Hi. I’m developing a plugin to customize what metadata is used to generate the alt-text for images on Omeka in order to enhance Omeka’s accessibility. With the file_markup filter, it was simple to take the $html, replace the alt-text section of the string, and return it with the changes. However, the changes are only effective on file/show pages because that is the only place file_markup() is called.
The function item_image is used to generate the alt text for almost all image items. It calls image_tag() directly in FileMarkup.php instead of calling the file_markup() function, so the changes made to the $html my file_markup filter are bypassed.
Are there any methods to use a filter to modify the html code returned by image_tag() in FileMarkup.php, any suggestions to modifying the data image_tag() returns through a plugin, or any other approaches I could take to customize the alt-text for images?