Plugins, Hooks (category)
| activate_plugins() | Activates the specified plugins. |
| add_screen_option() | Register and configure an admin screen option |
| content_url() | Retrieves the URL to the content directory. |
| deactivate_plugins() | Deactivate a single plugin or multiple plugins. |
| get_file_data() | Gets the file data specified in the PHP comments of the file. |
| get_plugin_data() | Parses the plugin contents to retrieve plugin's metadata. |
| get_plugins() | Gets all plugins data (active and inactive): file, name, author, etc. Works with the plugins directory. |
| is_plugin_active() | Determines whether a plugin is active. Works in the dashboard only. Conditional tag. |
| plugin_basename() | Gets the basename of a plugin. |
| plugin_dir_path() | Get the filesystem directory path (with trailing slash) for the plugin __FILE__ passed in. |
| plugin_dir_url() | Get the URL directory path (with trailing slash) for the plugin __FILE__ passed in. |
| plugins_url() | Retrieves a URL within the plugins or mu-plugins directory. |
| register_activation_hook() | Set the activation hook for a plugin. |
| register_deactivation_hook() | Set the deactivation hook for a plugin. |
| register_uninstall_hook() | Set the uninstallation hook for a plugin. |
| validate_plugin_requirements() | Validates the plugin requirements for WordPress version and PHP version. |
| wp_get_active_and_valid_plugins() | Retrieve an array of active and valid plugin files. |
Hooks (actions, filters)
| add_action() | Hooks a function on to a specific action. |
| add_filter() | Attaches the specified PHP function to the specified filter hook. Thus, when the filter is triggered, the value will be filtered by the specified PHP function. |
| apply_filters() | Call the functions added to a filter hook. |
| apply_filters_ref_array() | Execute functions hooked on a specific filter hook, specifying arguments in an array. |
| current_filter() | Retrieve the name of the current filter or action. |
| did_action() | Retrieve the number of times an action (hook) is fired. |
| do_action() | Creates an event (a hook for a php function). For the function to work during the action, it should be added to this action with add_action(). |
| do_action_ref_array() | Creates an action (hook) on which PHP functions can then be attached. The arguments are passed as an array. |
| doing_action() | Retrieve the name of an action currently being processed. |
| doing_filter() | Retrieve the name of a filter currently being processed. |
| has_action() | Check if any action has been registered for a hook. |
| has_filter() | Check if any filter has been registered for a hook. |
| remove_action() | Removes a function from a specified action hook. |
| remove_all_actions() | Removes all of the callback functions from an action hook. |
| remove_all_filters() | Remove all of the hooks from a filter. |
| remove_filter() | Removes a function from a specified filter hook. |