Hooks Reference

Hooks Reference

Every action and filter PhotoPress provides, every WordPress core hook it uses, and the documented hooks and functions of other plugins it calls. Code links point to the 2.0.0 code (commit b6499f6).

PhotoPress uses documented public hooks and functions of WordPress and of other plugins. It does not read other plugins' tables or internal classes. Two exceptions: WP Offload Media documents only its settings, so PhotoPress uses its other hooks as its own add-ons do (Offload Media and CDN). Relevanssi has no filter for the post types and taxonomies it indexes, so PhotoPress saves those Relevanssi settings as its Indexing tab does, and removes only what it added (Image Search).

Hooks PhotoPress provides

Actions

Action	Arguments	Fires	Code
photopress_post_changed	int $id, array $context: files (URLs of files that changed), content (true when stored content was rewritten in place), gallery (true when the images its gallery shows changed)	What a post or image shows changed without WordPress saving an edit. Used by the page cache and search index integrations.	GalleryAdd.php#L801
photopress_image_terms_changed	int $id, array $context: archives (archive URLs of the terms involved, before and after a rename), terms (the terms the image joined, left or lost, as <taxonomy>:<term ID>, absent from the term-change job), job (true when fired by the term-change job)	An image joined or left a term of an image taxonomy, or one of its terms was renamed or deleted.	TermChanges.php#L101
photopress_term_images_changed	array $images: terms (term_taxonomy_ids) or images (IDs)	A term with more than 25 images was renamed or deleted.	TermChanges.php#L177
photopress_attachment_file_replaced	int $id, string[] $replacements (old upload-relative paths mapped to new), int[] $rewritten (posts whose links were rewritten), array $options (reprocess_metadata)	An image was given a new file through PhotoPress or Enable Media Replace.	MediaRest.php#L388
photopress_attachment_files_removed	int $id, string[] $urls	A replacement deleted files the new file does not have.	MediaRest.php#L364
photopress_image_files_rewritten	int $id	An image's files were written again under the same URLs: every size made again by the regenerate job, or the license written by the license job.	images.php#L456, metadata.php#L1674
photopress_image_sizes_regenerated	array $job	The images.regenerate job finished. Files changed under the same URLs.	images.php#L675
photopress_job_batch_started	array $job	A batch of a background job starts in this request.	Jobs.php#L311
photopress_job_batch_ended	array $job (status running, done or cancelled)	A batch ends in this request.	Jobs.php#L376
photopress_job_ended	array $job	A job is done or cancelled.	Jobs.php#L391

Filters

Filter	Value and arguments	Purpose	Code
photopress_job_max_load	float $max (default 0.7 × processors)	Load average above which paced jobs wait.	Jobs.php#L429
photopress_job_min_memory	int $bytes (default 300 MB)	Available memory below which paced jobs wait.	Jobs.php#L419
photopress_imagick_limits	array $limits (memory, map in bytes; thread in the job), bool $job	ImageMagick resource limits while WordPress makes image sizes. A value of 0 or less leaves that limit unchanged.	images.php#L613
photopress_term_images_job	bool $needed	Whether the images of a renamed or deleted term with many images are processed one by one in a job.	TermChanges.php#L179
photopress_replace_file_args	array $args	Arguments of POST /photopress/v1/media/{id}/file.	MediaRest.php#L140
photopress_replace_file_response	array $data, int $id, WP_REST_Request $request	Response of a file replacement.	MediaRest.php#L457
photopress_attachment_description	string|null $description, int $id, string $file	Description given to an image whose file is replaced.	MediaRest.php#L726
photopress_metadata_tag_name	string $name	Alias of a metadata tag name before lookup.	XmpReader.php#L167
photopress_metadata_tag_value	mixed $value, string $name, array $all_xmp	Value of a metadata tag.	XmpReader.php#L177
photopress/taxonomies/defaultDefinitions	array $taxonomies	Default image taxonomy definitions for a new site.	metadata.php#L1250

JavaScript events and properties

Name	Kind	Details	Code
pp-slideshow-opened	DOM event	Dispatched on #lightbox-gallery when the full-screen slideshow opens. Bubbles.	lightbox.js#L210
pp-slideshow-closed	DOM event	Dispatched on #lightbox-gallery when it closes. Bubbles.	lightbox.js#L224
photopress-slideshow-change	DOM event	Dispatched on a slideshow's .photopress-gallery-slideshow element when the current image changes, and once when it starts. event.detail.index is the position, from 0. Does not bubble.	slideshow.js#L286
element.photopressSlideshow	property	Set on each Gallery Slideshow block's root element: show( index ), next(), prev(), current(), destroy().	gallery-slideshow.js#L16

Action Scheduler hooks

PhotoPress schedules these actions in the Action Scheduler group photopress. They are internal. Do not schedule them yourself.

Hook	Argument	Runs
photopress_job_batch	job ID	One batch of a background job.
photopress_cdn_invalidate	none	Sends queued CloudFront invalidations.
photopress_offload_delete_objects	bucket, region, keys, attempt	Deletes replaced files from the bucket.
photopress_replace_settle	attachment ID	Undoes a file replacement that did not finish.
photopress_gallery_remove_retry	post ID, image IDs, time of the deletion	Removes deleted images from a post that was open in the editor. If the post is still open, it reschedules itself, for up to a day.

WordPress core hooks PhotoPress uses

Hook	Type	Code	Purpose
plugins_loaded	action	photopress.php#L52, Scheduler.php#L47	Starts the plugin and decides whether to load Action Scheduler.
init	action	class-module.php#L50	Registers taxonomies, blocks, scripts and module hooks.
wp_loaded	action	metadata.php#L480, PageCache.php#L85, GalleryUpgrade.php#L39	Rebuilds rewrite rules when taxonomy URLs change. Empties the page cache once after an update. Starts the gallery upgrade job once per site.
admin_init, rest_api_init	action	class-module.php#L220, ImageSearch.php#L109	Registers settings (register_setting) and REST routes. With Relevanssi active, syncs its indexing settings with Images in search results.
admin_menu	action	class-module.php#L223	Adds the PhotoPress › Settings menu.
admin_enqueue_scripts	action	base.php#L15	Loads the settings app on PhotoPress screens only.
enqueue_block_editor_assets, enqueue_block_assets	action	gallery.php#L68, class-pp-framework.php#L146	Editor scripts and the shared block styles.
register_block_type_args	filter	gallery.php#L72	Adds PhotoPress attributes to core/gallery.
render_block_data	filter	gallery.php#L73	Loads a gallery's images in one query before it renders.
render_block_{$name} (core/gallery)	filter	gallery.php#L74	Applies layouts. Hides a gallery shown by a Gallery Slideshow block.
render_block	filter	slideshow.php#L29, metadata.php#L117	Marks slideshow galleries. Adds license JSON-LD.
pre_render_block	filter	ImageTemplates.php#L41, LegacyChildPages.php#L23	Renders Taxonomy and Child Pages Galleries. Renders a legacy Child Pages block as a Child Pages Gallery.
taxonomy_template_hierarchy, search_template_hierarchy	filter	ImageTemplates.php#L46, ImageSearch.php#L60	Offers the Image Archives and Image Search templates.
wp_footer	action	slideshow.php#L78, metadata.php#L124	Prints the full-screen slideshow container, and license JSON-LD for archives and image pages.
pre_get_posts	action	metadata.php#L166, ImageSearch.php#L58	Includes images in taxonomy archives and search results.
posts_where, posts_search	filter	metadata.php#L137, ImageSearch.php#L59	Limits queries to public images. Searches alt text and terms.
pre_option_{$option} (wp_attachment_pages_enabled)	filter	search.php#L79	The Attachment pages switch.
attachment_link	filter	search.php#L89	Links to the file when attachment pages are off.
add_attachment	action	metadata.php#L62, GalleryAdd.php#L67, TaxonomyGalleryPages.php#L50	Reads metadata into terms, alt text and description. Adds an upload to a gallery. Announces posts whose Taxonomy Gallery shows the latest images.
attachment_updated	action	PageCache.php#L83, TaxonomyGalleryPages.php#L51	Purges an edited image. Announces posts whose Taxonomy Gallery may show it.
delete_attachment	action	GalleryRemove.php#L51, TaxonomyGalleryPages.php#L52	Removes a deleted image from galleries. Announces posts whose Taxonomy Gallery may show it.
attachment_fields_to_edit	filter	metadata.php#L121	Shows a license write failure on the image.
wp_read_image_metadata	filter	metadata.php#L46	Reads the title and caption from XMP, and camera and exposure details.
pre_move_uploaded_file	filter	metadata.php#L112	Embeds the license before the upload is moved into place.
image_strip_meta	filter	metadata.php#L127	Whether resized images keep their metadata, from the metadata settings.
max_srcset_image_width	filter	metadata.php#L43	Allows sizes up to 3000 px in srcset.
wp_editor_set_quality	filter	images.php#L55	JPEG and WebP quality.
intermediate_image_sizes_advanced	filter	images.php#L56	Sizes turned off are not made.
wp_generate_attachment_metadata	filter	images.php#L58	Records the quality an image's sizes were made at.
wp_image_editors	filter	images.php#L59	Applies ImageMagick limits.
wp_get_missing_image_subsizes	filter	images.php#L479	Makes only the sizes a regenerate needs.
update_post_metadata, add_post_metadata, update_attached_file, image_make_intermediate_size	filter	images.php#L525	Held back during a regenerate, so the image is saved once all sizes exist.
upload_dir	filter	MediaRest.php#L310	Keeps a replacement file in the image's folder.
added_term_relationship, deleted_term_relationships, edit_terms, edited_term, pre_delete_term, delete_term	action	TermChanges.php#L55	Turns term changes into photopress_image_terms_changed and photopress_term_images_changed.
wp_after_insert_post, deleted_post	action	ChildPagesGallery.php#L32, TaxonomyGalleryPages.php#L48	Purges a parent page when its child pages change. Records a saved post's Taxonomy Galleries.
shutdown	action	GalleryRemove.php#L75, ImageSearch.php#L559	Batched gallery edits and search re-indexing at the end of the request.
rest_endpoints, rest_attachment_item_schema, rest_post_dispatch, rest_term_search_query, rest_prepare_attachment, rest_attachment_query, rest_queried_resource_route	filter	ImageTaxonomyRest.php#L62	Keeps image taxonomies out of anonymous REST responses.
rest_request_after_callbacks	filter	GalleryAdd.php#L66	Adds an uploaded image to its gallery once its sizes exist.
rest_namespace_index	filter	MediaRest.php#L81	WordPress and PhotoPress versions, for users who can upload.
widgets_init, widget_types_to_hide_from_legacy_widget_block	action, filter	metadata.php#L134	Registers the legacy widgets and hides them from the block widget inserter.
wp_sitemaps_post_types, wp_sitemaps_posts_query_args	filter	CoreSitemap.php#L22	Image pages in WordPress's sitemap.

Core functions PhotoPress depends on include register_taxonomy, register_block_type, wp_register_block_metadata_collection (WordPress 6.7+, when present), register_setting, register_rest_route, wp_set_object_terms, wp_generate_attachment_metadata, wp_update_attachment_metadata and flush_rewrite_rules.

Third-party hooks and functions

Each integration is inactive when its plugin is inactive.

Plugin	Hooks and functions used	Code	Wiki
Action Scheduler (bundled)	as_enqueue_async_action, as_schedule_single_action, as_unschedule_all_actions, as_get_scheduled_actions, as_has_scheduled_action; action action_scheduler_after_process_queue	Scheduler.php, Jobs.php	Background Jobs
Proxy Cache Purge	filters varnish_http_purge_events, varnish_http_purge_events_full, varnish_http_purge_valid_post_statuses, vhp_purge_urls; fires the events photopress_purge_post and photopress_purge_all registered through them	PageCache.php#L75	Page Cache
Relevanssi	filters relevanssi_index_custom_fields, relevanssi_hits_filter; its settings relevanssi_index_post_types, relevanssi_index_taxonomies_list and relevanssi_index_image_files, read and saved as its Indexing tab does; functions relevanssi_do_query, relevanssi_index_doc, relevanssi_get_custom_fields	Relevanssi.php, ImageSearch.php	Image Search
Jetpack	filters jetpack_page_sitemap_other_urls, jetpack_sitemap_image_skip_post, jetpack_sitemap_image_sitemap_item	JetpackSitemap.php#L28	Sitemaps
Yoast SEO	filters wpseo_sitemap_exclude_post_type, wpseo_sitemap_exclude_taxonomy, wpseo_sitemap_urlimages_term, wpseo_sitemaps_providers; interface WPSEO_Sitemap_Provider; WPSEO_Post_Type::is_post_type_accessible, is_post_type_indexable	YoastSitemap.php#L27, YoastImagesSitemap.php	Sitemaps
WP Offload Media	its AS3CF_SETTINGS keys (documented); action as3cf_init, filters as3cf_pre_update_attachment_metadata and as3cf_object_meta, get_setting() and its bundled AWS SDK, used as its own add-ons use them	OffloadMedia.php#L35	Offload Media and CDN
Enable Media Replace	action enable-media-replace-upload-done	EnableMediaReplace.php#L26	Replacing Image Files