[wp-trac] [WordPress Trac] #27322: Allow modifying the theme directory stack

[WordPress Trac]

#27322: Allow modifying the theme directory stack
-------------------------+-----------------------------
 Reporter:  rmccue       |      Owner:
     Type:  enhancement  |     Status:  new
 Priority:  normal       |  Milestone:  Awaiting Review
Component:  Themes       |    Version:
 Severity:  normal       |   Keywords:  has-patch
  Focuses:               |
-------------------------+-----------------------------
 Currently, all internal functions first search the current theme's
 directory for a file, then the current parent's directory. This step is
 done manually in things like `locate_template`, `comments_template` and
 others.

 I'd like to propose adding the ability to override this stack. For plugins
 that want to add default templates, they can add this to the bottom of the
 stack and ensure that it works perfectly across the template loader and
 other functions (such as `get_template_part`). It also allows writing
 plugins to handle more complicated theme hierarchies.

 WordPress itself can take advantage of this by adding the `theme-compat`
 directory to the bottom of the stack, allowing fallbacks for things like
 the comment template/etc without needing the custom code that currently
 exists.

 Note that unlike #13239, this does '''not''' allow overriding the template
 hierarchy, only the theme hierarchy.

 Along with this, it makes sense to introduce a `theme_url` function along
 the lines of #18302. I have included that here, since it makes more sense
 to bundle these changes together, IMO.

 Patch attached. No unit tests currently.

--
Ticket URL: <https://core.trac.wordpress.org/ticket/27322>
WordPress Trac <https://core.trac.wordpress.org/>
WordPress publishing platform