Post Formats: allow filtering content_width per format in wp-admin

[lancewillett]

On front-end a theme can filter $content_width like so:

function twentythirteen_content_width() {
	if ( has_post_format( 'image' ) || has_post_format( 'video' ) ) {
		global $content_width;
		$content_width = 724;
	}
}
add_action( 'init', 'twentythirteen_content_width' );

But ... functions called in wp-admin that use the global $content_width variable won't be changed.

For example, using trunk and Twenty Thirteen theme:

1. Create a new post, set to Image post format
2. Click Add Media to insert an image
3. Upload an image at least 800 px wide
4. You'll see in "Attachment Display Settings" that width for the "large" size to insert to the post is 604 pixels and not 724.

Also, even if detecting a Post Format this way worked correctly on edit, it wouldn't work on first post creation because of how the UI uses JS to switch between the formats.

[lancewillett]

See also #23824 and #23620.

[lancewillett]

This sort-of works:

/**
 * Resizes image restriction in wp-admin Media "large" size for video and image
 * post formats.
 *
 * @param array $dim Dimensions, height x width.
 * @param string $size Image size.
 * @param string $context 'edit' for wp-admin on 'display' for front-end.
 * @return array Resized dimensions to fit Twenty Thirteen's desired widths.
 */
function twentythirteen_test( $dims, $size, $context ) {
	/*
	@todo How to tell from wp-admin if we're in a Video or Image post format?
	And, if you click Add New to make a new post, then click one of the Post Format tabs ...
	how does the Media editor know you've switched?
	*/

	if ( 'large' == $size && 'edit' == $context )
		return array( 724, 724 );
}
add_filter( 'editor_max_image_size', 'twentythirteen_test', 10, 3 );

[lancewillett]

Possibly related to #23198, where TinyMCE uses get_post_format() to add a body class value to the editor.

[DrewAPicture]

This sounds sorta close to #21256. Same basic goal different application.

[kovshenin]

@todo How to tell from wp-admin if we're in a Video or Image post format? And, if you click Add New to make a new post, then click one of the Post Format tabs ... how does the Media editor know you've switched?

We can pass the current selected post format $('#post_format').val() to the query-attachments request that gets fired in media.model.Query.sync and then look for than in $_REQUEST. However, since the media modal saves its state when closed, changing the post format and re-opening media will show the already fetched attachments. We'd need to reset the collection and have it fetch attachments again, which I think is inefficient, but could work.

On the other hand, we can try and bring the content-width-based-on-post-formats logic into the js and resolve all of this client-side.

[lancewillett]

Replying to kovshenin:

On the other hand, we can try and bring the content-width-based-on-post-formats logic into the js and resolve all of this client-side.

A JS-based solution is fine by me.

[nacin]

My comment in #21256 questions whether changing content_width on the fly even makes sense. Just throwing that out there. It seems like content width needs to be separated from embed width.