layout: allow arbitrary CSS attributes

[gmarull]

Allow arbitrary CSS attributes when using app.add_css_file() on Sphinx.
It can be useful e.g. to insert media or any other attribute. Note
that rel and type are set by default.

Fixes #1100

[Blendify]

Does feature for other sphinx themes? This is what the basic theme does, does this syntax work?

    {%- for css in css_files %}
      {%- if css|attr("filename") %}
    {{ css_tag(css) }}
      {%- else %}
    <link rel="stylesheet" href="{{ pathto(css, 1)|e }}" type="text/css" />
      {%- endif %}
    {%- endfor %}

[gmarull]

@Blendify thanks for pointing that out! I was not aware of css_tag.

[Blendify]

The change is good, however it requires sphinx 1.8 but currently we support versions down to 1.6 so this will need to be an if else block see https://github.com/readthedocs/sphinx_rtd_theme/blob/master/sphinx_rtd_theme/layout.html#L59 or wait until #1075.

If you use the if else block I will add this to the upcoming 1.0 release.

[Blendify]

Meant to request changes

[Blendify]

The logic here is a bit messed up I'm starting to realize it is a bit more complicated than I originally thought.

 <link rel="stylesheet" href="{{ pathto('_static/' + style, 1) }}" type="text/css" />
  <link rel="stylesheet" href="{{ pathto('_static/pygments.css', 1) }}" type="text/css" />
  {%- for css in css_files %}
    {%- if sphinx_version >= "1.8.0" %}
      {%- if css|attr("filename") %}
        {{ css_tag(css) }}
      {%- else %}
         <link rel="stylesheet" href="{{ pathto(css, 1) }}" type="text/css" />
      {%- endif %}
    {%- else %}
      {%- if css|attr("rel") %}
        <link rel="{{ css.rel }}" href="{{ pathto(css.filename, 1) }}" type="text/css"{% if css.title is not none %} title="{{ css.title }}"{% endif %} />
      {%- else %}
        <link rel="stylesheet" href="{{ pathto(css, 1) }}" type="text/css" />
      {%- endif %}
    {%- endif %}
  {%- endfor %}

[gmarull]

I see filename attribute already present on 1.8.0, so why is the additional check needed?

[Blendify]

Not sure but this is what sphinx does: https://github.com/sphinx-doc/sphinx/blob/3.x/sphinx/themes/basic/layout.html#L97

The case for before 1.8 is to match the template before this commit: sphinx-doc/sphinx@c5d6942

[gmarull]

ok, should be ready now

[gmarull]

@Blendify ping

[Blendify]

Looks good but we are going to hold off until 1.1 release.

[Blendify]

It seems to merge is blocked however, maybe because you force pushed a commit

[benjaoming]

We still support Sphinx 1.6 in 1.1... but will be dropped in 2.0. See: https://sphinx-rtd-theme.readthedocs.io/en/stable/development.html#release-2-0-0

[gmarull]

any chance this can be merged? @Blendify

[agjohnson]

Note, this was merged in #1519