Add ability to apply image edits to custom image sizes

[silb3r]

This patch allows developers to add custom image sizes to the "Edit Image" -> "Apply changes to:" setting so that image edits may be set to only affect a custom image size.

This can now be accomplished using the 'edit_custom_thumbnail_sizes' filter and passing it an array of 'Label' => 'size' elements.

And this is my first contribution so please go easy on me (administratively speaking)!

[silb3r]

Add ability to apply image edits to custom image sizes only

[SergeyBiryukov]

#22990 was marked as a duplicate.

[WraithKenny]

This would certainly fill a hole in the incomplete edit feature.

[joedolson]

Updated patch fixes some issues with inappropriate use of translation functions, adds escaping, and updates the patch.

The original patch required a user to return an array of image sizes to use in custom size editing; I changed that so a value of 'true' can return the value of get_intermediate_image_sizes(), though it can be overridden to customize the values.

Not requiring a custom array does mean that we don't have any custom labels for the sizes, which was a benefit to passing a custom array; but also makes it harder to turn on.

[joedolson]

Update & refresh patch.

[joedolson]

To test:

• This patch does not enable the feature; it adds a filter to enable it. Before applying the patch, you can switch the value $edit_custom_sizes = false; to true.
• Go to edit a media item and select an option to apply sizes to.
• Verify that the edits were applied to the expected sizes.

[costdev]

Test Report

Environment

• Server: Apache (Linux)
• WordPress: 6.0-alpha-52448-src
• Browser: Chrome 100.0.4896.75
• OS: Windows 10
• Theme: Twenty Twenty
• Plugins:
  • Test 'edit_custom_thumbnail_sizes' filter. 1.0.0

Steps

1. Apply 28277.2.diff.
2. Add the following to wp-content/plugins/test-edit-custom-thumbnail-sizes/test-edit-custom-thumbnail-sizes.php:

<?php

/**
 * Plugin Name: Test 'edit_custom_thumbnail_sizes' filter.
 * Description: A test for the 'edit_custom_thumbnail_sizes' filter.
 * Author:      WordPress Core Contributors
 * Version:     1.0.0
 */

add_action(
        'after_setup_theme',
        function() {
                add_image_size( 'my-custom-size', 123, 123 );
                add_filter( 'edit_custom_thumbnail_sizes', '__return_true' );

                if ( ! is_admin() ) {
                        $latest_image = new WP_Query(
                                array(
                                        'post_type'      => 'attachment',
                                        'post_status'    => 'any',
                                        'posts_per_page' => 1,
                                )
                        );
                        echo wp_get_attachment_image( $latest_image->posts[0]->ID, 'my-custom-size' );
                        echo wp_get_attachment_image( $latest_image->posts[0]->ID, 'thumbnail' );
                }
        }
);

3. Navigate to Plugins > Installed Plugins.
4. Activate the Test 'edit_custom_thumbnail_sizes' filter. plugin.
5. Navigate to Media > Add New.
6. Upload a new image.
7. Click Edit.
8. Click Edit Image. See that the my-custom-size is shown under the Thumbnail Settings > Apply changes to section. ✅
9. Select my-custom-size under Thumbnail Settings > Apply changes to section.
10. At the top, click the Flip Vertically button.
11. Click Save.
12. Click Update.
13. Navigate to the frontend. See that two images are shown:
    • The my-custom-size size, flipped vertically. ✅
    • The thumbnail size, not flipped vertically. ✅
14. In the plugin file from step 2, change __return_true to __return_false.
15. Navigate to Media > Library.
16. Click Edit on the image you uploaded.
17. Click Edit Image. See that my-custom-size is not shown under the Thumbnail Settings > Apply changes to section. ✅

Results

1. 28277.2.diff works as expected.

Notes

• Adding for commit consideration.

[joedolson]

Thanks, @costdev! I'm going to go ahead and commit this. I'm still not 100% thrilled with the use of size keys for labels, but I think that can be tweaked during beta, if it's seen as necessary. Since this is all behind a filter, anyway, it's not going to have a profound impact on most users.

[joedolson]

In 53161:

Media: Enable edits to custom image sizes.

Add a filter edit_custom_thumbnail_sizes to allow users to enable editing individual custom image sizes.

Props silb3r, joedolson, costdev.
Fixes #28277.