Problem/Motivation
It would be useful to be able to customize media mappings to allow other modules to modify the structures.
A good use case would be ckeditor_media_resize that can resize an image via ckeditor.
[[{"fid": "1146","view_mode": "default","fields": {"format": "default","field_file_image_alt_text[und][0][value]": false,"field_file_image_title_text[und][0][value]": false,},"type": "media","link_text": null,"field_deltas": {"1": {"format": "default","field_file_image_alt_text[und][0][value]": false,"field_file_image_title_text[und][0][value]": false,}},"attributes": {"height": 323,"width": 400,"style": "height: 283px; width: 350px; margin: 5px 8px; float: right;","class": "media-element file-default","data-delta": "1"}}]]
With ckeditor_media_resize this might be something like this:
<drupal-media data-entity-type="media" data-entity-uuid="00517131-5632-4716-a835-3e30f3200517" style="width:400px;" class="media-embed-resized">
Steps to reproduce
Proposed resolution
At the end of MediaWysiwygFilter::transform() initiate a hook that allows the attributes to be modified, e.g.:
hook_media_wysiwyg_filter_alter($embed_metadata, $source_attributes);
?>
Remaining tasks
Build the hook.
API changes
A new hook is available called hook_media_wysiwyg_filter_alter().