Lifecycle and Data

Lifecycle and Data

What PhotoPress does when it is activated, deactivated, updated and deleted, and every option, meta key and transient it stores. For developers and site owners who need to know what PhotoPress leaves in the database.

Requirements

• WordPress 6.6 or later (Requires at least in README.txt).
• Version 2.0.0 (photopress.php). PHOTOPRESS_CORE_VERSION is read from that header.

How it works

Activation

photopress_plugin::activate() deletes the option photopress_taxonomy_rewrites. On the next request the metadata module finds no record of the image taxonomies' rewrite rules and flushes the rules at wp_loaded, after every plugin has registered its post types and taxonomies (code).

PhotoPress's own code creates no database tables.

Deactivation

photopress_plugin::deactivate():

1. Scheduler::deactivate() unschedules every Action Scheduler action in the group photopress, deletes photopress_scheduled, and, if no other plugin had loaded Action Scheduler, clears its every-minute WP-Cron event action_scheduler_run_queue.
2. Deletes photopress_taxonomy_rewrites and rewrite_rules. WordPress builds the rules again on the next request, without the image taxonomies.

Unfinished jobs are kept. When PhotoPress is activated again they get a new batch from recovery. See Background Jobs.

Updates

PhotoPress has no upgrade routine and no stored schema version. Changes between versions are handled where the data is read:

On	What happens	Code
The first request after an update (wp_loaded)	If photopress_version differs from the running version, it is updated and, while Proxy Cache Purge is active, the page cache is emptied. Pages cached by the earlier version do not then ask for scripts and styles this version lacks.	PageCache.php#L334
init, while the Metadata settings lack description_enable	Sets description_enable to true where a description template is set, false otherwise. Before the switch existed, the template alone turned the description on.	metadata.php#L319
Reading settings in the admin or REST API	Keys that are no longer fields are dropped. Fields added since get their defaults. See Settings storage.	class-settings.php#L348
Each request, while photopress_scheduled is missing	Counted as pending, so Action Scheduler loads and runs any queued work.	Scheduler.php#L85
Regenerating an image	_photopress_sizes_signature (1.9.0) is deleted.	images.php#L445

Uninstall

Deleting PhotoPress from Plugins runs uninstall.php. On multisite it runs for every site of the network (get_sites() with no limit, then switch_to_blog()).

Deleted on each site:

• the options listed in PHOTOPRESS_UNINSTALL_OPTIONS and the transients in PHOTOPRESS_UNINSTALL_TRANSIENTS;
• every option starting with photopress_core_ (module settings), photopress_job_ (jobs, their locks and start locks) or photopress_cdn_job_ (paths jobs rewrote);
• the random-gallery transients photopress_gallery_ids_*;
• the post meta _photopress_gallery_terms (delete_post_meta_by_key());
• Action Scheduler's WP-Cron event, unless another active plugin's copy of Action Scheduler is loaded.

Kept:

• images, their files, and image taxonomy terms;
• post meta: _photopress_quality, _photopress_sizes_signature, _photopress_replaced_at, _photopress_replace_restore, _photopress_license_error;
• metadata PhotoPress wrote into WordPress's own fields: alt text, captions, descriptions, and licensing written into image files;
• the photopress-tmp folder in uploads;
• other PhotoPress plugins' settings (photopress_seo_*, photopress_pro_*).

Direct-access guards

Every PHP file outside tests/ and vendor/ stops when loaded outside WordPress. The others check ABSPATH: all but src/init.php start with defined( 'ABSPATH' ) || exit;. photopress.php checks WPINC. uninstall.php checks WP_UNINSTALL_PLUGIN. The photopress-tmp folder gets an .htaccess with Require all denied. See Image Sizes.

WordPress integration

Hook	Type	Code	Purpose
register_activation_hook	function	photopress.php#L54	Activation.
register_deactivation_hook	function	photopress.php#L55	Deactivation.
plugins_loaded	action	photopress.php#L52	Priority 1: builds the package and its modules (base, gallery, slideshow, metadata, search, images, media).
init	action	class-module.php#L50	Priority 0: each module reads its option definitions and adds its hooks.
admin_init, rest_api_init	action	class-module.php#L220	Registers each module's setting.
option_{$option}	filter	class-settings.php#L336	asFields: the stored settings as exactly their fields.
wp_loaded	action	PageCache.php#L85	Empties the page cache after an update.

Settings storage and /wp/v2/settings

Each module's settings are one option, photopress_core_<module>, an array keyed by field (class-util.php). The settings tabs read and write them through core's /wp/v2/settings, which requires manage_options.

registerSettings() calls register_setting() with:

• show_in_rest: an object schema with one property per field and additionalProperties: false. The REST name is the option name.
• default: every field's default.
• sanitize_callback: sanitizeOptions().

Field types map to the schema and to sanitizing as follows (code):

Field type	REST schema	Saved as
boolean	boolean	(bool)
integer	integer, minimum 0	max( 0, (int) )
select	string, enum of its options	The value, if allowed. Otherwise the stored value is kept.
url	string	esc_url_raw()
none (image taxonomies list)	array of objects	Each entry cleaned: id by sanitize_key(), at most 32 characters, prefixed pp_ if it is a core taxonomy name, made unique with a suffix.
anything else (text, comma-separated list)	string	sanitize_text_field()

sanitizeOptions() also drops keys that are not fields, and keeps the stored value of a field the request leaves out.

asFields() filters the option on read wherever the setting is registered (admin and REST requests). It returns only current fields, with defaults for fields the stored value lacks. A stored key that is no longer a field would otherwise make the settings endpoint return null for the whole option.

On the front end, PhotoPress reads a setting as its stored value, or the module's default when the key is missing (pp_api::getOption()).

Options

Option	Purpose	Written by
photopress_core_<module>	A module's settings.	Settings tabs
photopress_jobs	IDs of the last 20 jobs.	Background Jobs
photopress_job_<id>	A job's state.	Background Jobs
photopress_job_<id>_lock	A job's batch lock.	Background Jobs
photopress_job_start_<md5>	A job type's start lock.	Background Jobs
photopress_scheduled	pending or idle: whether PhotoPress has Action Scheduler work. Autoloaded.	Scheduler.php#L35
photopress_reprocess_queue	metadata.reprocess runs waiting for the running one.	metadata module
photopress_search_term_changes	Terms and images waiting for the running search.terms job.	search module
photopress_purge_after_jobs	Jobs whose batches held back page cache purges. The cache is emptied when each ends.	PageCache.php#L65
photopress_version	The version the page cache was last emptied for. Autoloaded.	PageCache.php#L53
photopress_taxonomy_rewrites	Hash of the image taxonomies' rewrite rules last built.	metadata module
photopress_flush_rewrite_rules	Not written by 2.0.0. Deleted when the rules are rebuilt, and on uninstall.	metadata module
photopress_old_people	yes or no: whether the site has terms in photos_people, the People parent keyword of defaults before 2.0.	metadata.php#L1166
photopress_images_assumed_quality	The quality assumed for images without _photopress_quality.	Image Sizes
photopress_sitemap_seen	When each sitemap was last built with PhotoPress's hooks, by name.	ImageSitemap.php#L31
photopress_cdn_pending	Paths waiting for a CloudFront invalidation.	Offload Media and CDN
photopress_cdn_last	The last invalidation's result.	Offload Media and CDN
photopress_cdn_job_<id>	Paths a running job rewrote, to clear from CloudFront when it ends.	Offload Media and CDN
photopress_gallery_upgrade	The version of the gallery upgrade job started on this site. Autoloaded.	Child Pages Gallery

Transients

Transient	Lifetime	Purpose
photopress_cdn_distribution	1 day	The CloudFront distribution found for the delivery domain.
photopress_aws_role_credentials	Until 5 minutes before they expire, or 1 hour when there are none	The EC2 instance role's credentials.
photopress_cdn_all_cleared	10 minutes	Limits Clear the whole CDN.
photopress_gallery_ids_<md5>	10 minutes	The IDs a random-order gallery may show, shuffled per view (code).

Post meta

All on attachments, except _photopress_gallery_terms.

Meta key	Purpose
_photopress_gallery_terms	On posts: one row per Taxonomy Gallery that chooses its images, <taxonomy>:<term ID> or latest, for page cache purges. See Taxonomy Gallery. Deleted on uninstall.
_photopress_quality	The quality the image's sizes were made at. See Image Sizes.
_photopress_sizes_signature	From 1.9.0. Not read. Deleted when the image is regenerated.
_photopress_replaced_at	When the image's file was last replaced. See Replacing Image Files.
_photopress_replace_restore	The restore record of a replacement under way.
_photopress_license_error	Why the license could not be written into the image's file: message, time. Deleted once it is written.

PhotoPress also writes core fields: _wp_attachment_image_alt, the title, caption and description, image taxonomy terms, and _wp_attached_file / _wp_attachment_metadata when it remakes sizes or replaces a file.

Action Scheduler

Actions in the group photopress (photopress_job_batch, photopress_cdn_invalidate, photopress_offload_delete_objects, photopress_replace_settle, photopress_gallery_remove_retry) are stored in Action Scheduler's tables. Deactivation unschedules them. Uninstall does not touch Action Scheduler's tables, which other plugins may share.

Third-party integrations

Proxy Cache Purge. After an update, the page cache is emptied once through PhotoPress's photopress_purge_all event, registered with varnish_http_purge_events and varnish_http_purge_events_full. Without Proxy Cache Purge, photopress_version is still updated and nothing is purged.

Action Scheduler (bundled). See Background Jobs.

Limits, quirks and known issues

• Uninstall removes no post meta other than _photopress_gallery_terms, and no terms or files. Their removal is left to you.
• The description_enable check runs on init on every request. It writes only when saved Metadata settings lack the key.
• photopress_old_people is worked out once and not checked again.
• Deactivation deletes rewrite_rules, which every plugin's rules share. WordPress builds them all again on the next request.

Related

• Background Jobs
• Image Sizes
• Offload Media and CDN
• Replacing Image Files
• Page Cache
• Hooks Reference