Fancier Source view [Was: Re: [PATCH v4 00/16] Render READMEs inline in tree view]

[John Keeping]

On Wed, Jun 27, 2018 at 07:26:13PM +0200, Jason A. Donenfeld wrote:
> Splitting out this issue into a different thread, because I think it's
> orthogonal to the other topic.
> 
> On Wed, Jun 27, 2018 at 7:18 PM Jason A. Donenfeld <Jason at zx2c4.com> wrote:
> > In adding rendering of arbitrary files in blob view, this is
> > essentially a fancy source view, with the one caveat of our
> > interesting handling of line numbers.
> 
> People click a .c file and they get pygments highlighting. That's
> good. People click a .pdf or a .md and they get either a hexdump or a
> highlighted .md source. Github has made different behavior more
> popular -- namely, rendering the .pdf and the .md. The obvious way to
> handle this is augmenting the source-view to spit something different
> out.
> 
> Alternatively, my previously proposed readme-filter could be renamed
> to render-filter, and we could do everything in one place with one
> filter, and decide exclusively on the basis of filetype.
> 
> Either way, we have this issue of line numbers. We have a few ways of
> handling this:
> 
> a. Not print them ever when a source-filter/render-filter is
> specified, leaving that up to the renderer to do.
> b. If the renderer doesn't want line numbers, it can return a special
> exit code (197, for example) to indicate that to cgit.
> c. If the renderer doesn't want line numbers, it can just omit some
> !important css to remove them at the end.
> d. We introduce a maze of filetype selection rendering logic options.
> e. Something else?
> 
> I'm most inclined to go with a or b, but neither seems entirely
> appealing. Thoughts?

d. is basically what we have with "render.<ext>" in this series, but I
think e. might be better.  Specifically, I think we shouldn't conflate
source and rendered views because syntax highlighted Markdown, or SVG,
or HTML is still potentially useful.

If source and rendered views are distinct, then source view always has
line numbers (or it's a hex dump) and we just need the filter to return
a special exit status to mean "this file is unsupported", and we disable
the rendered view when that happens.

As an extension, we could disable the source view if rendering is
supported and the file looks like binary, so that the hex dump isn't
available when we have a better option.


John