Add filter hook to get_post_format_meta()

[stuntbox]

As per ​a previous request from Alex King, it would be useful if a filter hook could be added to get_post_format_meta(), particularly for plugin and theme builders looking to reformat the output of post formats for uses like HiDPI image plugins, lazy loading techniques, picture element polyfills, etc.

[alexkingorg]

The patch is here: ​http://core.trac.wordpress.org/attachment/ticket/19570/post-format-meta-filter.diff

[markjaquith]

In 24080:

Add a post_format_meta filter.

props alexkingorg. fixes #24162.

[alexkingorg]

Whoops, I think my patch was incomplete - we should also pass the $post_id to the filter so there is context to work with.

Additionally, the $post_id param to the function is listed as optional, but there is nothing to have it fall back on the global $post, I added this as well. The $post_id is passed to get_post_format() which requires the post id (doesn't fall back on global $post).

Sorry for not catching this sooner. Updated patch attached.

[SergeyBiryukov]

Replying to alexkingorg:

Additionally, the $post_id param to the function is listed as optional, but there is nothing to have it fall back on the global $post, I added this as well.

We've replaced global $post references with get_post() in [21735]. 24162.2.diff​ uses get_post() here for consistency.

The $post_id is passed to get_post_format() which requires the post id (doesn't fall back on global $post).

It does fall back to the global, via get_post(). [24057] made that clear in the description. get_post_meta(), however, does not.

[alexkingorg]

Hmm, interesting. I hadn't realized about the standardization on get_post() vs global $post, thanks for the explanation.

This does introduce an additional set of SQL calls for loading up the post if it's not already in object cache. Doesn't seem necessary if the $post_id isn't 0.

Is it the job of this function to check that the post ID is valid? Seems like a lot of responsibility to put on this guy. :)

[alexkingorg]

Here's a slight mod so that the filter always gets called.

[alexkingorg]

always call filters

[DrewAPicture]

24162.3.diff​ works as expected for me.

[ocean90]

[24399] / #24452

[alexkingorg]

We're just throwing away code and ideas relating to post formats now?

[SergeyBiryukov]

All the patches and ideas are still available for future reference.