Check for specific post formats with `current_theme_supports()`

[ericmann]

A question in IRC reminded me that there's no efficient way to check if a specific post format exists. At the moment, current_theme_supports() is an all-or-nothing Boolean value ... either the theme supports post formats or it doesn't. There's no way to check for specific support for a particular format, say, "aside."

This could be added to current_theme_supports() pretty easily and is done so in the attached patch.

• current_theme_supports( 'post-formats' ) will return true if any post format is supported
• current_theme_supports( 'post-formats', 'aside' ) will return true if the "aside" post format is supported

Allow selection of specific post type in current_theme_supports()

This is exactly what i was looking for. Will test and get back.

Change variable name to match what we're doing. Use a cleaner return.

I think this patch can be simplified further. The logic is the same as that for post thumbnails, so it can use the same case statement.

case 'post-thumbnails':
case 'post-formats':
// bla

Haven't tested it though.

Replying to johnbillion:

I think this patch can be simplified further. The logic is the same as that for post thumbnails, so it can use the same case statement.

It's not entirely the same though due to:

if ( true === $_wp_theme_features[$feature] )  // Registered for all types
    return true;

for post-thumbnails.

Replying to johnbillion:

I think this patch can be simplified further. The logic is the same as that for post thumbnails, so it can use the same case statement.

I'm tempted to agree, but I'm concerned that a fall-through case statement might not be very clear for others looking at the code later. Considering ​this coding standard:

In general, readability is more important than cleverness or brevity.

Fall-though case statements usually aren't very self-explanatory ... particularly if we ever add new cases to the statement. I'd rather leave in the full code now than need to re-add it if/when we add new cases down the road.

In [18720]:

Allow current_theme_supports() to be used to check for specific post formats. Props ericmann. Fixes #18691.

In [18721]:

Make use of specific post format support in current_theme_supports(). See #18691.

Related: #11611