_wp_get_iframed_editor_assets()
wp-includes/block-editor.php
|
Collect the block editor assets that need to be loaded into the editor’s iframe.
|
WP_REST_Menu_Items_Controller::prepare_item_for_response()
wp-includes/rest-api/endpoints/class-wp-rest-menu-items-controller.php
|
Prepares a single post output for response.
|
WP_REST_Global_Styles_Controller::prepare_item_for_response()
wp-includes/rest-api/endpoints/class-wp-rest-global-styles-controller.php
|
Prepare a global styles config output for response.
|
_add_default_theme_supports()
wp-includes/theme.php
|
Adds default theme supports for block themes when the ‘setup_theme’ action fires.
|
wp_enqueue_block_style()
wp-includes/script-loader.php
|
Enqueues a stylesheet for a specific block.
|
WP_Widget_Block::__construct()
wp-includes/widgets/class-wp-widget-block.php
|
Sets up a new Block widget instance.
|
wp_enqueue_global_styles()
wp-includes/script-loader.php
|
Enqueues the global styles defined via theme.json.
|
WP_Sitemaps_Renderer::check_for_simple_xml_availability()
wp-includes/sitemaps/class-wp-sitemaps-renderer.php
|
Checks for the availability of the SimpleXML extension and errors if missing.
|
WP_Sitemaps::init()
wp-includes/sitemaps/class-wp-sitemaps.php
|
Initiates all sitemap functionality.
|
wp_pre_kses_block_attributes()
wp-includes/formatting.php
|
Removes non-allowable HTML from parsed block attribute values when filtering in the post context.
|
enqueue_block_styles_assets()
wp-includes/script-loader.php
|
Function responsible for enqueuing the styles required for block styles functionality on the editor and on the frontend.
|
WP_Site_Health::__construct()
wp-admin/includes/class-wp-site-health.php
|
WP_Site_Health constructor.
|
wp_init_targeted_link_rel_filters()
wp-includes/formatting.php
|
Adds all filters modifying the rel attribute of targeted links.
|
wp_get_active_and_valid_themes()
wp-includes/load.php
|
Retrieves an array of active and valid themes.
|
update_sitemeta_cache()
wp-includes/ms-site.php
|
Updates metadata cache for list of site IDs.
|
WP_REST_Post_Search_Handler::prepare_item()
wp-includes/rest-api/search/class-wp-rest-post-search-handler.php
|
Prepares the search result for a given ID.
|
do_blocks()
wp-includes/blocks.php
|
Parses dynamic blocks out of post_content and re-renders them.
|
_restore_wpautop_hook()
wp-includes/blocks.php
|
If do_blocks() needs to remove wpautop() from the the_content filter, this re-adds it afterwards, for subsequent the_content usage.
|
wpdb::placeholder_escape()
wp-includes/class-wpdb.php
|
Generates and returns a placeholder escape string for use in queries returned by ::prepare().
|
WP_Widget_Custom_HTML::widget()
wp-includes/widgets/class-wp-widget-custom-html.php
|
Outputs the content for the current Custom HTML widget instance.
|
WP_Widget_Media::_register_one()
wp-includes/widgets/class-wp-widget-media.php
|
Add hooks while registering all widget instances of this widget class.
|
WP_Widget_Media_Video::render_media()
wp-includes/widgets/class-wp-widget-media-video.php
|
Render the media on the frontend.
|
WP_Customize_Manager::save_changeset_post()
wp-includes/class-wp-customize-manager.php
|
Saves the post for the loaded changeset.
|
WP_REST_Attachments_Controller::prepare_items_query()
wp-includes/rest-api/endpoints/class-wp-rest-attachments-controller.php
|
Determines the allowed query_vars for a get_items() response and prepares for WP_Query.
|
WP_REST_Posts_Controller::prepare_item_for_response()
wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php
|
Prepares a single post output for response.
|
WP_REST_Posts_Controller::get_item_permissions_check()
wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php
|
Checks if a given request has access to read a post.
|
WP_REST_Posts_Controller::get_items()
wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php
|
Retrieves a collection of posts.
|
WP_REST_Comments_Controller::check_read_post_permission()
wp-includes/rest-api/endpoints/class-wp-rest-comments-controller.php
|
Checks if the post can be read.
|
WP_Locale_Switcher::init()
wp-includes/class-wp-locale-switcher.php
|
Initializes the locale switcher.
|
WP_Taxonomy::add_hooks()
wp-includes/class-wp-taxonomy.php
|
Registers the ajax callback for the meta box.
|
WP_Customize_Nav_Menus::insert_auto_draft_post()
wp-includes/class-wp-customize-nav-menus.php
|
Adds a new auto-draft post.
|
WP_Customize_Custom_CSS_Setting::preview()
wp-includes/customize/class-wp-customize-custom-css-setting.php
|
Add filter to preview post value.
|
WP_Metadata_Lazyloader::queue_objects()
wp-includes/class-wp-metadata-lazyloader.php
|
Adds objects to the metadata lazy-load queue.
|
WP_Customize_Widgets::render_widget_partial()
wp-includes/class-wp-customize-widgets.php
|
Renders a specific widget using the supplied sidebar arguments.
|
WP_Customize_Widgets::selective_refresh_init()
wp-includes/class-wp-customize-widgets.php
|
Adds hooks for selective refresh.
|
rest_api_default_filters()
wp-includes/rest-api.php
|
Registers the default REST API filters.
|
wp_handle_comment_submission()
wp-includes/comment.php
|
Handles the submission of a comment, usually posted to wp-comments-post.php via a comment form.
|
WP_Screen::render_view_mode()
wp-admin/includes/class-wp-screen.php
|
Renders the list table view mode preferences.
|
WP_Customize_Nav_Menu_Setting::update()
wp-includes/customize/class-wp-customize-nav-menu-setting.php
|
Create/update the nav_menu term for this setting.
|
WP_Customize_Nav_Menu_Setting::preview()
wp-includes/customize/class-wp-customize-nav-menu-setting.php
|
Handle previewing the setting.
|
WP_Customize_Nav_Menu_Item_Setting::update()
wp-includes/customize/class-wp-customize-nav-menu-item-setting.php
|
Creates/updates the nav_menu_item post for this setting.
|
WP_Customize_Nav_Menu_Item_Setting::preview()
wp-includes/customize/class-wp-customize-nav-menu-item-setting.php
|
Handle previewing the setting.
|
WP_Customize_Nav_Menus_Panel::render_screen_options()
wp-includes/customize/class-wp-customize-nav-menus-panel.php
|
Render screen options for Menus.
|
WP_Customize_Nav_Menus::customize_preview_init()
wp-includes/class-wp-customize-nav-menus.php
|
Adds hooks for the Customizer preview.
|
WP_Customize_Nav_Menus::customize_register()
wp-includes/class-wp-customize-nav-menus.php
|
Adds the customizer settings and controls.
|
WP_Customize_Nav_Menus::__construct()
wp-includes/class-wp-customize-nav-menus.php
|
Constructor.
|
WP_Site_Icon::get_post_metadata()
wp-admin/includes/class-wp-site-icon.php
|
Adds custom image sizes when meta data for an image is requested, that happens to be used as Site Icon.
|
WP_Site_Icon::__construct()
wp-admin/includes/class-wp-site-icon.php
|
Registers actions and filters.
|
wp_ajax_crop_image()
wp-admin/includes/ajax-actions.php
|
Handles cropping an image via AJAX.
|
wp_edit_attachments_query_vars()
wp-admin/includes/post.php
|
Returns the query variables for the current attachments request.
|
_WP_List_Table_Compat::__construct()
wp-admin/includes/class-wp-list-table-compat.php
|
Constructor.
|
login_header()
wp-login.php
|
Outputs the login page header.
|
WP_Automatic_Updater::update()
wp-admin/includes/class-wp-automatic-updater.php
|
Updates an item, if appropriate.
|
Language_Pack_Upgrader::bulk_upgrade()
wp-admin/includes/class-language-pack-upgrader.php
|
Upgrades several language packs at once.
|
Plugin_Upgrader::bulk_upgrade()
wp-admin/includes/class-plugin-upgrader.php
|
Upgrades several plugins at once.
|
Theme_Upgrader::check_parent_theme_filter()
wp-admin/includes/class-theme-upgrader.php
|
Checks if a child theme is being installed and its parent also needs to be installed.
|
Theme_Upgrader::install()
wp-admin/includes/class-theme-upgrader.php
|
Install a theme package.
|
Theme_Upgrader::upgrade()
wp-admin/includes/class-theme-upgrader.php
|
Upgrades a theme.
|
Theme_Upgrader::bulk_upgrade()
wp-admin/includes/class-theme-upgrader.php
|
Upgrades several themes at once.
|
Plugin_Upgrader::install()
wp-admin/includes/class-plugin-upgrader.php
|
Install a plugin package.
|
Plugin_Upgrader::upgrade()
wp-admin/includes/class-plugin-upgrader.php
|
Upgrades a plugin.
|
WP_Screen::render_per_page_options()
wp-admin/includes/class-wp-screen.php
|
Renders the items per page option.
|
export_wp()
wp-admin/includes/export.php
|
Generates the WXR export file for download.
|
wp_update_core()
wp-admin/includes/deprecated.php
|
This was once used to kick-off the Core Updater.
|
wp_update_plugin()
wp-admin/includes/deprecated.php
|
This was once used to kick-off the Plugin Updater.
|
wp_update_theme()
wp-admin/includes/deprecated.php
|
This was once used to kick-off the Theme Updater.
|
WP_List_Table::__construct()
wp-admin/includes/class-wp-list-table.php
|
Constructor.
|
wp_dashboard_setup()
wp-admin/includes/dashboard.php
|
Registers dashboard widgets.
|
register_setting()
wp-includes/option.php
|
Registers a setting and its data.
|
media_upload_type_form()
wp-admin/includes/media.php
|
Outputs the legacy media upload form for a given media type.
|
media_upload_gallery_form()
wp-admin/includes/media.php
|
Adds gallery form to upload iframe.
|
media_upload_library_form()
wp-admin/includes/media.php
|
Outputs the legacy media upload form for the media library.
|
wp_ajax_query_attachments()
wp-admin/includes/ajax-actions.php
|
Handles querying attachments via AJAX.
|
wp_ajax_replyto_comment()
wp-admin/includes/ajax-actions.php
|
Handles replying to a comment via AJAX.
|
wp_link_manager_disabled_message()
wp-admin/includes/bookmark.php
|
Outputs the ‘disabled’ message for the WordPress Link Manager.
|
WP_Media_List_Table::display_rows()
wp-admin/includes/class-wp-media-list-table.php
|
|
WP_Importer::get_page()
wp-admin/includes/class-wp-importer.php
|
Gets URL.
|
WP_Comments_List_Table::__construct()
wp-admin/includes/class-wp-comments-list-table.php
|
Constructor.
|
wp_nav_menu_setup()
wp-admin/includes/nav-menu.php
|
Register nav menu meta boxes and advanced menu items.
|
wp_list_widget_controls()
wp-admin/includes/widgets.php
|
Show the widgets and their settings for a sidebar.
|
WP_Posts_List_Table::display_rows()
wp-admin/includes/class-wp-posts-list-table.php
|
|
do_core_upgrade()
wp-admin/update-core.php
|
Upgrades WordPress core display.
|
WP_Customize_Manager::customize_preview_init()
wp-includes/class-wp-customize-manager.php
|
Prints JavaScript settings.
|
WP_Customize_Manager::start_previewing_theme()
wp-includes/class-wp-customize-manager.php
|
If the theme to be previewed isn’t the active theme, add filter callbacks to swap it out at runtime.
|
WP_Customize_Manager::__construct()
wp-includes/class-wp-customize-manager.php
|
Constructor.
|
wp_trim_excerpt()
wp-includes/formatting.php
|
Generates an excerpt from the content, if needed.
|
kses_init_filters()
wp-includes/kses.php
|
Adds all KSES input form content filters.
|
_default_wp_die_handler()
wp-includes/functions.php
|
Kills WordPress execution and displays HTML page with an error message.
|
WP_Widget_Text::widget()
wp-includes/widgets/class-wp-widget-text.php
|
Outputs the content for the current Text widget instance.
|
WP_Widget_Text::form()
wp-includes/widgets/class-wp-widget-text.php
|
Outputs the Text widget settings form.
|
WP_Embed::__construct()
wp-includes/class-wp-embed.php
|
Constructor
|
do_shortcode()
wp-includes/shortcodes.php
|
Searches content for shortcodes and filter shortcodes through their hooks.
|
WP_oEmbed::__construct()
wp-includes/class-wp-oembed.php
|
Constructor.
|
add_action()
wp-includes/plugin.php
|
Adds a callback function to an action hook.
|
WP_Customize_Setting::__construct()
wp-includes/class-wp-customize-setting.php
|
Constructor.
|
WP_Customize_Setting::preview()
wp-includes/class-wp-customize-setting.php
|
Add filters to supply the setting’s value when accessed.
|
wp_signon()
wp-includes/user.php
|
Authenticates and logs a user in with ‘remember’ capability.
|
_set_preview()
wp-includes/revision.php
|
Sets up the post object for preview based on the post autosave.
|
_show_post_preview()
wp-includes/revision.php
|
Filters the latest content for preview from the post autosave.
|
ms_upload_constants()
wp-includes/ms-default-constants.php
|
Defines Multisite upload constants.
|
Walker_Comment::start_el()
wp-includes/class-walker-comment.php
|
Starts the element output.
|
WP_Customize_Widgets::start_capturing_option_updates()
wp-includes/class-wp-customize-widgets.php
|
Begins keeping track of changes to widget options, caching new values.
|
WP_Customize_Widgets::capture_filter_pre_update_option()
wp-includes/class-wp-customize-widgets.php
|
Pre-filters captured option values before updating.
|
WP_Customize_Widgets::__construct()
wp-includes/class-wp-customize-widgets.php
|
Initial loader.
|
WP_Customize_Widgets::override_sidebars_widgets_for_theme_switch()
wp-includes/class-wp-customize-widgets.php
|
Override sidebars_widgets for theme switch.
|
WP_Customize_Widgets::customize_register()
wp-includes/class-wp-customize-widgets.php
|
Registers Customizer settings and controls for all sidebars and widgets.
|
wp_update_comment()
wp-includes/comment.php
|
Updates an existing comment in the database.
|
check_comment_flood_db()
wp-includes/comment.php
|
Hooks WP’s native database-based comment-flood check.
|
register_meta()
wp-includes/meta.php
|
Registers a meta key.
|
_WP_Editors::editor()
wp-includes/class-wp-editor.php
|
Outputs the HTML for a single instance of the editor.
|
Example: Let’s add extra sections to TwentySeventeen Front page.
By default, TwentySeventeen theme has 4 sections for the front page. This example will make them 6
To pass a variable to the called function of the filter, you can use closures (since PHP 5.3+) when the argument is not available in the original coded apply_filters. For example:
Example: Let display custom length of post excerpt.
By default, WordPress display 57 character. you can set custom length using above code. this time except length will be 40. it is a nice and easiest use of add_filter.
Example: If you want to inject a CLASS/ID CSS in content. Let’s add extra CLASS/ID to post content.
In the special case you have to add a filter before WordPress starts, you can create and pre-populate the global
$wp_filter
array instead of using the not-yet availableadd_filter
(oradd_action
) function:WP_Hook::build_preinitialized_hooks
will automatically take care of the rest.Though to remove your filter, you can only use the remove_all_filters() function.
The Callback
$function_to_add
need not be defined until the Filter hook fires. This means that:add_filter
function does not check that$function_to_add
existsfunction
statement for$function_to_add
can be defined after theadd_filter
statement, even in a conditional (e.g. –if
block) where the$function_to_add
function does not actually exist until after theadd_filter
function executesPoint 3 needs to be considered during Testing or Quality Control
An undefined $function_to_add function detected when a Filter hook fires is reported as a Warning error:
Warning: call_user_func_array() expects parameter 1 to be a valid callback, function 'reg_public1' not found or invalid function name in /var/www/example.com/public_html/wp-includes/class-wp-hook.php on line 288
Example
The filter
img_caption_shortcode
is applied inmedia.php
using the following call:The target filter function will be called with three arguments:
” <= This is normally the value the filter will be modifying
$attr
$content
In order for the filter function to actually receive the full argument list, the call to
add_filter()
must be modified to specify there are 3 arguments on the parameter list.