Building a blog with Svelte, Sapper, and Markdown

3 min readMar 7, 2020

In this post, we will build a website with a blog using svelte, and sapper.

What is Svelte?

Svelte is a new javascript framework come on the table, Svelte has a philosophy that helps you manipulate the DOM without using any additional techniques like virtual DOM, Svelte compile your code on the build time, and you can update your app easily using reactivity.

What is Sapper?

Sapper is a Server Side framework on top of Svelte helps you create PWA apps with a good SEO and file system based routing.

How to init the project?

We are going to use the starter template provided by the Sapper team, open your favorite terminal and write the following command:

npx degit "sveltejs/sapper-template#rollup" cool-blog cd /cool-blog npm install

After installing the dependencies, you should be good to go and start your server.

Voila, 🎉 the application now up and running.

Let’s open the project in your favorite editor. and go to the blog folder inside the src/routes.

We have several files there:

| src | routes | blog - index.svelte, - index.json.js - [slug].svelte - [slug].json.js - _posts.js

How does routing work in sapper?

we have two types the pages, and server routes.

Pages

The filename determines the route. For example: src/routes/blog/index.svelte refer to the route /blog.

For Dynamin routing. we going to use [slug]. For example, ser/routes/blog/[slug].svelte refer to the route /blog/the-whatever-blog-name

Server

Server routes are modules written in .js files that export HTTP functions. For example, get endpoint to retrieve the blog details:

import posts from './_posts.js'; const lookup = new Map(); posts.forEach( { lookup.set(post.slug, JSON.stringify(post)); }); export { const { slug } = req.params; if (lookup.has(slug)) { res.writeHead(200, { 'Content-Type': 'application/json', }); res.end(lookup.get(slug)); } else { res.writeHead(404, { 'Content-Type': 'application/json', }); res.end( JSON.stringify({ message: `Not found`, }) ); } }

Create a content directory on the root of your project. inside this directory, we going to create a file called sample-post.md file.

// sample-post.md --- slug: 'sample-blog' title: 'Sample blog.' --- # Sample title this is a sample blog post. ``javascript console.log("test code highlight") ``

slug has to be the same as the file name, So we can easily read the file with the slug. You can add more than title, and slug, For Example, Date, keywords or whatever you need to add.

To list all blogs on /blog route open src/routes/blog/index.json.js

You need to install an extra package called gray-matter that helps you parse the front matter data title, and slug from the markdown.

npm install gray-matter

If you navigate to /blog route you should have a page similar to this:

Now we need to handle the post route. open src/routes/blog/[slug].json.js

import path from "path"; import fs from "fs"; import grayMatter from "gray-matter"; import marked from "marked"; import hljs from "highlight.js"; const getPost = fs.readFileSync(path.resolve("content", `${fileName}.md`), "utf-8"); export { const { slug } = req.params; const post = getPost(slug); const renderer = new marked.Renderer(); renderer.code = (source, lang) => { const { value: highlighted } = hljs.highlight(lang, source); return `<pre class='language-javascriptreact'><code>${highlighted}</code></pre>`; }; const { data, content } = grayMatter(post); const html = marked(content, { renderer }); if (html) { res.writeHead(200, { "Content-Type": "application/json" }); res.end(JSON.stringify({ html, ...data })); } else { res.writeHead(404, { "Content-Type": "application/json" }); res.end( JSON.stringify({ message: `Not found` }) ); } }

Two new packages we need to install

marked: help us to convert the markdown file into HTML.
highlight.js: add highlights to the code blocks.

npm install highlight.js marked

In src/client.js we import Github styles for highlight.js.

import "highlight.js/styles/github.css";

conclusion

You now ready to go and add more styles for your website and customize the blog elements styles. to go live using Netlify, Github Page or any service.

Originally published at https://www.mahmoudashraf.dev.