Add a better 404 page to the default theme

[jacobobryant]

Currently you just get the default Netlify not found page, e.g. https://biffweb.com/no-page-here:

[joerter]

Hey Jacob, I'm looking into this one. I found this article from Netlify that says you need to add a 404.html page to your build and it will be picked up automatically.

I tried adding a 404 page to the theme, but it renders as a 404 folder with an index.html file inside. Do you think the best way then is to make some special handling for rendering a 404 page, or do you think there's a different approach?

[jacobobryant]

I just peeked at the code to refresh my memory, and it looks like the render! function currently is hard-coded to always put a index.html on the end: https://github.com/jacobobryant/platypub/blob/master/themes/default/src/com/platypub/themes/common.clj#L158

It'd probably be best to modify that function so e.g. if you put {"/404.html" ...} in your pages var, it'll render to that file instead of to /404.html/index.html (which is what it does currently, right?). Biff does something like that for the :static-pages feature: https://github.com/jacobobryant/biff/blob/master/src/com/biffweb/impl/rum.clj#L92

If we copied Biff's algorithm as-is (i.e. check to see if the path ends in a slash, and if so add a index.html), that might introduce too breaking of a change--in platypub, currently if someone has "/foo" as one of their paths, it gets rendered to "/foo/index.html", so it'd be nice to keep that behavior.*

How about change render! so that it only adds an index.html if the path doesn't already end in .html?

*Realistically I think there's a total of like 3 people using platypub currently, but still nice to avoid breaking changes out of principle/habit...

[joerter]

I like it! So something like this for pages,

(def pages
  {"/" landing-page
   "/archive/" archive-page
   "/subscribe/" subscribe-page
   "/404.html" not-found-page})

Would create index.html, /archive/index.html, /subscribe/index.html, and 404.html

[jacobobryant]

yep!