INDEX

Scully Plugins for Algolia Search and HTML Header Tag Links and More!

#Scully#Algoila#Firebase#Plugins#Blog

By Caleb Ukle at

Disclaimer: At the time of writing this scully is in a Alpha period. So things are likely to change. I will provide any updates once a beta/v1 release is made if needed.

If you want to learn more about the move from Gatsby to Scully or want to know what scully even is check out my post here.

I just added a new plugin. Blur Up Images! You can learn more here

First thing to note before getting into the plugins, each plugin has to be registered with a validator function. For all these plugins the validator wasn't needed so an empty array in return. I show all the registration and usage for each plugin. That is what the last couple lines per plugin is about.

Plugin Overview

Jump to each plugins location for what you need

This plugin requires jsdom, npm i -D jsdom

I like the ability to directly link to a section of an article , and I wanted to keep that functionality for my site. With scully being so new I couldn't find a plugin that already did this work for me. So below you'll find the code that adds the hash/pound/number/octothorpe or whatever your preferred name the icon/symbol you see next to all the headers on this site.

/* addLinksToHeader.plugin.ts */

const { registerPlugin } = require("@scullyio/scully");
const { log, yellow, green, red, logError } = require(
  "@scullyio/scully/utils/log",
);
const jsdom = require("jsdom");
const { JSDOM } = jsdom;

/**
 * @param html {string}
 * @param route { {route: string}}
 * @returns {Promise<string>}
 */
const addLinksToHeader = async (html, route) => {
  try {
    // Create dom from the HTML string so we can query it for all headers
    const dom = new JSDOM(html);
    const { window } = dom;

    const headers = window.document.querySelectorAll(`h1, h2, h3, h4, h5`);

    // Loop over all headers and add the link
    headers.forEach((h) => {
      if (!!h.id) {
        const link = window.document.createElement(`a`);

        // add whatever svg icon you want here
        link.innerHTML =
          `<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 448 512"><path d="M440.667 182.109l7.143-40c1.313-7.355-4.342-14.109-11.813-14.109h-74.81l14.623-81.891C377.123 38.754 371.468 32 363.997 32h-40.632a12 12 0 0 0-11.813 9.891L296.175 128H197.54l14.623-81.891C213.477 38.754 207.822 32 200.35 32h-40.632a12 12 0 0 0-11.813 9.891L132.528 128H53.432a12 12 0 0 0-11.813 9.891l-7.143 40C33.163 185.246 38.818 192 46.289 192h74.81L98.242 320H19.146a12 12 0 0 0-11.813 9.891l-7.143 40C-1.123 377.246 4.532 384 12.003 384h74.81L72.19 465.891C70.877 473.246 76.532 480 84.003 480h40.632a12 12 0 0 0 11.813-9.891L151.826 384h98.634l-14.623 81.891C234.523 473.246 240.178 480 247.65 480h40.632a12 12 0 0 0 11.813-9.891L315.472 384h79.096a12 12 0 0 0 11.813-9.891l7.143-40c1.313-7.355-4.342-14.109-11.813-14.109h-74.81l22.857-128h79.096a12 12 0 0 0 11.813-9.891zM261.889 320h-98.634l22.857-128h98.634l-22.857 128z"/></svg>`;
        link.href = `${route.route}#${h.id}`;
        link.title = `Link to this point`;

        // custom class for styling
        link.classList.add(`header-link`);
        h.appendChild(link);
      }
    });

    log(green(`Added heading links for ${route.route}`));
    return dom.serialize();
  } catch (e) {
    logError(
      `${red("Issue creating header links for")} ${yellow(route.route)}`,
    );
  }
  return html;
};

const validator = async (conf) => [];
registerPlugin("render", "addLinksToHeader", addLinksToHeader, validator);

module.exports.addLinkToHeader = addLinksToHeader;

This plugin requires algolia search, npm i algoliasearch

Another feature I needed is the ability to update the sites search index when a new post is created. I use Algolia to power my searching needs. I highly recommend the service and they have a generous free tier.

This plugin is about updating your algolia post index, if you want to see the how I implemented search you can check out the source code here

A lot of the code for this was ripped straight from the algolia gatsby plugin source code, found here

/* updateAlgoliaIndex.plugin.js */

const { registerPlugin } = require("@scullyio/scully");
const { log, yellow, green, red, logError } = require(
  "@scullyio/scully/utils/log",
);
const algoliasearch = require("algoliasearch");

const SETTINGS = { attributesToSnippet: [`excerpt: 20`] };

const INDEX_NAME = `Blog_Posts`; // set your index name here

/**
 * @param html
 * @param options {
 * route: string;
 * data: {}
 * @returns {Promise<string>}
 */
const updateAlgoliaIndex = async (html, options) => {
  try {
    const client = initAlgoliaClient();
    const payload = buildPayload(options);

    const index = client.initIndex(INDEX_NAME);
    const mainIndexExists = await indexExists(index);
    // you can use a temp index and then copy that into your main index. I don't do this
    // check the gatsby plugin to see how it's used https://github.com/algolia/gatsby-plugin-algolia/
    const tmpIndex = client.initIndex(`${INDEX_NAME}_tmp`);
    const indexToUse = index; // mainIndexExits ? index : tmpIndex

    log(`Using [${indexToUse.indexName}]`);

    // if (mainIndexExists) {
    //   log(`copying existing index`)
    //   await scopedCopyIndex(client, index, tmpIndex)
    // }

    // Save Items in your index
    const { taskID } = await indexToUse.saveObject(payload);
    await indexToUse.waitTask(taskID);

    if (SETTINGS) {
      const { taskID } = await indexToUse.setSettings(SETTINGS);
      await indexToUse.waitTask(taskID);
    }
    //
    // if (mainIndexExists) {
    //   log(`moving copied index to main index`)
    //   await moveIndex(client, tmpIndex, index)
    // }

    log(green(`Updated index for [${payload.title}]`));
  } catch (e) {
    logError(red(JSON.stringify(e, null, 2)));
  }

  return html;
};

function initAlgoliaClient() {
  let isError = false;
  // Make sure you have these in your env variables
  // I use dotenv
  const appId = process.env.ALGOLIA_APP_ID;
  const apiKey = process.env.ALGOLIA_ADMIN_KEY;
  if (!appId) {
    logError(red(`ALGOLIA_APP_ID not found in environment variables!`));
    isError = true;
  }
  if (!apiKey) {
    logError(red(`ALGOLIA_ADMIN_KEY not found in environment variables!`));
    isError = true;
  }
  if (isError) {
    throw "Make sure environment variables are set";
  }

  return algoliasearch(appId, apiKey);
}

/**
 * @param options
 * @returns {{date: *, path: *, description: *, title: *, objectID: number, tags: *[]}}
 */
function buildPayload(options) {
  // prevent leakage into other blog posts index payload
  const crypto = require("crypto");
  const hash = crypto.createHash("sha256");
  const { data, route } = options;
  hash.update(data.title, "utf8");
  return {
    title: data.title,
    description: data.description,
    tags: [...data.tags],
    path: route,
    date: data.date,
    // Build an object Id with a hash from our project title
    objectID: parseInt(hash.digest("hex").slice(0, 15), 16),
    createIfNotExists: true,
  };
}

/**
 * Does an Algolia index exist already
 *
 * @param index
 */
async function indexExists(index) {
  try {
    const { nbHits } = await index.search();
    return nbHits > 0;
  } catch (e) {
    return false;
  }
}

/**
 * Copy the settings, synonyms, and rules of the source index to the target index
 * @param client
 * @param sourceIndex
 * @param targetIndex
 * @return {Promise}
 */
async function scopedCopyIndex(client, sourceIndex, targetIndex) {
  const { taskID } = await client.copyIndex(
    sourceIndex.indexName,
    targetIndex.indexName,
    {
      scope: ["settings", "synonyms", "rules"],
    },
  );
  return targetIndex.waitTask(taskID);
}

/**
 * moves the source index to the target index
 * @param client
 * @param sourceIndex
 * @param targetIndex
 * @return {Promise}
 */
async function moveIndex(client, sourceIndex, targetIndex) {
  const { taskID } = await client.moveIndex(
    sourceIndex.indexName,
    targetIndex.indexName,
  );
  return targetIndex.waitTask(taskID);
}

const validator = async (conf) => [];
registerPlugin("render", "updateAlgoliaIndex", updateAlgoliaIndex, validator);

module.exports.updateAlgoliaIndex = updateAlgoliaIndex;

A specific thing to note about the algolia search plugin, each objectId is a hash of the blog post title. If you change the title of the post, you'll get a new item in your index. You'll need to manually delete the old item from the algolia web console. Otherwise, you'll have multiple items pointing to the same place,

Firebase Firestore

This plugin requires the firebase admin sdk, npm i -D firebase-admin

I also save the posts in Firestore which powers the like/heart/favorite feature you see on these posts.

/* addPostToFirebase.plugin.ts */

const { registerPlugin } = require("@scullyio/scully");
const { log, logError, red, green } = require("@scullyio/scully/utils/log");
const admin = require("firebase-admin");
// service account json you can download from the firebase console.
// Make sure to save it all as one line in your .env file
const serviceAccount = JSON.parse(process.env.FIREBASE_CONFIG);

admin.initializeApp({
  credential: admin.credential.cert(serviceAccount),
  databaseURL: "", // Add you're database url here
});
const db = admin.firestore();

const addPostToFirebase = async (html, route) => {
  try {
    // Add to Firestore based on route of blog
    await db.doc(`${route.route}`).set(route, { merge: true });
    log(green(`Added ${route.route} to Firebase`));
  } catch (e) {
    logError(red(`Issue adding ${route.route} to Firebase`));
    logError(red(JSON.stringify(e, null, 2)));
  }

  return html;
};

const validator = async (conf) => [];

registerPlugin("render", "addPostToFirebase", addPostToFirebase, validator);

module.exports.addPostToFirebase = addPostToFirebase;

Using Plugins

Now that you have these plugins defined. We need to tell scully to use them. All of the plugins shown are render plugins. There are other plugins such as router or fileHandler

/* scully.{your-project}.config.js */
// Set env variables
require("dotenv").config();

// import plugins
require("./plugins/addLinksToHeader.plugin.ts");
require("./plugins/updateAlgoliaIndex.plugin.js");
require("./plugins/addPostToFirebase.plugin.ts");
exports.config = {
  projectRoot: "./src",
  projectName: "calebukle-com",
  outDir: "./dist/static",
  routes: {
    "/blog/:slug": {
      type: "contentFolder",
      // Render plugins go here. Should match the export name
      postRenderers: [
        "addLinksToHeader",
        "updateAlgoliaIndex",
        "addPostToFirebase",
      ],
      slug: {
        folder: "./blog",
      },
    },
  },
};

I hope that helps you with making your own custom Scully plugins. If you want more information about Scully plugins, you can check out the official docs here and you can find some examples of plugins here.

If you want to know more about my thoughts on Scully then check out this post here.

Thanks for reading!