.eleventy.js

const { DateTime } = require("luxon");
const fs = require("fs");
const pluginRss = require("@11ty/eleventy-plugin-rss");
const pluginSyntaxHighlight = require("@11ty/eleventy-plugin-syntaxhighlight");
const pluginNavigation = require("@11ty/eleventy-navigation");
const markdownIt = require("markdown-it");
const markdown = require('markdown-it')({ html: true })

module.exports = function(eleventyConfig) {
  eleventyConfig.addPlugin(pluginRss);
  eleventyConfig.addPlugin(pluginSyntaxHighlight);
  eleventyConfig.addPlugin(pluginNavigation);

  eleventyConfig.setDataDeepMerge(true);

  eleventyConfig.addLayoutAlias("post", "layouts/post.njk");
  
  eleventyConfig.addFilter('markdown', value => {
    return markdown.render(value);
  })

  eleventyConfig.addFilter("readableDate", dateObj => {
    return DateTime.fromJSDate(dateObj, {zone: 'Europe/Paris'}).setLocale("fr").toFormat("dd/LL/yyyy");
  });

  // https://html.spec.whatwg.org/multipage/common-microsyntaxes.html#valid-date-string
  eleventyConfig.addFilter('htmlDateString', (dateObj) => {
    return DateTime.fromJSDate(dateObj, {zone: 'Europe/Paris'}).setLocale("fr").toFormat('yyyy-LL-dd');
  });

  // Get the first `n` elements of a collection.
  eleventyConfig.addFilter("head", (array, n) => {
    if(!Array.isArray(array) || array.length === 0) {
      return [];
    }
    if( n < 0 ) {
      return array.slice(n);
    }

    return array.slice(0, n);
  });

  function findNavigationEntriesExtended(nodes = [], key = '') {
    let pages = [];
    for(let entry of nodes) {
      if(entry.data && entry.data.eleventyNavigation) {
        let nav = entry.data.eleventyNavigation;
        if(!key && !nav.parent || nav.parent === key) {
          pages.push(Object.assign({}, nav, {
            url: nav.url || entry.data.page.url,
            data: entry.data,
            pluginType: 'eleventy-navigation'
          }, key ? { parentKey: key } : {}));
        }
      }
    }
  
    return pages.sort(function(a, b) {
      return (a.order || 0) - (b.order || 0);
    }).map(function(entry) {
      if(!entry.title) {
        entry.title = entry.key;
      }
      if(entry.key) {
        entry.children = findNavigationEntriesExtended(nodes, entry.key);
      }
      return entry;
    });
  }

  eleventyConfig.addNunjucksFilter('eleventyNavigationExtended', findNavigationEntriesExtended);

  function findNavigationEntryByKeys(nodes = [], keys = []) {
    let pages = [];
    
    for (let key of keys) {
      for (let entry of nodes) {
        if (entry.data && entry.data.eleventyNavigation && entry.data.eleventyNavigation.key) {
          let entryKey = entry.data.eleventyNavigation.key;
          
          if (entryKey === key) {
            pages.push({
              title: entry.data.title,
              url: entry.url || entry.data.page.url,
              data: entry.data,
              pluginType: 'eleventy-navigation'
            });

            break;
          }
        }
      }
    }

    return pages;
  }

  eleventyConfig.addNunjucksFilter('eleventyNavigationByKeys', findNavigationEntryByKeys);

  eleventyConfig.addPassthroughCopy({
    'api': 'api',
    'img': 'img',
    'css': 'css',
    'js': 'js',
    'docs': 'docs',
    'fonts': 'fonts',
    'favicons': 'favicons',
    'CNAME': 'CNAME',
    '.well-known/pki-validation/01a55d39-ad7f-4bd3-badc-bbf5f725da7b.txt': '.well-known/pki-validation/01a55d39-ad7f-4bd3-badc-bbf5f725da7b.txt'
  });

  /* Markdown Overrides */
  let markdownLibrary = markdownIt({
    html: true,
    breaks: true,
    linkify: true,
    typographer: true,
    quotes: ['«\xA0', '\xA0»', '‹\xA0', '\xA0›']
  });
  eleventyConfig.setLibrary("md", markdownLibrary);

  // Browsersync Overrides
  eleventyConfig.setBrowserSyncConfig({
    callbacks: {
      ready: function(err, browserSync) {
        const content_404 = fs.readFileSync('_site/404.html');

        browserSync.addMiddleware("*", (req, res) => {
          // Provides the 404 content without redirect.
          res.write(content_404);
          res.end();
        });
      },
    },
    ui: false,
    ghostMode: false
  });

  return {
    templateFormats: [
      "md",
      "njk",
      "html",
      "liquid"
    ],

    // If your site lives in a different subdirectory, change this.
    // Leading or trailing slashes are all normalized away, so don’t worry about those.

    // If you don’t have a subdirectory, use "" or "/" (they do the same thing)
    // This is only used for link URLs (it does not affect your file structure)
    // Best paired with the `url` filter: https://www.11ty.dev/docs/filters/url/

    // You can also pass this in on the command line using `--pathprefix`
    // pathPrefix: "/",

    markdownTemplateEngine: "liquid",
    htmlTemplateEngine: "njk",
    dataTemplateEngine: "njk",

    // These are all optional, defaults are shown:
    dir: {
      input: ".",
      includes: "_includes",
      data: "_data",
      output: "_site"
    }
  };
};