- 1 Functions by category
- 1.1 Post, Custom Post Type, Page, Attachment and Bookmarks Functions
- 1.2 Category, Tag and Taxonomy Functions
- 1.3 User and Author Functions
- 1.4 Feed Functions
- 1.5 HTTP API Functions
- 1.6 Comment, Ping, and Trackback Functions
- 1.7 Action, Filter, and Plugin Functions
- 1.8 Theme-Related Functions
- 1.9 Formatting Functions
- 1.10 Miscellaneous Functions
- 1.11 Multisite functions
- 2 Official and Unofficial References
The files of WordPress define many useful PHP functions. Some of the functions, known as Template Tags, are defined especially for use in WordPress Themes. There are also some functions related to actions and filters (the Plugin API), which are therefore used primarily for developing Plugins. The rest are used to create the core WordPress functionality.
Many of the core WordPress functions are useful to Plugin and Theme developers. So, this article lists most of the core functions, excluding Template Tags. At the bottom of the page, there is a section listing other resources for finding information about WordPress functions. In addition to this information, the WordPress phpdoc site details all the WordPress functions by version since 2.6.1.
Functions by category
Official and Unofficial References
- WordPress.org PHPDoc - Nearly all the functions in WordPress have "PHPDoc" headers. This site shows all the PHPDoc.
- Trac Browser - WordPress source code. Choose 'Tags' to find a specific version source code, or 'Trunk' to see the latest version source code.
- PHPXref for WordPress - Cross reference of WordPress files, functions, and variables, which seems to point to the latest released version. This redalt.com PHPXref site has the bleeding-edge Trunk version, as well as 1.5 and 2.0, but the Trunk version may not be updating any more. So, there is now a new Trunk Xref site on ftwr.co.uk available.
- WordPress Function History Table - List each WordPress function with including the version it was introduced in or dropped in. PlanetOzh recommends: "see related WordPress Functions Implementation History Tool for more information (and for a more usable tool)"
- WordPress Variable Report - A list of WordPress functions, listing what version of PHP every function requires (and if there's a compatible function available), what varables/arguments in functions are unused, and what functions/variables each class contains (and their default values).
- WordPress Hooks Table - A list of WordPress actions and filters, cross-referenced to the files they are in