17:31 themes/zafta/layouts/index.html
-rw-r--r--  1 quoha  staff     0 Sep 29 17:31 themes/zafta/layouts/partials/footer.html
-rw-r--r--  1 quoha  staff     0 Sep 29 17:31 themes/zafta/layouts/partials/header.html
-rw-r--r--  1 quoha  staff    93 Sep 29 17:31 themes/zafta/theme.toml
$

The skeleton includes templates (the files ending in .html), license file, a description of your theme (the theme.toml file), and an empty archetype.

Please take a minute to fill out the theme.toml and LICENSE.md files. They’re optional, but if you’re going to be distributing your theme, it tells the world who to praise (or blame). It’s also nice to declare the license so that people will know how they can use the theme.

$ vi themes/zafta/theme.toml
author = "michael d henderson"
description = "a minimal working template"
license = "MIT"
name = "zafta"
source_repo = ""
tags = ["tags", "categories"]
:wq

## also edit themes/zafta/LICENSE.md and change
## the bit that says "YOUR_NAME_HERE"

Note that the the skeleton’s template files are empty. Don’t worry, we’ll be changing that shortly.

$ find themes/zafta -name '*.html' | xargs ls -l
-rw-r--r--  1 quoha  staff  0 Sep 29 17:31 themes/zafta/layouts/_default/list.html
-rw-r--r--  1 quoha  staff  0 Sep 29 17:31 themes/zafta/layouts/_default/single.html
-rw-r--r--  1 quoha  staff  0 Sep 29 17:31 themes/zafta/layouts/index.html
-rw-r--r--  1 quoha  staff  0 Sep 29 17:31 themes/zafta/layouts/partials/footer.html
-rw-r--r--  1 quoha  staff  0 Sep 29 17:31 themes/zafta/layouts/partials/header.html
$

Update the Configuration File to Use the Theme

Now that we’ve got a theme to work with, it’s a good idea to add the theme name to the configuration file. This is optional, because you can always add “-t zafta” on all your commands. I like to put it the configuration file because I like shorter command lines. If you don’t put it in the configuration file or specify it on the command line, you won’t use the template that you’re expecting to.

Edit the file to add the theme, add a title for the site, and specify that all of our content will use the TOML format.

$ vi config.toml
theme = "zafta"
baseurl = ""
languageCode = "en-us"
title = "zafta - totally refreshing"
MetaDataFormat = "toml"
:wq

$

Generate the Site

Now that we have an empty theme, let’s generate the site again.

$ hugo --verbose
INFO: 2014/09/29 Using config file: /Users/quoha/Sites/zafta/config.toml
INFO: 2014/09/29 syncing from /Users/quoha/Sites/zafta/themes/zafta/static/ to /Users/quoha/Sites/zafta/public/
INFO: 2014/09/29 syncing from /Users/quoha/Sites/zafta/static/ to /Users/quoha/Sites/zafta/public/
WARN: 2014/09/29 Unable to locate layout: [404.html theme/404.html]
0 draft content
0 future content
0 pages created
0 tags created
0 categories created
in 2 ms
$

Did you notice that the output is different? The warning message for the home page has disappeared and we have an additional information line saying that Hugo is syncing from the theme’s directory.

Let’s check the public/ directory to see what Hugo’s created.

$ ls -l public
total 16
drwxr-xr-x  2 quoha  staff   68 Sep 29 17:56 css
-rw-r--r--  1 quoha  staff    0 Sep 29 17:56 index.html
-rw-r--r--  1 quoha  staff  407 Sep 29 17:56 index.xml
drwxr-xr-x  2 quoha  staff   68 Sep 29 17:56 js
-rw-r--r--  1 quoha  staff  243 Sep 29 17:56 sitemap.xml
$

Notice four things:

Hugo created a home page. This is the file public/index.html.
Hugo created a css/ directory.
Hugo created a js/ directory.
Hugo claimed that it created 0 pages. It created a file and copied over static files, but didn’t create any pages. That’s because it considers a “page” to be a file created directly from a content file. It doesn’t count things like the index.html files that it creates automatically.

The Home Page

Hugo supports many different types of templates. The home page is special because it gets its own type of template and its own template file. The file, layouts/index.html, is used to generate the HTML for the home page. The Hugo documentation says that this is the only required template, but that depends. Hugo’s warning message shows that it looks for three different templates:

WARN: 2014/09/29 Unable to locate layout: [index.html _default/list.html _default/single.html]

If it can’t find any of these, it completely skips creating the home page. We noticed that when we built the site without having a theme installed.

When Hugo created our theme, it created an empty home page template. Now, when we build the site, Hugo finds the template and uses it to generate the HTML for the home page. Since the template file is empty, the HTML file is empty, too. If the template had any rules in it, then Hugo would have used them to generate the home page.

$ find . -name index.html | xargs ls -l
-rw-r--r--  1 quoha  staff  0 Sep 29 20:21 ./public/index.html
-rw-r--r--  1 quoha  staff  0 Sep 29 17:31 ./themes/zafta/layouts/index.html
$

The Magic of Static

Hugo does two things when generating the site. It uses templates to transform content into HTML and it copies static files into the site. Unlike content, static files are not transformed. They are copied exactly as they are.

Hugo assumes that your site will use both CSS and JavaScript, so it creates directories in your theme to hold them. Remember opinions? Well, Hugo’s opinion is that you’ll store your CSS in a directory named css/ and your JavaScript in a directory named js/. If you don’t like that, you can change the directory names in your theme directory or jane delete them completely. Hugo’s nice enough to offer its opinion, then behave nicely if you disagree.

$ find themes/zafta -type d | xargs ls -ld
drwxr-xr-x  7 quoha  staff  238 Sep 29 17:38 themes/zafta
drwxr-xr-x  3 quoha  staff  102 Sep 29 17:31 themes/zafta/archetypes
drwxr-xr-x  5 quoha  staff  170 Sep 29 17:31 themes/zafta/layouts
drwxr-xr-x  4 quoha  staff  136 Sep 29 17:31 themes/zafta/layouts/_default
drwxr-xr-x  4 quoha  staff  136 Sep 29 17:31 themes/zafta/layouts/partials
drwxr-xr-x  4 quoha  staff  136 Sep 29 17:31 themes/zafta/static
drwxr-xr-x  2 quoha  staff   68 Sep 29 17:31 themes/zafta/static/css
drwxr-xr-x  2 quoha  staff   68 Sep 29 17:31 themes/zafta/static/js
$

The Theme Development Cycle

When you’re working on a theme, you will make changes in the theme’s directory, rebuild the site, and check your changes in the browser. Hugo makes this very easy:

Purge the public/ directory.
Run the built in web server in watch mode.
Open your site in a browser.
Update the theme.
Glance at your browser window to see changes.
Return to step 4.

I’ll throw in one more opinion: never work on a theme on a live site. Always work on a copy of your site. Make changes to your theme, test them, then copy them up to your site. For added safety, use a tool like Git to keep a revision history of your content and your theme. Believe me when I say that it is too easy to lose both your mind and your changes.

Check the main Hugo site for information on using Git with Hugo.

Purge the public/ Directory

When generating the site, Hugo will create new files and update existing ones in the public/ directory. It will not delete files that are no longer used. For example, files that were created in the wrong directory or with the wrong title will remain. If you leave them, you might get confused by them later. I recommend cleaning out your site prior to generating it.

Note: If you’re building on an SSD, you should ignore this. Churning on a SSD can be costly.

Hugo’s Watch Option

Hugo’s “--watch” option will monitor the content/ and your theme directories for changes and rebuild the site automatically.

Live Reload

Hugo’s built in web server supports live reload. As pages are saved on the server, the browser is told to refresh the page. Usually, this happens faster than you can say, “Wow, that’s totally amazing.”

Development Commands

Use the following commands as the basis for your workflow.

## purge old files. hugo will recreate the public directory.
##
$ rm -rf public
##
## run hugo in watch mode
##
$ hugo server --watch --verbose

Here’s sample output showing Hugo detecting a change to the template for the home page. Once generated, the web browser automatically reloaded the page. I’ve said this before, it’s amazing.

$ rm -rf public
$ hugo server --watch --verbose
INFO: 2014/09/29 Using config file: /Users/quoha/Sites/zafta/config.toml
INFO: 2014/09/29 syncing from /Users/quoha/Sites/zafta/themes/zafta/static/ to /Users/quoha/Sites/zafta/public/
INFO: 2014/09/29 syncing from /Users/quoha/Sites/zafta/static/ to /Users/quoha/Sites/zafta/public/
WARN: 2014/09/29 Unable to locate layout: [404.html theme/404.html]
0 draft content
0 future content
0 pages created
0 tags created
0 categories created
in 2 ms
Watching for changes in /Users/quoha/Sites/zafta/content
Serving pages from /Users/quoha/Sites/zafta/public
Web Server is available at http://localhost:1313
Press Ctrl+C to stop
INFO: 2014/09/29 File System Event: ["/Users/quoha/Sites/zafta/themes/zafta/layouts/index.html": MODIFY|ATTRIB]
Change detected, rebuilding site

WARN: 2014/09/29 Unable to locate layout: [404.html theme/404.html]
0 draft content
0 future content
0 pages created
0 tags created
0 categories created
in 1 ms

Update the Home Page Template

The home page is one of a few special pages that Hugo creates automatically. As mentioned earlier, it looks for one of three files in the theme’s layout/ directory:

index.html
_default/list.html
_default/single.html

We could update one of the default templates, but a good design decision is to update the most specific template available. That’s not a hard and fast rule (in fact, we’ll break it a few times in this tutorial), but it is a good generalization.

Make a Static Home Page

Right now, that page is empty because we don’t have any content and we don’t have any logic in the template. Let’s change that by adding some text to the template.

$ vi themes/zafta/layouts/index.html
<!DOCTYPE html>
<html>
<body>
  <p>hugo says hello!</p>
</body>
</html>
:wq

$

Build the web site and then verify the results.

$ hugo --verbose
INFO: 2014/09/29 Using config file: /Users/quoha/Sites/zafta/config.toml
INFO: 2014/09/29 syncing from /Users/quoha/Sites/zafta/themes/zafta/static/ to /Users/quoha/Sites/zafta/public/
INFO: 2014/09/29 syncing from /Users/quoha/Sites/zafta/static/ to /Users/quoha/Sites/zafta/public/
WARN: 2014/09/29 Unable to locate layout: [404.html theme/404.html]
0 draft content
0 future content
0 pages created
0 tags created
0 categories created
in 2 ms

$ find public -type f -name '*.html' | xargs ls -l
-rw-r--r--  1 quoha  staff  78 Sep 29 21:26 public/index.html

$ cat public/index.html
<!DOCTYPE html>
<html>
<body>
  <p>hugo says hello!</p>
</html>

Live Reload

Note: If you’re running the server with the --watch option, you’ll see different content in the file:

$ cat public/index.html
<!DOCTYPE html>
<html>
<body>
  <p>hugo says hello!</p>
<script>document.write('<script src="http://'
        + (location.host || 'localhost').split(':')[0]
    + ':1313/livereload.js?mindelay=10"></'
        + 'script>')</script></body>
</html>

When you use --watch, the Live Reload script is added by Hugo. Look for live reload in the documentation to see what it does and how to disable it.

Build a “Dynamic” Home Page

“Dynamic home page?” Hugo’s a static web site generator, so this seems an odd thing to say. I mean let’s have the home page automatically reflect the content in the site every time Hugo builds it. We’ll use iteration in the template to do that.

Create New Posts

Now that we have the home page generating static content, let’s add some content to the site. We’ll display these posts as a list on the home page and on their own page, too.

Hugo has a command to generate a skeleton post, just like it does for sites and themes.

$ hugo --verbose new post/first.md
INFO: 2014/09/29 Using config file: /Users/quoha/Sites/zafta/config.toml
INFO: 2014/09/29 attempting to create  post/first.md of post
INFO: 2014/09/29 curpath: /Users/quoha/Sites/zafta/themes/zafta/archetypes/default.md
ERROR: 2014/09/29 Unable to Cast <nil> to map[string]interface{}

$

That wasn’t very nice, was it?

The “new” command uses an archetype to create the post file. Hugo created an empty default archetype file, but that causes an error when there’s a theme. For me, the workaround was to create an archetypes file specifically for the post type.

$ vi themes/zafta/archetypes/post.md
+++
Description = ""
Tags = []
Categories = []
+++
:wq

$ find themes/zafta/archetypes -type f | xargs ls -l
-rw-r--r--  1 quoha  staff   0 Sep 29 21:53 themes/zafta/archetypes/default.md
-rw-r--r--  1 quoha  staff  51 Sep 29 21:54 themes/zafta/archetypes/post.md

$ hugo --verbose new post/first.md
INFO: 2014/09/29 Using config file: /Users/quoha/Sites/zafta/config.toml
INFO: 2014/09/29 attempting to create  post/first.md of post
INFO: 2014/09/29 curpath: /Users/quoha/Sites/zafta/themes/zafta/archetypes/post.md
INFO: 2014/09/29 creating /Users/quoha/Sites/zafta/content/post/first.md
/Users/quoha/Sites/zafta/content/post/first.md created

$ hugo --verbose new post/second.md
INFO: 2014/09/29 Using config file: /Users/quoha/Sites/zafta/config.toml
INFO: 2014/09/29 attempting to create  post/second.md of post
INFO: 2014/09/29 curpath: /Users/quoha/Sites/zafta/themes/zafta/archetypes/post.md
INFO: 2014/09/29 creating /Users/quoha/Sites/zafta/content/post/second.md
/Users/quoha/Sites/zafta/content/post/second.md created

$ ls -l content/post
total 16
-rw-r--r--  1 quoha  staff  104 Sep 29 21:54 first.md
-rw-r--r--  1 quoha  staff  105 Sep 29 21:57 second.md

$ cat content/post/first.md
+++
Categories = []
Description = ""
Tags = []
date = "2014-09-29T21:54:53-05:00"
title = "first"

+++
my first post

$ cat content/post/second.md
+++
Categories = []
Description = ""
Tags = []
date = "2014-09-29T21:57:09-05:00"
title = "second"

+++
my second post

$

Build the web site and then verify the results.

$ rm -rf public
$ hugo --verbose
INFO: 2014/09/29 Using config file: /Users/quoha/Sites/zafta/config.toml
INFO: 2014/09/29 syncing from /Users/quoha/Sites/zafta/themes/zafta/static/ to /Users/quoha/Sites/zafta/public/
INFO: 2014/09/29 syncing from /Users/quoha/Sites/zafta/static/ to /Users/quoha/Sites/zafta/public/
INFO: 2014/09/29 found taxonomies: map[string]string{"category":"categories", "tag":"tags"}
WARN: 2014/09/29 Unable to locate layout: [404.html theme/404.html]
0 draft content
0 future content
2 pages created
0 tags created
0 categories created
in 4 ms
$

The output says that it created 2 pages. Those are our new posts:

$ find public -type f -name '*.html' | xargs ls -l
-rw-r--r--  1 quoha  staff  78 Sep 29 22:13 public/index.html
-rw-r--r--  1 quoha  staff   0 Sep 29 22:13 public/post/first/index.html
-rw-r--r--  1 quoha  staff   0 Sep 29 22:13 public/post/index.html
-rw-r--r--  1 quoha  staff   0 Sep 29 22:13 public/post/second/index.html
$

The new files are empty because because the templates used to generate the content are empty. The homepage doesn’t show the new content, either. We have to update the templates to add the posts.

List and Single Templates

In Hugo, we have three major kinds of templates. There’s the home page template that we updated previously. It is used only by the home page. We also have “single” templates which are used to generate output for a single content file. We also have “list” templates that are used to group multiple pieces of content before generating output.

Generally speaking, list templates are named “list.html” and single templates are named “single.html.”

There are three other types of templates: partials, content views, and terms. We will not go into much detail on these.

Add Content to the Homepage

The home page will contain a list of posts. Let’s update its template to add the posts that we just created. The logic in the template will run every time we build the site.

$ vi themes/zafta/layouts/index.html
<!DOCTYPE html>
<html>
<body>
  {{ range first 10 .Data.Pages }}
    <h1>{{ .Title }}</h1>
  {{ end }}
</body>
</html>
:wq

$

Hugo uses the Go template engine. That engine scans the template files for commands which are enclosed between “{{” and “}}”. In our template, the commands are:

range
.Title
end

The “range” command is an iterator. We’re going to use it to go through the first ten pages. Every HTML file that Hugo creates is treated as a page, so looping through the list of pages will look at every file that will be created.

The “.Title” command prints the value of the “title” variable. Hugo pulls it from the front matter in the Markdown file.

The “end” command signals the end of the range iterator. The engine loops back to the top of the iteration when it finds “end.” Everything between the “range” and “end” is evaluated every time the engine goes through the iteration. In this file, that would cause the title from the first ten pages to be output as heading level one.

It’s helpful to remember that some variables, like .Data, are created before any output files. Hugo loads every content file into the variable and then gives the template a chance to process before creating the HTML files.

Build the web site and then verify the results.

$ rm -rf public
$ hugo --verbose
INFO: 2014/09/29 Using config file: /Users/quoha/Sites/zafta/config.toml
INFO: 2014/09/29 syncing from /Users/quoha/Sites/zafta/themes/zafta/static/ to /Users/quoha/Sites/zafta/public/
INFO: 2014/09/29 syncing from /Users/quoha/Sites/zafta/static/ to /Users/quoha/Sites/zafta/public/
INFO: 2014/09/29 found taxonomies: map[string]string{"tag":"tags", "category":"categories"}
WARN: 2014/09/29 Unable to locate layout: [404.html theme/404.html]
0 draft content
0 future content
2 pages created
0 tags created
0 categories created
in 4 ms
$ find public -type f -name '*.html' | xargs ls -l
-rw-r--r--  1 quoha  staff  94 Sep 29 22:23 public/index.html
-rw-r--r--  1 quoha  staff   0 Sep 29 22:23 public/post/first/index.html
-rw-r--r--  1 quoha  staff   0 Sep 29 22:23 public/post/index.html
-rw-r--r--  1 quoha  staff   0 Sep 29 22:23 public/post/second/index.html
$ cat public/index.html
<!DOCTYPE html>
<html>
<body>
 
    <h1>second</h1>
 
    <h1>first</h1>
 
</body>
</html>
$

Congratulations, the home page shows the title of the two posts. The posts themselves are still empty, but let’s take a moment to appreciate what we’ve done. Your template now generates output dynamically. Believe it or not, by inserting the range command inside of those curly braces, you’ve learned everything you need to know to build a theme. All that’s really left is understanding which template will be used to generate each content file and becoming familiar with the commands for the template engine.

And, if that were entirely true, this tutorial would be much shorter. There are a few things to know that will make creating a new template much easier. Don’t worry, though, that’s all to come.

Add Content to the Posts

We’re working with posts, which are in the content/post/ directory. That means that their section is “post” (and if we don’t do something weird, their type is also “post”).

Hugo uses the section and type to find the template file for every piece of content. Hugo will first look for a template file that matches the section or type name. If it can’t find one, then it will look in the _default/ directory. There are some twists that we’ll cover when we get to categories and tags, but for now we can assume that Hugo will try post/single.html, then _default/single.html.

Now that we know the search rule, let’s see what we actually have available:

$ find themes/zafta -name single.html | xargs ls -l
-rw-r--r--  1 quoha  staff  132 Sep 29 17:31 themes/zafta/layouts/_default/single.html

We could create a new template, post/single.html, or change the default. Since we don’t know of any other content types, let’s start with updating the default.

Remember, any content that we haven’t created a template for will end up using this template. That can be good or bad. Bad because I know that we’re going to be adding different types of content and we’re going to end up undoing some of the changes we’ve made. It’s good because we’ll be able to see immediate results. It’s also good to start here because we can start to build the basic layout for the site. As we add more content types, we’ll refactor this file and move logic around. Hugo makes that fairly painless, so we’ll accept the cost and proceed.

Please see the Hugo documentation on template rendering for all the details on determining which template to use. And, as the docs mention, if you’re building a single page application (SPA) web site, you can delete all of the other templates and work with just the default single page. That’s a refreshing amount of joy right there.

Update the Template File

$ vi themes/zafta/layouts/_default/single.html
<!DOCTYPE html>
<html>
<head>
  <title>{{ .Title }}</title>
</head>
<body>
  <h1>{{ .Title }}</h1>
  {{ .Content }}
</body>
</html>
:wq

$

Build the web site and verify the results.

$ rm -rf public
$ hugo --verbose
INFO: 2014/09/29 Using config file: /Users/quoha/Sites/zafta/config.toml
INFO: 2014/09/29 syncing from /Users/quoha/Sites/zafta/themes/zafta/static/ to /Users/quoha/Sites/zafta/public/
INFO: 2014/09/29 syncing from /Users/quoha/Sites/zafta/static/ to /Users/quoha/Sites/zafta/public/
INFO: 2014/09/29 found taxonomies: map[string]string{"tag":"tags", "category":"categories"}
WARN: 2014/09/29 Unable to locate layout: [404.html theme/404.html]
0 draft content
0 future content
2 pages created
0 tags created
0 categories created
in 4 ms

$ find public -type f -name '*.html' | xargs ls -l
-rw-r--r--  1 quoha  staff   94 Sep 29 22:40 public/index.html
-rw-r--r--  1 quoha  staff  125 Sep 29 22:40 public/post/first/index.html
-rw-r--r--  1 quoha  staff    0 Sep 29 22:40 public/post/index.html
-rw-r--r--  1 quoha  staff  128 Sep 29 22:40 public/post/second/index.html

$ cat public/post/first/index.html
<!DOCTYPE html>
<html>
<head>
  <title>first</title>
</head>
<body>
  <h1>first</h1>
  <p>my first post</p>

</body>
</html>

$ cat public/post/second/index.html
<!DOCTYPE html>
<html>
<head>
  <title>second</title>
</head>
<body>
  <h1>second</h1>
  <p>my second post</p>

</body>
</html>
$

Notice that the posts now have content. You can go to localhost:1313/post/first to verify.

Linking to Content

The posts are on the home page. Let’s add a link from there to the post. Since this is the home page, we’ll update its template.

$ vi themes/zafta/layouts/index.html
<!DOCTYPE html>
<html>
<body>
  {{ range first 10 .Data.Pages }}
    <h1><a href="{{ .Permalink }}">{{ .Title }}</a></h1>
  {{ end }}
</body>
</html>

Build the web site and verify the results.

$ rm -rf public
$ hugo --verbose
INFO: 2014/09/29 Using config file: /Users/quoha/Sites/zafta/config.toml
INFO: 2014/09/29 syncing from /Users/quoha/Sites/zafta/themes/zafta/static/ to /Users/quoha/Sites/zafta/public/
INFO: 2014/09/29 syncing from /Users/quoha/Sites/zafta/static/ to /Users/quoha/Sites/zafta/public/
INFO: 2014/09/29 found taxonomies: map[string]string{"tag":"tags", "category":"categories"}
WARN: 2014/09/29 Unable to locate layout: [404.html theme/404.html]
0 draft content
0 future content
2 pages created
0 tags created
0 categories created
in 4 ms

$ find public -type f -name '*.html' | xargs ls -l
-rw-r--r--  1 quoha  staff  149 Sep 29 22:44 public/index.html
-rw-r--r--  1 quoha  staff  125 Sep 29 22:44 public/post/first/index.html
-rw-r--r--  1 quoha  staff    0 Sep 29 22:44 public/post/index.html
-rw-r--r--  1 quoha  staff  128 Sep 29 22:44 public/post/second/index.html

$ cat public/index.html
<!DOCTYPE html>
<html>
<body>
 
    <h1><a href="/post/second/">second</a></h1>
 
    <h1><a href="/post/first/">first</a></h1>
 
</body>
</html>

$

Create a Post Listing

We have the posts displaying on the home page and on their own page. We also have a file public/post/index.html that is empty. Let’s make it show a list of all posts (not just the first ten).

We need to decide which template to update. This will be a listing, so it should be a list template. Let’s take a quick look and see which list templates are available.

$ find themes/zafta -name list.html | xargs ls -l
-rw-r--r--  1 quoha  staff  0 Sep 29 17:31 themes/zafta/layouts/_default/list.html

As with the single post, we have to decide to update _default/list.html or create post/list.html. We still don’t have multiple content types, so let’s stay consistent and update the default list template.

Creating Top Level Pages

Let’s add an “about” page and display it at the top level (as opposed to a sub-level like we did with posts).

The default in Hugo is to use the directory structure of the content/ directory to guide the location of the generated html in the public/ directory. Let’s verify that by creating an “about” page at the top level:

$ vi content/about.md
+++
title = "about"
description = "about this site"
date = "2014-09-27"
slug = "about time"
+++

## about us

i'm speechless
:wq

Generate the web site and verify the results.

$ find public -name '*.html' | xargs ls -l
-rw-rw-r--  1 mdhender  staff   334 Sep 27 15:08 public/about-time/index.html
-rw-rw-r--  1 mdhender  staff   527 Sep 27 15:08 public/index.html
-rw-rw-r--  1 mdhender  staff   358 Sep 27 15:08 public/post/first-post/index.html
-rw-rw-r--  1 mdhender  staff     0 Sep 27 15:08 public/post/index.html
-rw-rw-r--  1 mdhender  staff   342 Sep 27 15:08 public/post/second-post/index.html

Notice that the page wasn’t created at the top level. It was created in a sub-directory named ‘about-time/’. That name came from our slug. Hugo will use the slug to name the generated content. It’s a reasonable default, by the way, but we can learn a few things by fighting it for this file.

One other thing. Take a look at the home page.

$ cat public/index.html
<!DOCTYPE html>
<html>
<body>
    <h1><a href="http://localhost:1313/post/theme/">creating a new theme</a></h1>
    <h1><a href="http://localhost:1313/about-time/">about</a></h1>
    <h1><a href="http://localhost:1313/post/second-post/">second</a></h1>
    <h1><a href="http://localhost:1313/post/first-post/">first</a></h1>
<script>document.write('<script src="http://'
        + (location.host || 'localhost').split(':')[0]
		+ ':1313/livereload.js?mindelay=10"></'
        + 'script>')</script></body>
</html>

Notice that the “about” link is listed with the posts? That’s not desirable, so let’s change that first.

$ vi themes/zafta/layouts/index.html
<!DOCTYPE html>
<html>
<body>
  <h1>posts</h1>
  {{ range first 10 .Data.Pages }}
    {{ if eq .Type "post"}}
      <h2><a href="{{ .Permalink }}">{{ .Title }}</a></h2>
    {{ end }}
  {{ end }}

  <h1>pages</h1>
  {{ range .Data.Pages }}
    {{ if eq .Type "page" }}
      <h2><a href="{{ .Permalink }}">{{ .Title }}</a></h2>
    {{ end }}
  {{ end }}
</body>
</html>
:wq

Generate the web site and verify the results. The home page has two sections, posts and pages, and each section has the right set of headings and links in it.

But, that about page still renders to about-time/index.html.

$ find public -name '*.html' | xargs ls -l
-rw-rw-r--  1 mdhender  staff    334 Sep 27 15:33 public/about-time/index.html
-rw-rw-r--  1 mdhender  staff    645 Sep 27 15:33 public/index.html
-rw-rw-r--  1 mdhender  staff    358 Sep 27 15:33 public/post/first-post/index.html
-rw-rw-r--  1 mdhender  staff      0 Sep 27 15:33 public/post/index.html
-rw-rw-r--  1 mdhender  staff    342 Sep 27 15:33 public/post/second-post/index.html

Knowing that hugo is using the slug to generate the file name, the simplest solution is to change the slug. Let’s do it the hard way and change the permalink in the configuration file.

$ vi config.toml
[permalinks]
	page = "/:title/"
	about = "/:filename/"

Generate the web site and verify that this didn’t work. Hugo lets “slug” or “URL” override the permalinks setting in the configuration file. Go ahead and comment out the slug in content/about.md, then generate the web site to get it to be created in the right place.

If you’ve been following along, you probably noticed that posts have titles in the browser and the home page doesn’t. That’s because we didn’t put the title in the home page’s template (layouts/index.html). That’s an easy thing to do, but let’s look at a different option.

We can put the common bits into a shared template that’s stored in the themes/zafta/layouts/partials/ directory.

Create the Header and Footer Partials

In Hugo, a partial is a sugar-coated template. Normally a template reference has a path specified. Partials are different. Hugo searches for them along a TODO defined search path. This makes it easier for end-users to override the theme’s presentation.

$ vi themes/zafta/layouts/partials/header.html
<!DOCTYPE html>
<html>
<head>
	<title>{{ .Title }}</title>
</head>
<body>
:wq

$ vi themes/zafta/layouts/partials/footer.html
</body>
</html>
:wq

Update the Home Page Template to Use the Partials

The most noticeable difference between a template call and a partials call is the lack of path:

{{ template "theme/partials/header.html" . }}

versus

{{ partial "header.html" . }}

Both pass in the context.

Let’s change the home page template to use these new partials.

$ vi themes/zafta/layouts/index.html
{{ partial "header.html" . }}

  <h1>posts</h1>
  {{ range first 10 .Data.Pages }}
    {{ if eq .Type "post"}}
      <h2><a href="{{ .Permalink }}">{{ .Title }}</a></h2>
    {{ end }}
  {{ end }}

  <h1>pages</h1>
  {{ range .Data.Pages }}
    {{ if or (eq .Type "page") (eq .Type "about") }}
      <h2><a href="{{ .Permalink }}">{{ .Type }} - {{ .Title }} - {{ .RelPermalink }}</a></h2>
    {{ end }}
  {{ end }}

{{ partial "footer.html" . }}
:wq

Generate the web site and verify the results. The title on the home page is now “your title here”, which comes from the “title” variable in the config.toml file.

Update the Default Single Template to Use the Partials

$ vi themes/zafta/layouts/_default/single.html
{{ partial "header.html" . }}

  <h1>{{ .Title }}</h1>
  {{ .Content }}

{{ partial "footer.html" . }}
:wq

Generate the web site and verify the results. The title on the posts and the about page should both reflect the value in the markdown file.

Add “Date Published” to Posts

It’s common to have posts display the date that they were written or published, so let’s add that. The front matter of our posts has a variable named “date.” It’s usually the date the content was created, but let’s pretend that’s the value we want to display.

Add “Date Published” to the Template

We’ll start by updating the template used to render the posts. The template code will look like:

{{ .Date.Format "Mon, Jan 2, 2006" }}

Posts use the default single template, so we’ll change that file.

$ vi themes/zafta/layouts/_default/single.html
{{ partial "header.html" . }}

  <h1>{{ .Title }}</h1>
  <h2>{{ .Date.Format "Mon, Jan 2, 2006" }}</h2>
  {{ .Content }}

{{ partial "footer.html" . }}
:wq

Generate the web site and verify the results. The posts now have the date displayed in them. There’s a problem, though. The “about” page also has the date displayed.

As usual, there are a couple of ways to make the date display only on posts. We could do an “if” statement like we did on the home page. Another way would be to create a separate template for posts.

The “if” solution works for sites that have just a couple of content types. It aligns with the principle of “code for today,” too.

Let’s assume, though, that we’ve made our site so complex that we feel we have to create a new template type. In Hugo-speak, we’re going to create a section template.

Let’s restore the default single template before we forget.

$ mkdir themes/zafta/layouts/post
$ vi themes/zafta/layouts/_default/single.html
{{ partial "header.html" . }}

  <h1>{{ .Title }}</h1>
  {{ .Content }}

{{ partial "footer.html" . }}
:wq

Now we’ll update the post’s version of the single template. If you remember Hugo’s rules, the template engine will use this version over the default.

$ vi themes/zafta/layouts/post/single.html
{{ partial "header.html" . }}

  <h1>{{ .Title }}</h1>
  <h2>{{ .Date.Format "Mon, Jan 2, 2006" }}</h2>
  {{ .Content }}

{{ partial "footer.html" . }}
:wq

Note that we removed the date logic from the default template and put it in the post template. Generate the web site and verify the results. Posts have dates and the about page doesn’t.

Don’t Repeat Yourself

DRY is a good design goal and Hugo does a great job supporting it. Part of the art of a good template is knowing when to add a new template and when to update an existing one. While you’re figuring that out, accept that you’ll be doing some refactoring. Hugo makes that easy and fast, so it’s okay to delay splitting up a template.

Creating a New Theme

Sun, 28 Sep 2014 00:00:00 +0000

Introduction

Here’s an example:

## this is a comment
$ echo this is a command
this is a command

## edit the file
$vi foo.md
+++
date = "2014-09-28"
title = "creating a new theme"
+++

bah and humbug
:wq

## show it
$ cat foo.md
+++
date = "2014-09-28"
title = "creating a new theme"
+++

bah and humbug
$

Some Definitions

There are a few concepts that you need to understand before creating a theme.

Skins

The rest of this tutorial will call a skin created in the themes/ directory a theme.

The Home Page

Site Configuration File

Content

Front Matter

The information in the front matter is passed into the template before the content is rendered into HTML.

Markdown

Content is written in Markdown which makes it easier to create the content. Hugo runs the content through a Markdown engine to create the HTML which will be written to the output file.

Template Files

There are three types of templates: single, list, and partial. Each type takes a bit of content as input and transforms it based on the commands in the template.

Please note that you can use the front matter to influence Hugo’s choice of templates.

Single Template

A single template is used to render a single piece of content. For example, an article or post would be a single piece of content and use a single template.

List Template

A list template renders a group of related content. That could be a summary of recent postings or all articles in a category. List templates can contain multiple groups.

The homepage template is a special type of list template. Hugo assumes that the home page of your site will act as the portal for the rest of the content in the site.

Partial Template

Create a New Site

Let’s use Hugo to create a new web site. I’m a Mac user, so I’ll create mine in my home directory, in the Sites folder. If you’re using Linux, you might have to create the folder first.

The “new site” command will create a skeleton of a site. It will give you the basic directory structure and a useable configuration file.

$ hugo new site ~/Sites/zafta
$ cd ~/Sites/zafta
$ ls -l
total 8
drwxr-xr-x  7 quoha  staff  238 Sep 29 16:49 .
drwxr-xr-x  3 quoha  staff  102 Sep 29 16:49 ..
drwxr-xr-x  2 quoha  staff   68 Sep 29 16:49 archetypes
-rw-r--r--  1 quoha  staff   82 Sep 29 16:49 config.toml
drwxr-xr-x  2 quoha  staff   68 Sep 29 16:49 content
drwxr-xr-x  2 quoha  staff   68 Sep 29 16:49 layouts
drwxr-xr-x  2 quoha  staff   68 Sep 29 16:49 static
$

Take a look in the content/ directory to confirm that it is empty.

The other directories (archetypes/, layouts/, and static/) are used when customizing a theme. That’s a topic for a different tutorial, so please ignore them for now.

Generate the HTML For the New Site

$ hugo --verbose
INFO: 2014/09/29 Using config file: config.toml
INFO: 2014/09/29 syncing from /Users/quoha/Sites/zafta/static/ to /Users/quoha/Sites/zafta/public/
WARN: 2014/09/29 Unable to locate layout: [index.html _default/list.html _default/single.html]
WARN: 2014/09/29 Unable to locate layout: [404.html]
0 draft content
0 future content
0 pages created
0 tags created
0 categories created
in 2 ms
$

We can verify that the command worked by looking at the directory again.

$ ls -l
total 8
drwxr-xr-x  2 quoha  staff   68 Sep 29 16:49 archetypes
-rw-r--r--  1 quoha  staff   82 Sep 29 16:49 config.toml
drwxr-xr-x  2 quoha  staff   68 Sep 29 16:49 content
drwxr-xr-x  2 quoha  staff   68 Sep 29 16:49 layouts
drwxr-xr-x  4 quoha  staff  136 Sep 29 17:02 public
drwxr-xr-x  2 quoha  staff   68 Sep 29 16:49 static
$

$ ls -l public
total 16
-rw-r--r--  1 quoha  staff  416 Sep 29 17:02 index.xml
-rw-r--r--  1 quoha  staff  262 Sep 29 17:02 sitemap.xml
$

Hugo created two XML files, which is standard, but there are no HTML files.

Test the New Site

$ hugo server --verbose
INFO: 2014/09/29 Using config file: /Users/quoha/Sites/zafta/config.toml
INFO: 2014/09/29 syncing from /Users/quoha/Sites/zafta/static/ to /Users/quoha/Sites/zafta/public/
WARN: 2014/09/29 Unable to locate layout: [index.html _default/list.html _default/single.html]
WARN: 2014/09/29 Unable to locate layout: [404.html]
0 draft content
0 future content
0 pages created
0 tags created
0 categories created
in 2 ms
Serving pages from /Users/quoha/Sites/zafta/public
Web Server is available at http://localhost:1313
Press Ctrl+C to stop

Connect to the listed URL (it’s on the line that starts with “Web Server”). If everything is working correctly, you should get a page that shows the following:

index.xml
sitemap.xml

Let’s go back and look at those warnings again.

WARN: 2014/09/29 Unable to locate layout: [index.html _default/list.html _default/single.html]
WARN: 2014/09/29 Unable to locate layout: [404.html]

That second warning is easier to explain. We haven’t created a template to be used to generate “page not found errors.” The 404 message is a topic for a separate tutorial.

Now for the first warning. It is for the home page. You can tell because the first layout that it looked for was “index.html.” That’s only used by the home page.

At this point, you’ve got a working installation and site that we can build upon. All that’s left is to add some content and a theme to display it.

Create a New Theme

Hugo doesn’t ship with a default theme. There are a few available (I counted a dozen when I first installed Hugo) and Hugo comes with a command to create new themes.

Create a Skeleton

Use the hugo “new” command to create the skeleton of a theme. This creates the directory structure and places empty files for you to fill out.

$ hugo new theme zafta

$ ls -l
total 8
drwxr-xr-x  2 quoha  staff   68 Sep 29 16:49 archetypes
-rw-r--r--  1 quoha  staff   82 Sep 29 16:49 config.toml
drwxr-xr-x  2 quoha  staff   68 Sep 29 16:49 content
drwxr-xr-x  2 quoha  staff   68 Sep 29 16:49 layouts
drwxr-xr-x  4 quoha  staff  136 Sep 29 17:02 public
drwxr-xr-x  2 quoha  staff   68 Sep 29 16:49 static
drwxr-xr-x  3 quoha  staff  102 Sep 29 17:31 themes

$ find themes -type f | xargs ls -l
-rw-r--r--  1 quoha  staff  1081 Sep 29 17:31 themes/zafta/LICENSE.md
-rw-r--r--  1 quoha  staff     0 Sep 29 17:31 themes/zafta/archetypes/default.md
-rw-r--r--  1 quoha  staff     0 Sep 29 17:31 themes/zafta/layouts/_default/list.html
-rw-r--r--  1 quoha  staff     0 Sep 29 17:31 themes/zafta/layouts/_default/single.html
-rw-r--r--  1 quoha  staff     0 Sep 29 17:31 themes/zafta/layouts/index.html
-rw-r--r--  1 quoha  staff     0 Sep 29 17:31 themes/zafta/layouts/partials/footer.html
-rw-r--r--  1 quoha  staff     0 Sep 29 17:31 themes/zafta/layouts/partials/header.html
-rw-r--r--  1 quoha  staff    93 Sep 29 17:31 themes/zafta/theme.toml
$

The skeleton includes templates (the files ending in .html), license file, a description of your theme (the theme.toml file), and an empty archetype.

$ vi themes/zafta/theme.toml
author = "michael d henderson"
description = "a minimal working template"
license = "MIT"
name = "zafta"
source_repo = ""
tags = ["tags", "categories"]
:wq

## also edit themes/zafta/LICENSE.md and change
## the bit that says "YOUR_NAME_HERE"

Note that the the skeleton’s template files are empty. Don’t worry, we’ll be changing that shortly.

$ find themes/zafta -name '*.html' | xargs ls -l
-rw-r--r--  1 quoha  staff  0 Sep 29 17:31 themes/zafta/layouts/_default/list.html
-rw-r--r--  1 quoha  staff  0 Sep 29 17:31 themes/zafta/layouts/_default/single.html
-rw-r--r--  1 quoha  staff  0 Sep 29 17:31 themes/zafta/layouts/index.html
-rw-r--r--  1 quoha  staff  0 Sep 29 17:31 themes/zafta/layouts/partials/footer.html
-rw-r--r--  1 quoha  staff  0 Sep 29 17:31 themes/zafta/layouts/partials/header.html
$

Update the Configuration File to Use the Theme

Edit the file to add the theme, add a title for the site, and specify that all of our content will use the TOML format.

$ vi config.toml
theme = "zafta"
baseurl = ""
languageCode = "en-us"
title = "zafta - totally refreshing"
MetaDataFormat = "toml"
:wq

$

Generate the Site

Now that we have an empty theme, let’s generate the site again.

$ hugo --verbose
INFO: 2014/09/29 Using config file: /Users/quoha/Sites/zafta/config.toml
INFO: 2014/09/29 syncing from /Users/quoha/Sites/zafta/themes/zafta/static/ to /Users/quoha/Sites/zafta/public/
INFO: 2014/09/29 syncing from /Users/quoha/Sites/zafta/static/ to /Users/quoha/Sites/zafta/public/
WARN: 2014/09/29 Unable to locate layout: [404.html theme/404.html]
0 draft content
0 future content
0 pages created
0 tags created
0 categories created
in 2 ms
$

Did you notice that the output is different? The warning message for the home page has disappeared and we have an additional information line saying that Hugo is syncing from the theme’s directory.

Let’s check the public/ directory to see what Hugo’s created.

$ ls -l public
total 16
drwxr-xr-x  2 quoha  staff   68 Sep 29 17:56 css
-rw-r--r--  1 quoha  staff    0 Sep 29 17:56 index.html
-rw-r--r--  1 quoha  staff  407 Sep 29 17:56 index.xml
drwxr-xr-x  2 quoha  staff   68 Sep 29 17:56 js
-rw-r--r--  1 quoha  staff  243 Sep 29 17:56 sitemap.xml
$

Notice four things:

Hugo created a home page. This is the file public/index.html.
Hugo created a css/ directory.
Hugo created a js/ directory.
Hugo claimed that it created 0 pages. It created a file and copied over static files, but didn’t create any pages. That’s because it considers a “page” to be a file created directly from a content file. It doesn’t count things like the index.html files that it creates automatically.

The Home Page

WARN: 2014/09/29 Unable to locate layout: [index.html _default/list.html _default/single.html]

If it can’t find any of these, it completely skips creating the home page. We noticed that when we built the site without having a theme installed.

$ find . -name index.html | xargs ls -l
-rw-r--r--  1 quoha  staff  0 Sep 29 20:21 ./public/index.html
-rw-r--r--  1 quoha  staff  0 Sep 29 17:31 ./themes/zafta/layouts/index.html
$

The Magic of Static

Hugo assumes that your site will use both CSS and JavaScript, so it creates directories in your theme to hold them. Remember opinions? Well, Hugo’s opinion is that you’ll store your CSS in a directory named css/ and your JavaScript in a directory named js/. If you don’t like that, you can change the directory names in your theme directory or even delete them completely. Hugo’s nice enough to offer its opinion, then behave nicely if you disagree.

$ find themes/zafta -type d | xargs ls -ld
drwxr-xr-x  7 quoha  staff  238 Sep 29 17:38 themes/zafta
drwxr-xr-x  3 quoha  staff  102 Sep 29 17:31 themes/zafta/archetypes
drwxr-xr-x  5 quoha  staff  170 Sep 29 17:31 themes/zafta/layouts
drwxr-xr-x  4 quoha  staff  136 Sep 29 17:31 themes/zafta/layouts/_default
drwxr-xr-x  4 quoha  staff  136 Sep 29 17:31 themes/zafta/layouts/partials
drwxr-xr-x  4 quoha  staff  136 Sep 29 17:31 themes/zafta/static
drwxr-xr-x  2 quoha  staff   68 Sep 29 17:31 themes/zafta/static/css
drwxr-xr-x  2 quoha  staff   68 Sep 29 17:31 themes/zafta/static/js
$

The Theme Development Cycle

When you’re working on a theme, you will make changes in the theme’s directory, rebuild the site, and check your changes in the browser. Hugo makes this very easy:

Purge the public/ directory.
Run the built in web server in watch mode.
Open your site in a browser.
Update the theme.
Glance at your browser window to see changes.
Return to step 4.

Check the main Hugo site for information on using Git with Hugo.

Purge the public/ Directory

Note: If you’re building on an SSD, you should ignore this. Churning on a SSD can be costly.

Hugo’s Watch Option

Hugo’s “--watch” option will monitor the content/ and your theme directories for changes and rebuild the site automatically.

Live Reload

Development Commands

Use the following commands as the basis for your workflow.

## purge old files. hugo will recreate the public directory.
##
$ rm -rf public
##
## run hugo in watch mode
##
$ hugo server --watch --verbose

Here’s sample output showing Hugo detecting a change to the template for the home page. Once generated, the web browser automatically reloaded the page. I’ve said this before, it’s amazing.

$ rm -rf public
$ hugo server --watch --verbose
INFO: 2014/09/29 Using config file: /Users/quoha/Sites/zafta/config.toml
INFO: 2014/09/29 syncing from /Users/quoha/Sites/zafta/themes/zafta/static/ to /Users/quoha/Sites/zafta/public/
INFO: 2014/09/29 syncing from /Users/quoha/Sites/zafta/static/ to /Users/quoha/Sites/zafta/public/
WARN: 2014/09/29 Unable to locate layout: [404.html theme/404.html]
0 draft content
0 future content
0 pages created
0 tags created
0 categories created
in 2 ms
Watching for changes in /Users/quoha/Sites/zafta/content
Serving pages from /Users/quoha/Sites/zafta/public
Web Server is available at http://localhost:1313
Press Ctrl+C to stop
INFO: 2014/09/29 File System Event: ["/Users/quoha/Sites/zafta/themes/zafta/layouts/index.html": MODIFY|ATTRIB]
Change detected, rebuilding site

WARN: 2014/09/29 Unable to locate layout: [404.html theme/404.html]
0 draft content
0 future content
0 pages created
0 tags created
0 categories created
in 1 ms

Update the Home Page Template

The home page is one of a few special pages that Hugo creates automatically. As mentioned earlier, it looks for one of three files in the theme’s layout/ directory:

index.html
_default/list.html
_default/single.html

Make a Static Home Page

Right now, that page is empty because we don’t have any content and we don’t have any logic in the template. Let’s change that by adding some text to the template.

$ vi themes/zafta/layouts/index.html
<!DOCTYPE html>
<html>
<body>
  <p>hugo says hello!</p>
</body>
</html>
:wq

$

Build the web site and then verify the results.

$ hugo --verbose
INFO: 2014/09/29 Using config file: /Users/quoha/Sites/zafta/config.toml
INFO: 2014/09/29 syncing from /Users/quoha/Sites/zafta/themes/zafta/static/ to /Users/quoha/Sites/zafta/public/
INFO: 2014/09/29 syncing from /Users/quoha/Sites/zafta/static/ to /Users/quoha/Sites/zafta/public/
WARN: 2014/09/29 Unable to locate layout: [404.html theme/404.html]
0 draft content
0 future content
0 pages created
0 tags created
0 categories created
in 2 ms

$ find public -type f -name '*.html' | xargs ls -l
-rw-r--r--  1 quoha  staff  78 Sep 29 21:26 public/index.html

$ cat public/index.html
<!DOCTYPE html>
<html>
<body>
  <p>hugo says hello!</p>
</html>

Live Reload

Note: If you’re running the server with the --watch option, you’ll see different content in the file:

$ cat public/index.html
<!DOCTYPE html>
<html>
<body>
  <p>hugo says hello!</p>
<script>document.write('<script src="http://'
        + (location.host || 'localhost').split(':')[0]
    + ':1313/livereload.js?mindelay=10"></'
        + 'script>')</script></body>
</html>

When you use --watch, the Live Reload script is added by Hugo. Look for live reload in the documentation to see what it does and how to disable it.

Build a “Dynamic” Home Page

Create New Posts

Now that we have the home page generating static content, let’s add some content to the site. We’ll display these posts as a list on the home page and on their own page, too.

Hugo has a command to generate a skeleton post, just like it does for sites and themes.

$ hugo --verbose new post/first.md
INFO: 2014/09/29 Using config file: /Users/quoha/Sites/zafta/config.toml
INFO: 2014/09/29 attempting to create  post/first.md of post
INFO: 2014/09/29 curpath: /Users/quoha/Sites/zafta/themes/zafta/archetypes/default.md
ERROR: 2014/09/29 Unable to Cast <nil> to map[string]interface{}

$

That wasn’t very nice, was it?

$ vi themes/zafta/archetypes/post.md
+++
Description = ""
Tags = []
Categories = []
+++
:wq

$ find themes/zafta/archetypes -type f | xargs ls -l
-rw-r--r--  1 quoha  staff   0 Sep 29 21:53 themes/zafta/archetypes/default.md
-rw-r--r--  1 quoha  staff  51 Sep 29 21:54 themes/zafta/archetypes/post.md

$ hugo --verbose new post/first.md
INFO: 2014/09/29 Using config file: /Users/quoha/Sites/zafta/config.toml
INFO: 2014/09/29 attempting to create  post/first.md of post
INFO: 2014/09/29 curpath: /Users/quoha/Sites/zafta/themes/zafta/archetypes/post.md
INFO: 2014/09/29 creating /Users/quoha/Sites/zafta/content/post/first.md
/Users/quoha/Sites/zafta/content/post/first.md created

$ hugo --verbose new post/second.md
INFO: 2014/09/29 Using config file: /Users/quoha/Sites/zafta/config.toml
INFO: 2014/09/29 attempting to create  post/second.md of post
INFO: 2014/09/29 curpath: /Users/quoha/Sites/zafta/themes/zafta/archetypes/post.md
INFO: 2014/09/29 creating /Users/quoha/Sites/zafta/content/post/second.md
/Users/quoha/Sites/zafta/content/post/second.md created

$ ls -l content/post
total 16
-rw-r--r--  1 quoha  staff  104 Sep 29 21:54 first.md
-rw-r--r--  1 quoha  staff  105 Sep 29 21:57 second.md

$ cat content/post/first.md
+++
Categories = []
Description = ""
Tags = []
date = "2014-09-29T21:54:53-05:00"
title = "first"

+++
my first post

$ cat content/post/second.md
+++
Categories = []
Description = ""
Tags = []
date = "2014-09-29T21:57:09-05:00"
title = "second"

+++
my second post

$

Build the web site and then verify the results.

$ rm -rf public
$ hugo --verbose
INFO: 2014/09/29 Using config file: /Users/quoha/Sites/zafta/config.toml
INFO: 2014/09/29 syncing from /Users/quoha/Sites/zafta/themes/zafta/static/ to /Users/quoha/Sites/zafta/public/
INFO: 2014/09/29 syncing from /Users/quoha/Sites/zafta/static/ to /Users/quoha/Sites/zafta/public/
INFO: 2014/09/29 found taxonomies: map[string]string{"category":"categories", "tag":"tags"}
WARN: 2014/09/29 Unable to locate layout: [404.html theme/404.html]
0 draft content
0 future content
2 pages created
0 tags created
0 categories created
in 4 ms
$

The output says that it created 2 pages. Those are our new posts:

$ find public -type f -name '*.html' | xargs ls -l
-rw-r--r--  1 quoha  staff  78 Sep 29 22:13 public/index.html
-rw-r--r--  1 quoha  staff   0 Sep 29 22:13 public/post/first/index.html
-rw-r--r--  1 quoha  staff   0 Sep 29 22:13 public/post/index.html
-rw-r--r--  1 quoha  staff   0 Sep 29 22:13 public/post/second/index.html
$

The new files are empty because because the templates used to generate the content are empty. The homepage doesn’t show the new content, either. We have to update the templates to add the posts.

List and Single Templates

Generally speaking, list templates are named “list.html” and single templates are named “single.html.”

There are three other types of templates: partials, content views, and terms. We will not go into much detail on these.

Add Content to the Homepage

The home page will contain a list of posts. Let’s update its template to add the posts that we just created. The logic in the template will run every time we build the site.

$ vi themes/zafta/layouts/index.html
<!DOCTYPE html>
<html>
<body>
  {{ range first 10 .Data.Pages }}
    <h1>{{ .Title }}</h1>
  {{ end }}
</body>
</html>
:wq

$

Hugo uses the Go template engine. That engine scans the template files for commands which are enclosed between “{{” and “}}”. In our template, the commands are:

range
.Title
end

The “.Title” command prints the value of the “title” variable. Hugo pulls it from the front matter in the Markdown file.

Build the web site and then verify the results.

$ rm -rf public
$ hugo --verbose
INFO: 2014/09/29 Using config file: /Users/quoha/Sites/zafta/config.toml
INFO: 2014/09/29 syncing from /Users/quoha/Sites/zafta/themes/zafta/static/ to /Users/quoha/Sites/zafta/public/
INFO: 2014/09/29 syncing from /Users/quoha/Sites/zafta/static/ to /Users/quoha/Sites/zafta/public/
INFO: 2014/09/29 found taxonomies: map[string]string{"tag":"tags", "category":"categories"}
WARN: 2014/09/29 Unable to locate layout: [404.html theme/404.html]
0 draft content
0 future content
2 pages created
0 tags created
0 categories created
in 4 ms
$ find public -type f -name '*.html' | xargs ls -l
-rw-r--r--  1 quoha  staff  94 Sep 29 22:23 public/index.html
-rw-r--r--  1 quoha  staff   0 Sep 29 22:23 public/post/first/index.html
-rw-r--r--  1 quoha  staff   0 Sep 29 22:23 public/post/index.html
-rw-r--r--  1 quoha  staff   0 Sep 29 22:23 public/post/second/index.html
$ cat public/index.html
<!DOCTYPE html>
<html>
<body>

    <h1>second</h1>

    <h1>first</h1>

</body>
</html>
$

And, if that were entirely true, this tutorial would be much shorter. There are a few things to know that will make creating a new template much easier. Don’t worry, though, that’s all to come.

Add Content to the Posts

We’re working with posts, which are in the content/post/ directory. That means that their section is “post” (and if we don’t do something weird, their type is also “post”).

Now that we know the search rule, let’s see what we actually have available:

$ find themes/zafta -name single.html | xargs ls -l
-rw-r--r--  1 quoha  staff  132 Sep 29 17:31 themes/zafta/layouts/_default/single.html

We could create a new template, post/single.html, or change the default. Since we don’t know of any other content types, let’s start with updating the default.

Update the Template File

$ vi themes/zafta/layouts/_default/single.html
<!DOCTYPE html>
<html>
<head>
  <title>{{ .Title }}</title>
</head>
<body>
  <h1>{{ .Title }}</h1>
  {{ .Content }}
</body>
</html>
:wq

$

Build the web site and verify the results.

$ rm -rf public
$ hugo --verbose
INFO: 2014/09/29 Using config file: /Users/quoha/Sites/zafta/config.toml
INFO: 2014/09/29 syncing from /Users/quoha/Sites/zafta/themes/zafta/static/ to /Users/quoha/Sites/zafta/public/
INFO: 2014/09/29 syncing from /Users/quoha/Sites/zafta/static/ to /Users/quoha/Sites/zafta/public/
INFO: 2014/09/29 found taxonomies: map[string]string{"tag":"tags", "category":"categories"}
WARN: 2014/09/29 Unable to locate layout: [404.html theme/404.html]
0 draft content
0 future content
2 pages created
0 tags created
0 categories created
in 4 ms

$ find public -type f -name '*.html' | xargs ls -l
-rw-r--r--  1 quoha  staff   94 Sep 29 22:40 public/index.html
-rw-r--r--  1 quoha  staff  125 Sep 29 22:40 public/post/first/index.html
-rw-r--r--  1 quoha  staff    0 Sep 29 22:40 public/post/index.html
-rw-r--r--  1 quoha  staff  128 Sep 29 22:40 public/post/second/index.html

$ cat public/post/first/index.html
<!DOCTYPE html>
<html>
<head>
  <title>first</title>
</head>
<body>
  <h1>first</h1>
  <p>my first post</p>

</body>
</html>

$ cat public/post/second/index.html
<!DOCTYPE html>
<html>
<head>
  <title>second</title>
</head>
<body>
  <h1>second</h1>
  <p>my second post</p>

</body>
</html>
$

Notice that the posts now have content. You can go to localhost:1313/post/first to verify.

Linking to Content

The posts are on the home page. Let’s add a link from there to the post. Since this is the home page, we’ll update its template.

$ vi themes/zafta/layouts/index.html
<!DOCTYPE html>
<html>
<body>
  {{ range first 10 .Data.Pages }}
    <h1><a href="{{ .Permalink }}">{{ .Title }}</a></h1>
  {{ end }}
</body>
</html>

Build the web site and verify the results.

$ rm -rf public
$ hugo --verbose
INFO: 2014/09/29 Using config file: /Users/quoha/Sites/zafta/config.toml
INFO: 2014/09/29 syncing from /Users/quoha/Sites/zafta/themes/zafta/static/ to /Users/quoha/Sites/zafta/public/
INFO: 2014/09/29 syncing from /Users/quoha/Sites/zafta/static/ to /Users/quoha/Sites/zafta/public/
INFO: 2014/09/29 found taxonomies: map[string]string{"tag":"tags", "category":"categories"}
WARN: 2014/09/29 Unable to locate layout: [404.html theme/404.html]
0 draft content
0 future content
2 pages created
0 tags created
0 categories created
in 4 ms

$ find public -type f -name '*.html' | xargs ls -l
-rw-r--r--  1 quoha  staff  149 Sep 29 22:44 public/index.html
-rw-r--r--  1 quoha  staff  125 Sep 29 22:44 public/post/first/index.html
-rw-r--r--  1 quoha  staff    0 Sep 29 22:44 public/post/index.html
-rw-r--r--  1 quoha  staff  128 Sep 29 22:44 public/post/second/index.html

$ cat public/index.html
<!DOCTYPE html>
<html>
<body>

    <h1><a href="/post/second/">second</a></h1>

    <h1><a href="/post/first/">first</a></h1>

</body>
</html>

$

Create a Post Listing

We have the posts displaying on the home page and on their own page. We also have a file public/post/index.html that is empty. Let’s make it show a list of all posts (not just the first ten).

We need to decide which template to update. This will be a listing, so it should be a list template. Let’s take a quick look and see which list templates are available.

$ find themes/zafta -name list.html | xargs ls -l
-rw-r--r--  1 quoha  staff  0 Sep 29 17:31 themes/zafta/layouts/_default/list.html

Creating Top Level Pages

Let’s add an “about” page and display it at the top level (as opposed to a sub-level like we did with posts).

$ vi content/about.md
+++
title = "about"
description = "about this site"
date = "2014-09-27"
slug = "about time"
+++

## about us

i'm speechless
:wq

Generate the web site and verify the results.

$ find public -name '*.html' | xargs ls -l
-rw-rw-r--  1 mdhender  staff   334 Sep 27 15:08 public/about-time/index.html
-rw-rw-r--  1 mdhender  staff   527 Sep 27 15:08 public/index.html
-rw-rw-r--  1 mdhender  staff   358 Sep 27 15:08 public/post/first-post/index.html
-rw-rw-r--  1 mdhender  staff     0 Sep 27 15:08 public/post/index.html
-rw-rw-r--  1 mdhender  staff   342 Sep 27 15:08 public/post/second-post/index.html

One other thing. Take a look at the home page.

$ cat public/index.html
<!DOCTYPE html>
<html>
<body>
    <h1><a href="http://localhost:1313/post/theme/">creating a new theme</a></h1>
    <h1><a href="http://localhost:1313/about-time/">about</a></h1>
    <h1><a href="http://localhost:1313/post/second-post/">second</a></h1>
    <h1><a href="http://localhost:1313/post/first-post/">first</a></h1>
<script>document.write('<script src="http://'
        + (location.host || 'localhost').split(':')[0]
		+ ':1313/livereload.js?mindelay=10"></'
        + 'script>')</script></body>
</html>

Notice that the “about” link is listed with the posts? That’s not desirable, so let’s change that first.

$ vi themes/zafta/layouts/index.html
<!DOCTYPE html>
<html>
<body>
  <h1>posts</h1>
  {{ range first 10 .Data.Pages }}
    {{ if eq .Type "post"}}
      <h2><a href="{{ .Permalink }}">{{ .Title }}</a></h2>
    {{ end }}
  {{ end }}

  <h1>pages</h1>
  {{ range .Data.Pages }}
    {{ if eq .Type "page" }}
      <h2><a href="{{ .Permalink }}">{{ .Title }}</a></h2>
    {{ end }}
  {{ end }}
</body>
</html>
:wq

Generate the web site and verify the results. The home page has two sections, posts and pages, and each section has the right set of headings and links in it.

But, that about page still renders to about-time/index.html.

$ find public -name '*.html' | xargs ls -l
-rw-rw-r--  1 mdhender  staff    334 Sep 27 15:33 public/about-time/index.html
-rw-rw-r--  1 mdhender  staff    645 Sep 27 15:33 public/index.html
-rw-rw-r--  1 mdhender  staff    358 Sep 27 15:33 public/post/first-post/index.html
-rw-rw-r--  1 mdhender  staff      0 Sep 27 15:33 public/post/index.html
-rw-rw-r--  1 mdhender  staff    342 Sep 27 15:33 public/post/second-post/index.html

Knowing that hugo is using the slug to generate the file name, the simplest solution is to change the slug. Let’s do it the hard way and change the permalink in the configuration file.

$ vi config.toml
[permalinks]
	page = "/:title/"
	about = "/:filename/"

We can put the common bits into a shared template that’s stored in the themes/zafta/layouts/partials/ directory.

Create the Header and Footer Partials

$ vi themes/zafta/layouts/partials/header.html
<!DOCTYPE html>
<html>
<head>
	<title>{{ .Title }}</title>
</head>
<body>
:wq

$ vi themes/zafta/layouts/partials/footer.html
</body>
</html>
:wq

Update the Home Page Template to Use the Partials

The most noticeable difference between a template call and a partials call is the lack of path:

{{ template "theme/partials/header.html" . }}

versus

{{ partial "header.html" . }}

Both pass in the context.

Let’s change the home page template to use these new partials.

$ vi themes/zafta/layouts/index.html
{{ partial "header.html" . }}

  <h1>posts</h1>
  {{ range first 10 .Data.Pages }}
    {{ if eq .Type "post"}}
      <h2><a href="{{ .Permalink }}">{{ .Title }}</a></h2>
    {{ end }}
  {{ end }}

  <h1>pages</h1>
  {{ range .Data.Pages }}
    {{ if or (eq .Type "page") (eq .Type "about") }}
      <h2><a href="{{ .Permalink }}">{{ .Type }} - {{ .Title }} - {{ .RelPermalink }}</a></h2>
    {{ end }}
  {{ end }}

{{ partial "footer.html" . }}
:wq

Generate the web site and verify the results. The title on the home page is now “your title here”, which comes from the “title” variable in the config.toml file.

Update the Default Single Template to Use the Partials

$ vi themes/zafta/layouts/_default/single.html
{{ partial "header.html" . }}

  <h1>{{ .Title }}</h1>
  {{ .Content }}

{{ partial "footer.html" . }}
:wq

Generate the web site and verify the results. The title on the posts and the about page should both reflect the value in the markdown file.

Add “Date Published” to Posts

Add “Date Published” to the Template

We’ll start by updating the template used to render the posts. The template code will look like:

{{ .Date.Format "Mon, Jan 2, 2006" }}

Posts use the default single template, so we’ll change that file.

$ vi themes/zafta/layouts/_default/single.html
{{ partial "header.html" . }}

  <h1>{{ .Title }}</h1>
  <h2>{{ .Date.Format "Mon, Jan 2, 2006" }}</h2>
  {{ .Content }}

{{ partial "footer.html" . }}
:wq

Generate the web site and verify the results. The posts now have the date displayed in them. There’s a problem, though. The “about” page also has the date displayed.

The “if” solution works for sites that have just a couple of content types. It aligns with the principle of “code for today,” too.

Let’s assume, though, that we’ve made our site so complex that we feel we have to create a new template type. In Hugo-speak, we’re going to create a section template.

Let’s restore the default single template before we forget.

$ mkdir themes/zafta/layouts/post
$ vi themes/zafta/layouts/_default/single.html
{{ partial "header.html" . }}

  <h1>{{ .Title }}</h1>
  {{ .Content }}

{{ partial "footer.html" . }}
:wq

Now we’ll update the post’s version of the single template. If you remember Hugo’s rules, the template engine will use this version over the default.

$ vi themes/zafta/layouts/post/single.html
{{ partial "header.html" . }}

  <h1>{{ .Title }}</h1>
  <h2>{{ .Date.Format "Mon, Jan 2, 2006" }}</h2>
  {{ .Content }}

{{ partial "footer.html" . }}
:wq

Note that we removed the date logic from the default template and put it in the post template. Generate the web site and verify the results. Posts have dates and the about page doesn’t.

Don’t Repeat Yourself

(Hu)go Template Primer

Wed, 02 Apr 2014 00:00:00 +0000

Hugo uses the excellent go html/template library for its template engine. It is an extremely lightweight engine that provides a very small amount of logic. In our experience that it is just the right amount of logic to be able to create a good static website. If you have used other template systems from different languages or frameworks you will find a lot of similarities in go templates.

This document is a brief primer on using go templates. The go docs provide more details.

Introduction to Go Templates

Go templates provide an extremely simple template language. It adheres to the belief that only the most basic of logic belongs in the template or view layer. One consequence of this simplicity is that go templates parse very quickly.

A unique characteristic of go templates is they are content aware. Variables and content will be sanitized depending on the context of where they are used. More details can be found in the go docs.

Basic Syntax

Go lang templates are html files with the addition of variables and functions.

Go variables and functions are accessible within {{ }}

Accessing a predefined variable “foo”:

{{ foo }}

Parameters are separated using spaces

Calling the add function with input of 1, 2:

{{ add 1 2 }}

Methods and fields are accessed via dot notation

Accessing the Page Parameter “bar”

{{ .Params.bar }}

Parentheses can be used to group items together

{{ if or (isset .Params "alt") (isset .Params "caption") }} Caption {{ end }}

Variables

Each go template has a struct (object) made available to it. In hugo each template is passed either a page or a node struct depending on which type of page you are rendering. More details are available on the variables page.

A variable is accessed by referencing the variable name.

<title>{{ .Title }}</title>

Variables can also be defined and referenced.

{{ $address := "123 Main St."}}
{{ $address }}

Functions

Go template ship with a few functions which provide basic functionality. The go template system also provides a mechanism for applications to extend the available functions with their own. Hugo template functions provide some additional functionality we believe are useful for building websites. Functions are called by using their name followed by the required parameters separated by spaces. Template functions cannot be added without recompiling hugo.

Example:

{{ add 1 2 }}

Includes

When including another template you will pass to it the data it will be able to access. To pass along the current context please remember to include a trailing dot. The templates location will always be starting at the /layout/ directory within Hugo.

Example:

{{ template "chrome/header.html" . }}

Logic

Go templates provide the most basic iteration and conditional logic.

Iteration

Just like in go, the go templates make heavy use of range to iterate over a map, array or slice. The following are different examples of how to use range.

Example 1: Using Context

{{ range array }}
    {{ . }}
{{ end }}

Example 2: Declaring value variable name

{{range $element := array}}
    {{ $element }}
{{ end }}

Example 2: Declaring key and value variable name

{{range $index, $element := array}}
    {{ $index }}
    {{ $element }}
{{ end }}

Conditionals

If, else, with, or, & and provide the framework for handling conditional logic in Go Templates. Like range, each statement is closed with end.

Go Templates treat the following values as false:

false
0
any array, slice, map, or string of length zero

Example 1: If

{{ if isset .Params "title" }}<h4>{{ index .Params "title" }}</h4>{{ end }}

Example 2: If -> Else

{{ if isset .Params "alt" }}
    {{ index .Params "alt" }}
{{else}}
    {{ index .Params "caption" }}
{{ end }}

Example 3: And & Or

{{ if and (or (isset .Params "title") (isset .Params "caption")) (isset .Params "attr")}}

Example 4: With

An alternative way of writing “if” and then referencing the same value is to use “with” instead. With rebinds the context . within its scope, and skips the block if the variable is absent.

The first example above could be simplified as:

{{ with .Params.title }}<h4>{{ . }}</h4>{{ end }}

Example 5: If -> Else If

{{ if isset .Params "alt" }}
    {{ index .Params "alt" }}
{{ else if isset .Params "caption" }}
    {{ index .Params "caption" }}
{{ end }}

Pipes

One of the most powerful components of go templates is the ability to stack actions one after another. This is done by using pipes. Borrowed from unix pipes, the concept is simple, each pipeline’s output becomes the input of the following pipe.

Because of the very simple syntax of go templates, the pipe is essential to being able to chain together function calls. One limitation of the pipes is that they only can work with a single value and that value becomes the last parameter of the next pipeline.

A few simple examples should help convey how to use the pipe.

Example 1 :

{{ if eq 1 1 }} Same {{ end }}

is the same as

{{ eq 1 1 | if }} Same {{ end }}

It does look odd to place the if at the end, but it does provide a good illustration of how to use the pipes.

Example 2 :

{{ index .Params "disqus_url" | html }}

Access the page parameter called “disqus_url” and escape the HTML.

Example 3 :

{{ if or (or (isset .Params "title") (isset .Params "caption")) (isset .Params "attr")}}
Stuff Here
{{ end }}

Could be rewritten as

{{  isset .Params "caption" | or isset .Params "title" | or isset .Params "attr" | if }}
Stuff Here
{{ end }}

Context (aka. the dot)

The most easily overlooked concept to understand about go templates is that {{ . }} always refers to the current context. In the top level of your template this will be the data set made available to it. Inside of a iteration it will have the value of the current item. When inside of a loop the context has changed. . will no longer refer to the data available to the entire page. If you need to access this from within the loop you will likely want to set it to a variable instead of depending on the context.

Example:

  {{ $title := .Site.Title }}
  {{ range .Params.tags }}
    <li> <a href="{{ $baseurl }}/tags/{{ . | urlize }}">{{ . }}</a> - {{ $title }} </li>
  {{ end }}

Notice how once we have entered the loop the value of {{ . }} has changed. We have defined a variable outside of the loop so we have access to it from within the loop.

Hugo Parameters

Hugo provides the option of passing values to the template language through the site configuration (for sitewide values), or through the meta data of each specific piece of content. You can define any values of any type (supported by your front matter/config format) and use them however you want to inside of your templates.

Using Content (page) Parameters

In each piece of content you can provide variables to be used by the templates. This happens in the front matter.

An example of this is used in this documentation site. Most of the pages benefit from having the table of contents provided. Sometimes the TOC just doesn’t make a lot of sense. We’ve defined a variable in our front matter of some pages to turn off the TOC from being displayed.

Here is the example front matter:

---
title: "Permalinks"
date: "2013-11-18"
aliases:
  - "/doc/permalinks/"
groups: ["extras"]
groups_weight: 30
notoc: true
---

Here is the corresponding code inside of the template:

  {{ if not .Params.notoc }}
    <div id="toc" class="well col-md-4 col-sm-6">
    {{ .TableOfContents }}
    </div>
  {{ end }}

Using Site (config) Parameters

In your top-level configuration file (eg, config.yaml) you can define site parameters, which are values which will be available to you in chrome.

For instance, you might declare:

params:
  CopyrightHTML: "Copyright &#xA9; 2013 John Doe. All Rights Reserved."
  TwitterUser: "spf13"
  SidebarRecentLimit: 5

Within a footer layout, you might then declare a <footer> which is only provided if the CopyrightHTML parameter is provided, and if it is given, you would declare it to be HTML-safe, so that the HTML entity is not escaped again. This would let you easily update just your top-level config file each January 1st, instead of hunting through your templates.

{{if .Site.Params.CopyrightHTML}}<footer>
<div class="text-center">{{.Site.Params.CopyrightHTML | safeHtml}}</div>
</footer>{{end}}

An alternative way of writing the “if” and then referencing the same value is to use “with” instead. With rebinds the context . within its scope, and skips the block if the variable is absent:

{{with .Site.Params.TwitterUser}}<span class="twitter">
<a href="https://twitter.com/{{.}}" rel="author">
<img src="/images/twitter.png" width="48" height="48" title="Twitter: {{.}}"
 alt="Twitter"></a>
</span>{{end}}

Finally, if you want to pull “magic constants” out of your layouts, you can do so, such as in this example:

<nav class="recent">
  <h1>Recent Posts</h1>
  <ul>{{range first .Site.Params.SidebarRecentLimit .Site.Recent}}
    <li><a href="{{.RelPermalink}}">{{.Title}}</a></li>
  {{end}}</ul>
</nav>

Getting Started with Hugo

Wed, 02 Apr 2014 00:00:00 +0000

Step 1. Install Hugo

Goto hugo releases and download the appropriate version for your os and architecture.

Save it somewhere specific as we will be using it in the next step.

More complete instructions are available at installing hugo

Step 2. Build the Docs

Hugo has its own example site which happens to also be the documentation site you are reading right now.

Follow the following steps:

Clone the hugo repository
Go into the repo
Run hugo in server mode and build the docs
Open your browser to http://localhost:1313

Corresponding pseudo commands:

git clone https://github.com/spf13/hugo
cd hugo
/path/to/where/you/installed/hugo server --source=./docs
> 29 pages created
> 0 tags index created
> in 27 ms
> Web Server is available at http://localhost:1313
> Press ctrl+c to stop

Once you’ve gotten here, follow along the rest of this page on your local build.

Step 3. Change the docs site

Stop the Hugo process by hitting ctrl+c.

Now we are going to run hugo again, but this time with hugo in watch mode.

/path/to/hugo/from/step/1/hugo server --source=./docs --watch
> 29 pages created
> 0 tags index created
> in 27 ms
> Web Server is available at http://localhost:1313
> Watching for changes in /Users/spf13/Code/hugo/docs/content
> Press ctrl+c to stop

Open your favorite editor and change one of the source content pages. How about changing this very file to fix the typo. How about changing this very file to fix the typo.

Content files are found in docs/content/. Unless otherwise specified, files are located at the same relative location as the url, in our case docs/content/overview/quickstart.md.

Change and save this file.. Notice what happened in your terminal.

> Change detected, rebuilding site

> 29 pages created
> 0 tags index created
> in 26 ms

Refresh the browser and observe that the typo is now fixed.

Notice how quick that was. Try to refresh the site before it’s finished building.. I double dare you. Having nearly instant feedback enables you to have your creativity flow without waiting for long builds.

Step 4. Have fun

The best way to learn something is to play with it.

Migrate to Hugo from Jekyll

Mon, 10 Mar 2014 00:00:00 +0000

Move static content to `static`

Jekyll has a rule that any directory not starting with _ will be copied as-is to the _site output. Hugo keeps all static content under static. You should therefore move it all there. With Jekyll, something that looked like

▾ <root>/
    ▾ images/
        logo.png

should become

▾ <root>/
    ▾ static/
        ▾ images/
            logo.png

Additionally, you’ll want any files that should reside at the root (such as CNAME) to be moved to static.

Create your Hugo configuration file

Hugo can read your configuration as JSON, YAML or TOML. Hugo supports parameters custom configuration too. Refer to the Hugo configuration documentation for details.

Set your configuration publish folder to `_site`

The default is for Jekyll to publish to _site and for Hugo to publish to public. If, like me, you have _site mapped to a git submodule on the gh-pages branch, you’ll want to do one of two alternatives:

Change your submodule to point to map gh-pages to public instead of _site (recommended).

 git submodule deinit _site
 git rm _site
 git submodule add -b gh-pages git@github.com:your-username/your-repo.git public

Or, change the Hugo configuration to use _site instead of public.
```
 {
     ..
     "publishdir": "_site",
     ..
 }
```

Convert Jekyll templates to Hugo templates

That’s the bulk of the work right here. The documentation is your friend. You should refer to Jekyll’s template documentation if you need to refresh your memory on how you built your blog and Hugo’s template to learn Hugo’s way.

As a single reference data point, converting my templates for heyitsalex.net took me no more than a few hours.

Convert Jekyll plugins to Hugo shortcodes

Jekyll has plugins; Hugo has shortcodes. It’s fairly trivial to do a port.

Implementation

As an example, I was using a custom image_tag plugin to generate figures with caption when running Jekyll. As I read about shortcodes, I found Hugo had a nice built-in shortcode that does exactly the same thing.

Jekyll’s plugin:

module Jekyll
  class ImageTag < Liquid::Tag
    @url = nil
    @caption = nil
    @class = nil
    @link = nil
    // Patterns
    IMAGE_URL_WITH_CLASS_AND_CAPTION =
    IMAGE_URL_WITH_CLASS_AND_CAPTION_AND_LINK = /(\w+)(\s+)((https?:\/\/|\/)(\S+))(\s+)"(.*?)"(\s+)->((https?:\/\/|\/)(\S+))(\s*)/i
    IMAGE_URL_WITH_CAPTION = /((https?:\/\/|\/)(\S+))(\s+)"(.*?)"/i
    IMAGE_URL_WITH_CLASS = /(\w+)(\s+)((https?:\/\/|\/)(\S+))/i
    IMAGE_URL = /((https?:\/\/|\/)(\S+))/i
    def initialize(tag_name, markup, tokens)
      super
      if markup =~ IMAGE_URL_WITH_CLASS_AND_CAPTION_AND_LINK
        @class   = $1
        @url     = $3
        @caption = $7
        @link = $9
      elsif markup =~ IMAGE_URL_WITH_CLASS_AND_CAPTION
        @class   = $1
        @url     = $3
        @caption = $7
      elsif markup =~ IMAGE_URL_WITH_CAPTION
        @url     = $1
        @caption = $5
      elsif markup =~ IMAGE_URL_WITH_CLASS
        @class = $1
        @url   = $3
      elsif markup =~ IMAGE_URL
        @url = $1
      end
    end
    def render(context)
      if @class
        source = "<figure class='#{@class}'>"
      else
        source = "<figure>"
      end
      if @link
        source += "<a href=\"#{@link}\">"
      end
      source += "<img src=\"#{@url}\">"
      if @link
        source += "</a>"
      end
      source += "<figcaption>#{@caption}</figcaption>" if @caption
      source += "</figure>"
      source
    end
  end
end
Liquid::Template.register_tag('image', Jekyll::ImageTag)

is written as this Hugo shortcode:

<!-- image -->
<figure {{ with .Get "class" }}class="{{.}}"{{ end }}>
    {{ with .Get "link"}}<a href="{{.}}">{{ end }}
        <img src="{{ .Get "src" }}" {{ if or (.Get "alt") (.Get "caption") }}alt="{{ with .Get "alt"}}{{.}}{{else}}{{ .Get "caption" }}{{ end }}"{{ end }} />
    {{ if .Get "link"}}</a>{{ end }}
    {{ if or (or (.Get "title") (.Get "caption")) (.Get "attr")}}
    <figcaption>{{ if isset .Params "title" }}
        {{ .Get "title" }}{{ end }}
        {{ if or (.Get "caption") (.Get "attr")}}<p>
        {{ .Get "caption" }}
        {{ with .Get "attrlink"}}<a href="{{.}}"> {{ end }}
            {{ .Get "attr" }}
        {{ if .Get "attrlink"}}</a> {{ end }}
        </p> {{ end }}
    </figcaption>
    {{ end }}
</figure>
<!-- image -->

Usage

I simply changed:

{% image full http://farm5.staticflickr.com/4136/4829260124_57712e570a_o_d.jpg "One of my favorite touristy-type photos. I secretly waited for the good light while we were "having fun" and took this. Only regret: a stupid pole in the top-left corner of the frame I had to clumsily get rid of at post-processing." ->http://www.flickr.com/photos/alexnormand/4829260124/in/set-72157624547713078/ %}

to this (this example uses a slightly extended version named fig, different than the built-in figure):

{{% fig class="full" src="http://farm5.staticflickr.com/4136/4829260124_57712e570a_o_d.jpg" title="One of my favorite touristy-type photos. I secretly waited for the good light while we were having fun and took this. Only regret: a stupid pole in the top-left corner of the frame I had to clumsily get rid of at post-processing." link="http://www.flickr.com/photos/alexnormand/4829260124/in/set-72157624547713078/" %}}

As a bonus, the shortcode named parameters are, arguably, more readable.

Finishing touches

Fix content

Depending on the amount of customization that was done with each post with Jekyll, this step will require more or less effort. There are no hard and fast rules here except that hugo server --watch is your friend. Test your changes and fix errors as needed.

Clean up

You’ll want to remove the Jekyll configuration at this point. If you have anything else that isn’t used, delete it.

A practical example in a diff

Hey, it’s Alex was migrated in less than a father-with-kids day from Jekyll to Hugo. You can see all the changes (and screw-ups) by looking at this diff.