unified VS remark

From TFA:

> My idea was that surely it's possible to write a bunch of markdown, and then have that get wrapped in a bunch of JSX tags that come pre-styled, using the styles of your existing repo? For example, what I expected was to be able to write *test* (Markdown for bold) and then get a component that looked liketest where is a library-defined React component

It surely is possible, so perhaps I can share some links if others are wondering the same thing.

If you like to roll your own solution for that, you can use the unified ecosystem: https://unifiedjs.com/

However, if you want JSX just do what everyone does and reach for MDX:

Styling the blog, figure out the eco-system within UnifiedJs, remark-rehype, oh boy, I could write another blog with that.

To build the Markdown editor (and the preview, mostly), I decided to use unified, an ecosystem of tools allowing the developer to parse a format into an abstract tree and back into another format (for example, markdown to html) and modify said tree (for example, to add specific classes to certain html elements before they are converted to an actual html string. The basics of how to do so can be found in this article, but they mostly consist of:

It’ll take you a few hours to become proficient in the “unified” syntax tree libraries. So worth it. Easy fully customized conversion to/from html, react, plain text, markdown, you name it. https://unifiedjs.com/

Why universal? Because a lot of languages are simillar in a bunch of ways and it might be good to reuse existing parts of the compiler to speed up the process of writing new DSLs for example. Also a pretty big use-case is not for compilers itself but just for transformers like Markdown to HTML, there are already a lot of libraries (like https://github.com/unifiedjs/unified for ASTs and https://tree-sitter.github.io/tree-sitter/ for parsing) that try achieve similar goals but they are not working together.

Unified is a framework to process Markdown. It's a plugin-based tool that allows you to inspect and modify the way Markdown is converted to other formats like HTML.

under the hood, the markdown is parsed by the unified remark and rehype processors, which in turn under the hood manipulate the markdown + HTML as an AST, which gives a lot of flexibility on parsing and rendering markdown. The editor uses them as plugins, which allows me to pick the features and inject them into the editor, one such injectable feature is the custom-made "copy from anywhere & paste as markdown" feature.

Having the flexibility to create custom React Components for markdown is essential and with react-markdown, we can achieve this in just a few lines of code. Boosting performance, increasing link security, and having overall increased capabilities for our markdown data are what we achieve here. Aside from the improvements within our application, this component is super easy to use and taps us into the unifiedjs (giving us superpowers!).

The Markdown processor used unified assets.

I also didn't try this tool but it's called RemarkJS which is named too similar to revealjs.

remark. Primarily, this is a linter for Markdown. Additionally, thanks to its numerous plugins, it allows us to perform additional checks for grammatical mistakes within the content itself. Before using this linter, our content was not scrutinized to this extent.

Rehype and Remark are plugins used to transform and manipulate the HTML and Markdown content of a website, helping to enhance its functionality and appearance.

I usually combine remark-parse, remark-rehype and rehype-react to transform markdown into react components. The configuration of the processor is like:

Astro content collection are as simple as a folder containing a bunch of Markdown (or Markdoc or MDX) files if that's the only thing you need, but they can also do relationship matching between different collections, frontmatter validation using zod and you can also customize how the markdown is parsed and translated to html using rehype and remark and their plugin ecosystem.

On my personal blog I have few external links in my posts. I wanted to keep people on my website by applying target="_blank" on external (those what don't reference to my site) links. This is a common and good practice too. I write my content in Markdown, so I decided to write a remark plugin. It is simple to implement, just few lines of code.

Although we are building a custom table of contents, we won't have to write everything from scratch. To separate the Markdown/MDX content from the front matter, we'll use the Gray-matter package. It is optional in case you don't have front matter in your Markdown files. To process the Markdown itself, we'll use the Remark package. We'll also need the unist-util-visit package for traversing node trees and mdast-util-to-string for getting the text content of a node.

That's all to render the post as HTML, there are lots of things you can do to customize the results, you can check the remark plugins and rehype plugins to pass as props to and you can also take a look at some other bloggers if you're looking for different styles for example Lee Robinson's or if you liked mine.

contentlayer uses remark to parse the markdown in an mdast. We can now use remark plugins to modify the mdast. Then rehype comes into play and converts the mdast into a hast. rehype plugins can now modify the hast. Finally the hast is converted into react components.

Now we have our Cloudinary account set up, we can use it with Docusaurus. To do so, we need to create a remark plugin. This is a plugin for the remark markdown processor. It's a plugin that will transform the markdown image syntax into a Cloudinary URL.