Eleventy plugin for content dates

Static site generator Eleventy uses a special data field date with predefined values Created, Last Modified, git Created, git Last Modified to sort collections and show post date.

But there are two problems here:

• it is not possible to use several fields at the same time, for example, for the creation date and for the modification date,
• the date is calculated for one file, but you can have a whole folder for an article with pictures, fonts and other resources. Their update should also be considered as a modification of the article.

This plugin solves this problems.

Installation

npm install @web-alchemy/eleventy-plugin-content-dates

Configuration

const { eleventyPluginContentDates } = require('@web-alchemy/eleventy-plugin-content-dates');

module.exports = function(eleventyConfig) {
  eleventyConfig.addPlugin(eleventyPluginContentDates);
}

By default, dates are calculated for a file with the path data.page.inputPath. But you can change the path to the entity for which you need to calculate dates, for example, for a folder. Sometimes you need to calculate dates for folders, as they may contain other resources, for example, pictures. You can use the getContentFolderPath function from the plugin or write your own.

const { eleventyPluginContentDates, getContentFolderPath } = require('@web-alchemy/eleventy-plugin-content-dates');

module.exports = function(eleventyConfig) {
  eleventyConfig.addPlugin(eleventyPluginContentDates, {
    // this is default
    getContentPath: (data) => {
      return data.page.inputPath;
    }
    
    // you can compute dates for folders using library function `getContentFolderPath`
    getContentPath: getContentFolderPath
    
    // or write your own logic for getting path
    getContentPath: async (data) => {
      // `data` - is Eleventy data
      // function can be async
    }
  });
}

By default, library uses are async functions from modules node:fs and node:child_process. You can use sync version of this functions;

const { eleventyPluginContentDates, MODE } = require('@web-alchemy/eleventy-plugin-content-dates');

module.exports = function(eleventyConfig) {
  eleventyConfig.addPlugin(eleventyPluginContentDates, {
    mode: MODE.SYNC
  });
}

Usage

The plugin uses specials values for date fields:

• Date. FS. Created - the date of creation file received from the file system
• Date. FS. Last Modified - the date of modification file received from the file system
• Date. Git. Created - the date of creation file received from the git
• Date. Git. Last Modified - the date of modification file received from the git

Using in frontmatter:

---
createdAt: 'Date. Git. Created'
updatedAt: 'Date. Git. Last Modified'
---

<time datetime="{{ createdAt.toISOString()}}">
  {{ createdAt.toLocaleDateString() }}
</time>

<time datetime="{{ updatedAt.toISOString()}}">
  {{ updatedAt.toLocaleDateString() }}
</time>

Using in 11tydata-files:

const { TIMESTAMPS } = require('@web-alchemy/eleventy-plugin-content-dates');

module.exports = {
  createdAtWithFS: TIMESTAMPS.FS_CREATED,
  updatedAtWithFS: TIMESTAMPS.FS_LAST_MODIFIED,
  createdAtWithGit: TIMESTAMPS.GIT_CREATED,
  updatedAtWithGit: TIMESTAMPS.GIT_LAST_MODIFIED,
}

Low level usage example

You can use @web-alchemy/eleventy-plugin-content-dates as a library without registering the plugin:

// index.11tydata.js
const path = require('node:path');
const { TIMESTAMPS, MODE, computeDate } = require('@web-alchemy/eleventy-plugin-content-dates');

module.exports = {
  eleventyComputed: {
    yourCustomDateField: async function(data) {
      return await computeDate({
        strategy: TIMESTAMPS.GIT_LAST_MODIFIED,
        mode: MODE.ASYNC,
        contentPath: path.dirname(data.page.inputPath),
      })
    },
    
    yourAnotherCustomDateField: function(data) {      
      return computeDate({
        strategy: TIMESTAMPS.FS_CREATED,
        mode: MODE.SYNC,
        contentPath: data.page.inputPath,
      })
    },
  }
}

Caveats of use on CI/CD

Many CI/CD tools, such as Github Actions Checkout, by default does a shallow clone and dates may be incorrect.

Solutions:

• Make deep clone with fetch-depth: '0':

    - name: Checkout
      uses: actions/checkout@v4
      with:
        fetch-depth: '0'

  This is also helpful, if you use git creation dates. But with this method, all branches and tags are pulled out, not just the history of one branch.
• Write your own git commands. Just example:

  - name: Checkout
    run: |
      git clone --depth 1 <REPO> .
      git fetch --unshallow