I Think I Fixed the RSS Markup?

Looking back at when I just started writing, I'm happy with where it ended up. Tinkering with it is a good adventure, but some things are way more painful than they have to be.

One of them is figuring out how to render the formatted posts body in the RSS feed. The problem is that the post body is in MDX, and Contentlayer has opinions on how it can be rendered:

// You grab the component based on a posts. body.
const MDXContent = getMDXComponent(post.body.code);
return (
    <MDXContent components={mdxComponents} />
)

// You grab the component based on a posts. body.
const MDXContent = getMDXComponent(post.body.code);
return (
    <MDXContent components={mdxComponents} />
)

That's great for pages composed of React components. But there's a problem. In a "static" Next.js site you can either pre-generate RSS feeds in a build-time script, or render the feed in a Next.js page, or an API route.

Neither of those approaches give you a page that you can compose with React code. Usually, you'd use rss or feed library and shove the result in a file, or an HTTP response.

To render that outside of a React context, you can hypothetically to ReactDOMServer.renderToString, but Vercel does not like that.

Workaround for MDX in RSS is to, well, not use MDX in RSS

Instead, I ended up extracting up the remark and rehype plugins I'm using into a reusable block, and making a separate method that renders post markup with regular remark → rehype pipeline, without MDX.

Sprinkled with some //@ts-ignore, this works, except for custom MDX components, which, if we're honest, probably won't be a good fit for an RSS reader anyway. If you go that path, just make sure to have alternative Rehyp plugins that would clean out the custom component markup.

Inlining Images in RSS

The other tricky problem in Obsidian + Next.js combo are paths to posts and assets. Because the site repository has posts in ./content/{type}/{slug}.md, the relative path from the root is going to be different, so I had to preprocess them:

• remark-wiki-links has hrefTemplate that works great to preface the post paths.
• You can treat <img> as a custom MDX component and override image path in src (or use any rehype plugin to do a similar flow).

But, for the RSS feed and for a newsletter, you'd have to either set absolute asset URLs, or inline them. So I've set up rehype-embed-images replace image sources with base64 encoded images. That way, RSS readers should be able to pick them up.

Just use Jekyll

Seriously, there are a number of ways to build a blog the easy way. Author in Obsidian, iA Writer, Ulysses, whatever you want — just publish with something battle-tested and simple, like Jekyll. Or Obsidian Publish. Or maybe Astro? I haven't tried that one yet. But Next.js for a blog is a bit of an overkill.

Maybe edge opengraph images were worth it? Not quite sure.