add_meta_box() should accept array of post types

[coffee2code]

I often find myself defining an identical meta box for different post types. It would be nice if add_meta_box() accepted an array as its $page argument. For backward-compatibility the function will still accept a string. So for all else being equal, the same metabox could be added to multiple post types in a single line of code. Of course, if the meta box needs per-post_type configuration, add_meta_box() could be called separately for each post type.

Example:

add_meta_box( 'my-geo', 'Geolocation Info', array( &$this, 'geo_form' ), 'post', 'side' );
add_meta_box( 'my-geo', 'Geolocation Info', array( &$this, 'geo_form' ), 'page', 'side' );
add_meta_box( 'my-geo', 'Geolocation Info', array( &$this, 'geo_form' ), 'event', 'side' );

would become:

add_meta_box( 'my-geo', 'Geolocation Info', array( &$this, 'geo_form' ), array( 'post', 'page', 'event' ), 'side' );

Of course, the former would continue to work.

One could certainly loop through the post types manually to call add_meta_box(), but I think the proposed patch clarifies coding intention.

Patch is attached. (In the patch, I didn't indent the content of the newly introduced foreach() ... endforeach; since it would look like the whole function got changed when in fact I only made a very minor change. The function also has a precendent of a non-indented foreach. However, I would anticipate the actual commit might want the indentation, which can be provided.)

(Note: affects, or affected by, #13937)

[coffee2code]

Aforementioned patch.

[nacin]

Duplicate of #13305 which was wontfix'd.

[coffee2code]

A roundabout solution presented there, but so it goes. A straightforward foreach would be more concise:

foreach ( array( 'post', 'page', 'event' ) as $page )
    add_meta_box( 'my-geo', 'Geolocation Info', array( &$this, 'geo_form' ), $page, 'side' );

[hakre]

+1 for wontfix, iterating should be something a developer handles on it's own normally.

[ericlewis]

I think we should do this. Passing arrays of post types is common practice in other APIs.

Think

WP_Query( array( 'post_type' => array( 'post', 'page' ) ) );

which also supports

WP_Query( array( 'post_type' => 'post' ) );

[ericlewis]

Patch needs refresh

[SergeyBiryukov]

A workaround from comment:7:ticket:13305 that does not require a foreach loop:

function your_callback( $post_type ) {
	if ( in_array( $post_type,  array( 'post', 'page' ) ) ) {
		add_meta_box( 'your-id', 'Title', 'your_box_callback', $post_type );
	}
}
add_action( 'add_meta_boxes', 'your_callback' );

[iamfriendly]

Refreshed patch. Now accepts an array of post types or an array of screen objects

[iamfriendly]

Refreshed patch. Now accepts an array of post types or an array of screen objects. Also updated the docblock to reflect that it can accept an array.

[egill]

Personally not a big fan of circular references, would prefer something like:
https://core.trac.wordpress.org/attachment/ticket/15000/15000.3.diff
or even a simple wrapper function for the original function:
https://core.trac.wordpress.org/attachment/ticket/15000/15000.4.diff

Just my $.02 :)

p.s. just a suggestion, haven't tested the patches thoroughly.

[nacin]

I don't mind the circular reference. However, we also need to think about remove_meta_box(), too.

If you are allowed to pass something to add_meta_box() that actually splits into multiple meta boxes due to individual contexts, then remove is going to end up needing to be called for each individual context. Or, it would need to do the same circular reference.

I just think this complicates things. As to whether that outweighs the syntactical sugar, I'm not sure.

[iamfriendly]

Updated patch with changes to remove_meta_box() as well as add_meta_box()

[iamfriendly]

I understand what you mean in terms of pros vs cons of this approach, @nacin.

Personally, I don't mind how this is implemented (with circular references or otherwise), but I think the ease of adding/removing metaboxes from multiple screens at once is useful and, it seems to fall in line with what we do elsewhere.

I've updated the patch with additions to remove_meta_box() (as well as slightly tweaking the docs)

[nacin]

No need to change the spaces in the @param lines — those are accurate as is.

Rather than the ! isset return at the end, I'd just return after the foreach.

We'd also have to make a similar change for remove_meta_box() too. Ideally, we'll add some basic unit tests as well, to tests/phpunit/tests/admin/includesTemplate.php.

[madalin.ungureanu]

Added the same functionality for remove_meta_box() function and made some modiffications in the description of the functions

[mordauk]

15000-tests.diff includes some basic tests for add/remove_meta_box()

[igmoweb]

Unit tests included

[igmoweb]

I've included a couple of tests more for this ticket based on @mordauk ones.

I improved the test_remove_meta_box. When we use remove_meta_box, $wp_meta_boxes['post']['advance']['default']['metabox1'] was set to false but the key 'metabox1' was still present.

I splitted the tests so now we have tests for add_meta_box when $screen cannot be an array and when $screen can be an array of post types.

Sorry for the two EOLs in includesScreen.php as I started to make the tests there by mistake.

[igmoweb]

Unit tets diff extension file fixed

[igmoweb]

Forget about 15000-tests.diff.2​, the extension was wrong, my fault. I included 1500-tests.3.diff

[jared_smith]

This ticket has unit tests, so I'm removing the "needs-unit-tests" keyword.

[meloniq]

Refreshed last one patch (6) to current version of WP (34082). Also moved the Screen ID check out of the loop.

[wonderboymusic]

oops

[iamfriendly]

Would love this getting another pair of eyes so it could be included in 4.4

[DrewAPicture]

Patch needs to be refreshed.

[meloniq]

Refreshed last one patch (6) to current version of WP (rev. 34900). Also moved the Screen ID check out of the loop.

[meloniq]

Refreshed the last one patch as the functions has moved location to template-functions.php

[DrewAPicture]

Combine tests + update docs

[DrewAPicture]

In 34951:

Administration: Add the ability to pass an array of screen IDs to add_meta_box() and remove_meta_box().

The $screen parameter in both functions can now accept a single screen ID, WP_Screen object, or an array of screen IDs.

Adds tests.

Props coffee2code, iamfriendly, madalinungureanu, mordauk, igmoweb, meloniq, DrewAPicture.
See #15000.

[DrewAPicture]

In 34952:

Docs: Normalize documentation spacing in the DocBlocks for add_meta_box() and remove_meta_box() following [34951].

Fixes #15000.