add_theme_support( string $feature )
Registers theme support for a given feature.
Description
Must be called in the theme’s functions.php file to work. If attached to a hook, it must be ‘after_setup_theme’. The ‘init’ hook may be too late for some features.
Parameters
- $feature
-
(Required) The feature being added. Likely core values include 'post-formats', 'post-thumbnails', 'html5', 'custom-logo', 'custom-header-uploads', 'custom-header', 'custom-background', 'title-tag', 'starter-content', etc.
- $args,...
-
(Optional) extra arguments to pass along with certain features.
Return
(void|bool) False on failure, void otherwise.
Source
File: wp-includes/theme.php
function add_theme_support( $feature ) {
global $_wp_theme_features;
if ( func_num_args() == 1 )
$args = true;
else
$args = array_slice( func_get_args(), 1 );
switch ( $feature ) {
case 'post-thumbnails':
// All post types are already supported.
if ( true === get_theme_support( 'post-thumbnails' ) ) {
return;
}
/*
* Merge post types with any that already declared their support
* for post thumbnails.
*/
if ( isset( $args[0] ) && is_array( $args[0] ) && isset( $_wp_theme_features['post-thumbnails'] ) ) {
$args[0] = array_unique( array_merge( $_wp_theme_features['post-thumbnails'][0], $args[0] ) );
}
break;
case 'post-formats':
if ( isset( $args[0] ) && is_array( $args[0] ) ) {
$post_formats = get_post_format_slugs();
unset( $post_formats['standard'] );
$args[0] = array_intersect( $args[0], array_keys( $post_formats ) );
}
break;
case 'html5' :
// You can't just pass 'html5', you need to pass an array of types.
if ( empty( $args[0] ) ) {
// Build an array of types for back-compat.
$args = array( 0 => array( 'comment-list', 'comment-form', 'search-form' ) );
} elseif ( ! isset( $args[0] ) || ! is_array( $args[0] ) ) {
_doing_it_wrong( "add_theme_support( 'html5' )", __( 'You need to pass an array of types.' ), 'WP-3.6.1' );
return false;
}
// Calling 'html5' again merges, rather than overwrites.
if ( isset( $_wp_theme_features['html5'] ) )
$args[0] = array_merge( $_wp_theme_features['html5'][0], $args[0] );
break;
case 'custom-logo':
if ( true === $args ) {
$args = array( 0 => array() );
}
$defaults = array(
'width' => null,
'height' => null,
'flex-width' => false,
'flex-height' => false,
'header-text' => '',
);
$args[0] = wp_parse_args( array_intersect_key( $args[0], $defaults ), $defaults );
// Allow full flexibility if no size is specified.
if ( is_null( $args[0]['width'] ) && is_null( $args[0]['height'] ) ) {
$args[0]['flex-width'] = true;
$args[0]['flex-height'] = true;
}
break;
case 'custom-header-uploads' :
return add_theme_support( 'custom-header', array( 'uploads' => true ) );
case 'custom-header':
if ( true === $args ) {
$args = array( 0 => array() );
}
$defaults = array(
'default-image' => '',
'random-default' => false,
'width' => 0,
'height' => 0,
'flex-height' => false,
'flex-width' => false,
'default-text-color' => '',
'header-text' => true,
'uploads' => true,
'wp-head-callback' => '',
'admin-head-callback' => '',
'admin-preview-callback' => '',
'video' => false,
'video-active-callback' => 'is_front_page',
);
$jit = isset( $args[0]['__jit'] );
unset( $args[0]['__jit'] );
// Merge in data from previous add_theme_support() calls.
// The first value registered wins. (A child theme is set up first.)
if ( isset( $_wp_theme_features['custom-header'] ) )
$args[0] = wp_parse_args( $_wp_theme_features['custom-header'][0], $args[0] );
// Load in the defaults at the end, as we need to insure first one wins.
// This will cause all constants to be defined, as each arg will then be set to the default.
if ( $jit )
$args[0] = wp_parse_args( $args[0], $defaults );
// If a constant was defined, use that value. Otherwise, define the constant to ensure
// the constant is always accurate (and is not defined later, overriding our value).
// As stated above, the first value wins.
// Once we get to wp_loaded (just-in-time), define any constants we haven't already.
// Constants are lame. Don't reference them. This is just for backward compatibility.
if ( defined( 'NO_HEADER_TEXT' ) )
$args[0]['header-text'] = ! NO_HEADER_TEXT;
elseif ( isset( $args[0]['header-text'] ) )
define( 'NO_HEADER_TEXT', empty( $args[0]['header-text'] ) );
if ( defined( 'HEADER_IMAGE_WIDTH' ) )
$args[0]['width'] = (int) HEADER_IMAGE_WIDTH;
elseif ( isset( $args[0]['width'] ) )
define( 'HEADER_IMAGE_WIDTH', (int) $args[0]['width'] );
if ( defined( 'HEADER_IMAGE_HEIGHT' ) )
$args[0]['height'] = (int) HEADER_IMAGE_HEIGHT;
elseif ( isset( $args[0]['height'] ) )
define( 'HEADER_IMAGE_HEIGHT', (int) $args[0]['height'] );
if ( defined( 'HEADER_TEXTCOLOR' ) )
$args[0]['default-text-color'] = HEADER_TEXTCOLOR;
elseif ( isset( $args[0]['default-text-color'] ) )
define( 'HEADER_TEXTCOLOR', $args[0]['default-text-color'] );
if ( defined( 'HEADER_IMAGE' ) )
$args[0]['default-image'] = HEADER_IMAGE;
elseif ( isset( $args[0]['default-image'] ) )
define( 'HEADER_IMAGE', $args[0]['default-image'] );
if ( $jit && ! empty( $args[0]['default-image'] ) )
$args[0]['random-default'] = false;
// If headers are supported, and we still don't have a defined width or height,
// we have implicit flex sizes.
if ( $jit ) {
if ( empty( $args[0]['width'] ) && empty( $args[0]['flex-width'] ) )
$args[0]['flex-width'] = true;
if ( empty( $args[0]['height'] ) && empty( $args[0]['flex-height'] ) )
$args[0]['flex-height'] = true;
}
break;
case 'custom-background':
if ( true === $args ) {
$args = array( 0 => array() );
}
$defaults = array(
'default-image' => '',
'default-preset' => 'default',
'default-position-x' => 'left',
'default-position-y' => 'top',
'default-size' => 'auto',
'default-repeat' => 'repeat',
'default-attachment' => 'scroll',
'default-color' => '',
'wp-head-callback' => '_custom_background_cb',
'admin-head-callback' => '',
'admin-preview-callback' => '',
);
$jit = isset( $args[0]['__jit'] );
unset( $args[0]['__jit'] );
// Merge in data from previous add_theme_support() calls. The first value registered wins.
if ( isset( $_wp_theme_features['custom-background'] ) )
$args[0] = wp_parse_args( $_wp_theme_features['custom-background'][0], $args[0] );
if ( $jit )
$args[0] = wp_parse_args( $args[0], $defaults );
if ( defined( 'BACKGROUND_COLOR' ) )
$args[0]['default-color'] = BACKGROUND_COLOR;
elseif ( isset( $args[0]['default-color'] ) || $jit )
define( 'BACKGROUND_COLOR', $args[0]['default-color'] );
if ( defined( 'BACKGROUND_IMAGE' ) )
$args[0]['default-image'] = BACKGROUND_IMAGE;
elseif ( isset( $args[0]['default-image'] ) || $jit )
define( 'BACKGROUND_IMAGE', $args[0]['default-image'] );
break;
// Ensure that 'title-tag' is accessible in the admin.
case 'title-tag' :
// Can be called in functions.php but must happen before wp_loaded, i.e. not in header.php.
if ( did_action( 'wp_loaded' ) ) {
/* translators: 1: Theme support 2: hook name */
_doing_it_wrong( "add_theme_support( 'title-tag' )", sprintf( __( 'Theme support for %1$s should be registered before the %2$s hook.' ),
'<code>title-tag</code>', '<code>wp_loaded</code>' ), 'WP-4.1.0' );
return false;
}
}
$_wp_theme_features[ $feature ] = $args;
}
Changelog
Version | Description |
---|---|
WP-4.7.0 | The starter-content feature was added |
WP-4.5.0 | The customize-selective-refresh-widgets feature was added |
WP-4.1.0 | The title-tag feature was added |
WP-3.9.0 | The html5 feature now also accepts 'gallery' and 'caption' |
WP-3.6.0 | The html5 feature was added |
WP-2.9.0 | Introduced. |