.mdx proposal
February 9, 2018 at 5:43pm.mdx proposal
February 9, 2018 at 5:43pmFor a while now at ZEIT we've been using
markdown-in-js as a pre-processor with Babel, so that we can write static documents more practically.In practice, our pages end up looking something like this:
import * as components from './components/text'import Video from ./components/video'export markdown(components)`# hello there\`\`\`My code snippet ${<Image />}\`\`\``
In addition to letting us quickly write markdown, it has some really powerful benefits:
- It's still JS, which means we can do imports, define helpers, assert that it's valid via a linter, etc.
- We can embed JSX components inside Markdown. This is a must for us, because we like writing blog posts (https://zeit.co/blog) that have diverse content inside.
However, in my opinion, a lot of the benefits of "writing markdown" are lost. For example, as you see above, escaping code blocks becomes cumbersome.
As a result, I've been playing with an idea in my mind for a potential custom webpack loader and a new format called
mdx, which brings the "best of both worlds" of JSX and Markdown.Imagine
my-blog-post.mdx:import Video from '../components/video'# My blog post```my code!```And here's a video:<Video width={300} src="video.mp4" />
This looks great IMO, however, some important problems remain:
- How do we lint? It should be impossible to include
<Vid>because it's not imported, but<Video>should work. Can we extendeslintto understand.mdx? - How do we defined the default set of components? One option would be to pass them to the webpack loader configuration
- How do we override one component? Let's say we want to use a custom paragraph renderer. An idea here would be to standarize on a series of names, so that you can just do
import P from '../components/paragraph' - How do we prettify it? Another issue we have with our markdown pages is that the markdown inside ends up looking really ugly, unless you painstakingly format it by hand. Can we extend prettier to understand
.mdx?
If someone in the community wants to start playing around with a prototype, please share!
February 9, 2018 at 5:51pm
I've wanted this kind of thing a million times!
This lines up really nicely with recent work on Gatsby: https://github.com/gatsbyjs/gatsby/issues/312
I've gone ahead and open sourced our current experiment with a markdown implementation along the same lines of this proposal: https://github.com/c8r/markdown It's a bit different because we've been experimenting more with `.jsx` code blocks and front matter to handle the JSX/React specific functionality. Though it allows for passing in components that are rendered in place of html elements during the transpilation process. Using mdast/remark and based of remark-react.
What's nice about targeting `.jsx` code blocks is that editors/GitHub will syntax highlight, and a linter could quickly discern what is markdown and what is JSX. Though it's also not quite as expressive as inlined JSX in the document.
I think the proper extension of markdown to allow custom React components to be embedded warrants the special syntax. Reasons for this are:
* We need both *block* level and *inline* level markup constructs for custom components. This is mainly due to how markdown markup is structured — I think you'd need this distinction to allow markdown and React components to be interleaved (e.g. pass some markdown to a React component as `children`).
* JSX (XML-like syntax) is too heavyweight to be embedded into markdown. I figured out you'd want to use such custom components often (there are a lot of use cases for them and not just for some ad-hoc uses).
I'v created a PoC quiet a while ago — https://andreypopp.github.io/reactdown (**warning:** it's not maintained) which exercises the points above by introducing a special syntax for block level and inline level constructs.
Block level constructs called **directives** look like this — https://raw.githubusercontent.com/andreypopp/reactdown/master/src/parse/__tests__/directive-fixture/with-data-children.md
Inline level constructs called **roles** — https://raw.githubusercontent.com/andreypopp/reactdown/master/src/parse/__tests__/role-fixture/multi.md
Reactdown isn't ready and is super alpha and outdated software, be warned. But I believe the idea is sound. :-)