[PATCH v4 00/16] Render READMEs inline in tree view

[Jason A. Donenfeld]

Hey John,

On Thu, Jun 28, 2018 at 10:29 AM John Keeping <john at keeping.me.uk> wrote:
> Yeah, I don't think there's any way to avoid exec'ing twice in source
> view - we need to run the source filter for output and we need the
> render filter to tell us whether we should output a link to the rendered
> content.

Let's do it this way then. Since rendering anyway usually amounts to:

case "$(printf '%s' "$1" | tr '[:upper:]' '[:lower:]')" in
        *.markdown|*.mdown|*.md|*.mkd) exec ./md2html; ;;
        *.rst) exec ./rst2html; ;;
        *.[1-9]) exec ./man2html; ;;
        *.htm|*.html) exec cat; ;;
        *.txt|*) exec ./txt2html; ;;
esac

Then we can just reimplement the dispatcher in Lua, and this whole
issue goes away.

> That's what the asset-path feature elsewhere in this series does,
> especially if we take your idea of passing the URL path to the file
> being rendered.  So we should make that change and pass the path to the
> file instead of just a directory.

Right.

> It's /source/ instead of /tree/ in the current series and I think that's
> better than a query parameter since this is a somewhat different view.

I saw that. And indeed that seems like a good way of doing it.

>
> > - When source-filter is used, cgit prints its usual line numbers.
> > - If source-filter fails, we print our nice hexdump or plaintext printer.
>
> These two are "source-filter usage is unchange", right?

Yes.

> Yes, that looks good to me, modulo figuring out exactly how
> render-filter operates.

render-filter will operate the same way as the current about-filter,
with two exceptions:

- If it returns error 127, then it means rendering wasn't supported
and we should fall back to source view (in the case of it being loaded
from /tree).
- It is passed a full path to the raw files, so that it can generate
correct relative includes.

I think with that settled (if you agree), the previous series can be
reworked to function in this manner? The full plan is looking like:

- We retain commit-filter, source-filter, and owner-filter as we have them now.
- We rename about-filter to render-filter.
- render-filter gets passed a fuller filename with useful path
information for printing out iframes, img tags, and so forth.
- render-filter returns 127 if it does not have a renderer for that file.
- Viewing files in /tree defaults to render-filter. If that returns
127, it falls back to source-filter.
- Viewing files in /source goes straight to source-filter and skips
render-filter.
- When render-filter is used in /tree, cgit shows in the top bar a
helpful link to go to /source.
- We remove readme and instead introduce readme-filename instead.
- We introduce a global and a .repo level about-readme that takes the
above syntax.
- We introduce tree-readme=1/0.