Filters and actions have been the basis of WordPress' plugin functionality since time immemorial, they've always been a reliable method for acting upon the current state of WordPress, and will continue to be so.
Over the years, however, edge cases have cropped up. Particularly when it comes to recursively executing hooks, or a hook adding and removing itself, the existing implementation struggled to keep up with more complex use cases.
And so, we introduce `WP_Hook`. By changing `$wp_filter` from an array of arrays, to an array of objects, we reduce the complexity of the hook handling code, as the processing code (see `::apply_filters()`) only needs to be aware of itself, rather than the state of all hooks. At the same time, we're able te handle more complex use cases, as the object can more easily keep track of its own state than an array ever could.
Props jbrinley for the original architecture and design of this patch.
Props SergeyBiryukov, cheeserolls, Denis-de-Bernardy, leewillis77, wonderboymusic, nacin, jorbin, DrewAPicture, ocean90, dougwollison, khag7, pento, noplanman and aaroncampbell for their testing, suggestions, contributions, patch maintenance, cajoling and patience as we got through this.
Fixes#17817.
Built from https://develop.svn.wordpress.org/trunk@38571
git-svn-id: http://core.svn.wordpress.org/trunk@38514 1a063a9b-81f0-0310-95a4-ce76da25c4cd
First added in [37588] and later modified in [38224], the idea was to ensure that filters/actions added before `advance-cache.php` would not disappear if `advance-cache.php` overloaded the filters/actions with code such as `$wp_filter = array()`. This is an edge case and one that there is no documented case of existing.
This restores the behavior from WordPress 4.5 and before. It is strongly encouraged that developers using `advance-cache.php` to use the Plugins API that is available before the loading of `advance-cache.php` rather than directly interacting with any of the globals.
Props azaozz, jorbin, dd32 for review, pento for review, westi for investigation, ipstenu for research.
See #36819.
Built from https://develop.svn.wordpress.org/trunk@38251
git-svn-id: http://core.svn.wordpress.org/trunk@38192 1a063a9b-81f0-0310-95a4-ce76da25c4cd
[37588] added methods to backup the plugin globals, for ensuring that advanced cache drop-ins don't overwrite hooks that've been added earlier in the load process.
The method for restoring the plugin globals wasn't compatible with the implementation of `WP_Hook` in #17817. `WP_Hook` implements `ArrayAccess`, so `_restore_plugin_globals()` was treating it as an array, and inadvertantly overwriting the `WP_Hook` object with a plain array.
To avoid having to re-write this code as part of #17817, we now use `add_filter()` to restore any hooks that were added by cache drop-ins, which `WP_Hook` correctly supports.
Props pento, jorbin.
See #36819.
Built from https://develop.svn.wordpress.org/trunk@38223
git-svn-id: http://core.svn.wordpress.org/trunk@38164 1a063a9b-81f0-0310-95a4-ce76da25c4cd
In order to allow non-web initializations of WordPress (such as through wp-cli) to modify things like the check for maintenance mode, plugins.php and the associated functions must be available much earlier. The use of these functions earlier than the loading of plugins is not recommended in most use cases.
Fixes#36819. See #34936.
Props jorbin, danielbachhuber for documentation.
Built from https://develop.svn.wordpress.org/trunk@37588
git-svn-id: http://core.svn.wordpress.org/trunk@37556 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Known functions, classes, and methods are now auto-linked in Code Reference pages following #meta1483.
Note: Hook references are still linked via inline `@see` tags due to the unlikelihood of reliably matching for known hooks based on a RegEx pattern.
See #32246.
Built from https://develop.svn.wordpress.org/trunk@37342
git-svn-id: http://core.svn.wordpress.org/trunk@37308 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Affects DocBlocks for the following core elements:
* Markdown-indent a code snippet in the description for `wp_salt()`
* Backtick-escape inline code in the return description for `get_avatar()`
* Various markdown formatting in the description for `add_filter()`
* Markdown-indent a code snippet in the description for `apply_filters()`
* Backtick-escape inline code in the `@see` description for `apply_filters_ref_array()`
* Backtick-escape inline code in the description for `do_action()`
* Backtick-escape variables in the parameter and return descriptions for `do_action_ref_array()`
* Various markdown formatting in the description for `get_plugin_data()`
Props rarst.
See #30473.
Built from https://develop.svn.wordpress.org/trunk@30544
git-svn-id: http://core.svn.wordpress.org/trunk@30533 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Per our inline documentation standards, no further use of the `@uses` tag is recommended as used and used-by relationships can be derived through other means. This removes most uses of the tag in core documentation, with remaining tags to be converted to `@global` or `@see` as they apply.
Fixes#30191.
Built from https://develop.svn.wordpress.org/trunk@30105
git-svn-id: http://core.svn.wordpress.org/trunk@30105 1a063a9b-81f0-0310-95a4-ce76da25c4cd
did_action() returns true the moment a hook is initially run, leaving you no way to tell if the hook is still in progress. Hooks can be nested and this checks the entire stack, versus current_filter() which only identifies the final hook in the stack. This commit also introduces current_action() for parity.
To tell if a hook has completed, one can use did_action() and ! doing_action() together.
The functions do not require an argument. In that situation, they indicate whether the stack is empty.
props ericmann for the initial unit tests.
fixes#14994.
Built from https://develop.svn.wordpress.org/trunk@27294
git-svn-id: http://core.svn.wordpress.org/trunk@27150 1a063a9b-81f0-0310-95a4-ce76da25c4cd
