WordPress "scaled" image feature support, full res URL saved to listings #1973
Description
https://make.wordpress.org/core/2019/10/09/introducing-handling-of-big-images-in-wordpress-5-3/
Introduced in WordPress 5.3, if an image is above a certain "threshold" (width or height), with a default of 2560, WordPress will automatically created a "scaled" version of the image, signified by -scaled being added to the image name, resulting in an image like:
XXX-scaled.jpg
The issue with this is that the value saved for fields on listings, is the actual full res URL of the image, not the "scaled" version of the image. Technically these images still exist (as WordPress just creates an additional "scaled" version of the image), but there's two reasons I wanted to bring this up.
Unable to convert URL to attachment ID
The first issue is that any plugin or theme that attempts to convert the URL to an "attachment post ID" will fail, including calling the internal WordPress core attachment_url_to_postid function, since the value saved to listings is the not the "scaled" version, and when the attachment is inserted, the data is replaced with the URL to the "scaled" image (see below).
Full Res Images are Served on Sites
The other issue is that technically this feature of using "scaled" images will be disregarded by WPJM and the full res images will be served. By supporting the "scaling" feature of WordPress 5.3+, we can make sure that when the user has not specifically disabled the "scaling" feature, that the scaled images will be used -- speeding up site load times, as well as the issue mentioned above.
This only happens when the image is "attached" to a listing, and is triggered by the following:
- WPJM->create_attachment
- wp_generate_attachment_metadata()
- wp_create_image_subsizes()
- _wp_image_meta_replace_original()
- wp_update_attachment_metadata()
It appears that this metadata is passed back to the wp_generate_attachment_metadata function called by WPJM, which includes the metadata saved to the "attachment post" including original_image
So IMO I think to resolve these issues, we should work on adding support for handling this "scaling" of images.
Specifically in the wp-content/plugins/wp-job-manager/includes/forms/class-wp-job-manager-form-submit-job.php file where we call wp_generate_attachment_metadata we can check the data returned to see if the image was in fact "scaled", we would just have to figure out how we would then update the data in $values to reflect this.
The problem is that create_attachment is called after the metadata is updated/set in update_job_data, so we would essentially have to move things around a bit, or come up with the best way to handle this.
What are your thoughts @jom ?