.eleventy.js

const fs = require("fs");

const { DateTime } = require("luxon");
const markdownIt = require("markdown-it");
const markdownItAnchor = require("markdown-it-anchor");

const pluginRss = require("@11ty/eleventy-plugin-rss");
const pluginSyntaxHighlight = require("@11ty/eleventy-plugin-syntaxhighlight");
const pluginNavigation = require("@11ty/eleventy-navigation");
const eleventySass = require("eleventy-sass");
const Image = require("@11ty/eleventy-img");

module.exports = function (eleventyConfig) {
  // Copy the `img`, `js`, and `css` folders to the output
  eleventyConfig.addPassthroughCopy("img");
  // eleventyConfig.addPassthroughCopy("css");
  eleventyConfig.addPassthroughCopy("js");

  // Add plugins
  eleventyConfig.addPlugin(pluginRss);
  eleventyConfig.addPlugin(pluginSyntaxHighlight);
  eleventyConfig.addPlugin(pluginNavigation);
  eleventyConfig.addPlugin(eleventySass, {
    sass: {
      style: "compressed",
      sourceMap: false,
    },
  });

  // Add Shortcodes
  eleventyConfig.addShortcode("excerpt", (article) => extractExcerpt(article));
  eleventyConfig.addNunjucksAsyncShortcode("gallery", (galleryname) =>
    imageGallery(galleryname)
  );
  eleventyConfig.addLiquidShortcode("gallery", (galleryname) =>
    imageGallery(galleryname)
  );
  eleventyConfig.addJavaScriptFunction("gallery", (galleryname) =>
    imageGallery(galleryname)
  );
  eleventyConfig.addNunjucksAsyncShortcode("image", imageShortcode);
  eleventyConfig.addLiquidShortcode("image", imageShortcode);
  eleventyConfig.addJavaScriptFunction("image", imageShortcode);

  eleventyConfig.addFilter("readableDate", (dateObj) => {
    return DateTime.fromJSDate(dateObj, { zone: "utc" }).toFormat(
      "dd LLL yyyy"
    );
  });

  // https://html.spec.whatwg.org/multipage/common-microsyntaxes.html#valid-date-string
  eleventyConfig.addFilter("htmlDateString", (dateObj) => {
    return DateTime.fromJSDate(dateObj, { zone: "utc" }).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);
  });

  // Return the smallest number argument
  eleventyConfig.addFilter("min", (...numbers) => {
    return Math.min.apply(null, numbers);
  });

  function filterTagList(tags) {
    return (tags || []).filter(
      (tag) => ["all", "nav", "post", "posts"].indexOf(tag) === -1
    );
  }

  eleventyConfig.addFilter("filterTagList", filterTagList);

  // Create an array of all tags
  eleventyConfig.addCollection("tagList", function (collection) {
    let tagSet = new Set();
    collection.getAll().forEach((item) => {
      (item.data.tags || []).forEach((tag) => tagSet.add(tag));
    });

    return filterTagList([...tagSet]);
  });

  // Customize Markdown library and settings:
  let markdownLibrary = markdownIt({
    html: true,
    linkify: true,
  }).use(markdownItAnchor, {
    permalink: markdownItAnchor.permalink.ariaHidden({
      placement: "after",
      class: "direct-link",
      symbol: "#",
    }),
    level: [1, 2, 3, 4],
    slugify: eleventyConfig.getFilter("slugify"),
  });
  eleventyConfig.setLibrary("md", markdownLibrary);

  // Override Browsersync defaults (used only with --serve)
  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.writeHead(404, { "Content-Type": "text/html; charset=UTF-8" });
          res.write(content_404);
          res.end();
        });
      },
    },
    ui: false,
    ghostMode: false,
  });

  return {
    // Control which files Eleventy will process
    // e.g.: *.md, *.njk, *.html, *.liquid
    templateFormats: ["md", "njk", "html", "liquid"],

    // Pre-process *.md files with: (default: `liquid`)
    markdownTemplateEngine: "njk",

    // Pre-process *.html files with: (default: `liquid`)
    htmlTemplateEngine: "njk",

    // -----------------------------------------------------------------
    // If your site deploys to a subdirectory, change `pathPrefix`.
    // Don’t worry about leading and trailing slashes, we normalize these.

    // 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`

    // Optional (default is shown)
    pathPrefix: "/",
    // -----------------------------------------------------------------

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

function extractExcerpt(article) {
  if (!article.hasOwnProperty("templateContent")) {
    console.warn(
      'Failed to extract excerpt: Document has no property "templateContent".'
    );
    return null;
  }

  if (article.data.excerpt) {
    return article.data.excerpt;
  }

  let excerpt = "";
  const content = article.templateContent;

  // The start and end separators to try and match to extract the excerpt
  const separatorsList = [
    { start: "<!-- Excerpt Start -->", end: "<!-- Excerpt End -->" },
    { start: "<p>", end: "</p>" },
    { start: "<h2>", end: "</h2>" },
  ];

  separatorsList.some((separators) => {
    const startPosition = content.indexOf(separators.start);
    const endPosition = content.indexOf(separators.end);

    if (startPosition !== -1 && endPosition !== -1) {
      excerpt = content
        .substring(startPosition + separators.start.length, endPosition)
        .trim()
        .substring(0, 200)
        .concat("...");
      return true; // Exit out of array loop on first match
    }
  });

  return excerpt;
}

async function imageGallery(galleryname) {
  const theFolder = "./images/" + galleryname;
  const fs = require("fs");
  let gallery = "<div class='photo-gallery'>";
  let files = fs.readdirSync(theFolder);

  for (const file of files) {
    const metadata = await Image(`${theFolder}/${file}`, {
      widths: [300, 960, 1920],
      formats: ["jpeg"],
    });

    const imageAttributes = {
      alt: "",
      sizes: "300w",
      loading: "lazy",
      decoding: "async",
    };

    // You bet we throw an error on missing alt in `imageAttributes` (alt="" works okay)
    const img = Image.generateHTML(metadata, imageAttributes, {
      whitespaceMode: "inline",
    });
    gallery =
      gallery +
      `<a href='/${
        metadata.jpeg[2]?.outputPath ||
        metadata.jpeg[1]?.outputPath ||
        metadata.jpeg[0].outputPath
      }' data-lightbox="${galleryname}">${img}</a>`;
  }

  gallery = gallery + "</div>";
  return `${gallery}`;
}

async function imageShortcode(
  src,
  alt,
  sizes = "(max-width: 400px) 400w, 800w",
  cls = "",
  formats = "jpeg"
) {
  let metadata = await Image(src, {
    widths: [400, 800, 1920],
    formats: [`${formats}`],
  });

  let imageAttributes = {
    class: cls,
    alt,
    sizes,
    loading: "lazy",
    decoding: "async",
  };

  // You bet we throw an error on missing alt in `imageAttributes` (alt="" works okay)
  return Image.generateHTML(metadata, imageAttributes, {
    whitespaceMode: "inline",
  });
}