add_theme_support() │ WP 2.9.0
Registers theme support for a given feature.
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.
Example usage:
add_theme_support( 'title-tag' );
add_theme_support( 'custom-logo', array(
'height' => 480,
'width' => 720,
) );
No Hooks.
Return
null|false
. Void on success, false on failure.
Usage
add_theme_support( $feature, ...$args );
$feature(string) (required)
The feature being added. Likely core values include:
'admin-bar'
'align-wide'
'automatic-feed-links'
'core-block-patterns'
'custom-background'
'custom-header'
'custom-line-height'
'custom-logo'
'customize-selective-refresh-widgets'
'custom-spacing'
'custom-units'
'dark-editor-style'
'disable-custom-colors'
'disable-custom-font-sizes'
'editor-color-palette'
'editor-gradient-presets'
'editor-font-sizes'
'editor-styles'
'featured-content'
'html5'
'menus'
'post-formats'
'post-thumbnails'
'responsive-embeds'
'starter-content'
'title-tag'
'wp-block-styles'
'widgets'
'widgets-block-editor'
...$args(mixed) (required)
Optional extra arguments to pass along with certain features.
Examples
#1 Example of registering theme features
This code should be inserted into the theme's functions.php file.
// Register theme features
add_action( 'after_setup_theme', function(){
// the ability to change the background from the admin panel
add_theme_support( 'custom-background' );
// the ability to change the images in the header from the admin panel
add_theme_support( 'custom-header' );
// enable the menu in the admin panel
add_theme_support( 'menus' );
// create a meta tag <title> via hook
add_theme_support( 'title-tag' );
// possibility to load a logo image in the admin panel
add_theme_support( 'custom-logo', [
'height' => 190,
'width' => 190,
'flex-width' => false,
'flex-height' => false,
'header-text' => '',
] );
}
Add Your Own Example
Notes
Global. Array. $_wp_theme_features
Changelog
Since 2.9.0
Introduced.
Since 3.4.0
The custom-header-uploads feature was deprecated.
Since 3.6.0
The html5 feature was added.
Since 3.6.1
The html5 feature requires an array of types to be passed. Defaults to 'comment-list' , 'comment-form' , 'search-form' for backward compatibility.
Since 3.9.0
The html5 feature now also accepts 'gallery' and 'caption' .
Since 4.1.0
The title-tag feature was added.
Since 4.5.0
The customize-selective-refresh-widgets feature was added.
Since 4.7.0
The starter-content feature was added.
Since 5.0.0
The responsive-embeds , align-wide , dark-editor-style , disable-custom-colors , disable-custom-font-sizes , editor-color-palette , editor-font-sizes , editor-styles , and wp-block-styles features were added.
Since 5.3.0
The html5 feature now also accepts 'script' and 'style' .
Since 5.3.0
Formalized the existing and already documented ...$args parameter by adding it to the function signature.
Since 5.5.0
The core-block-patterns feature was added and is enabled by default.
Since 5.5.0
The custom-logo feature now also accepts 'unlink-homepage-logo' .
Since 5.6.0
The post-formats feature warns if no array is passed as the second parameter.
Since 5.8.0
The widgets-block-editor feature enables the Widgets block editor.
Since 6.0.0
The html5 feature warns if no array is passed as the second parameter.
add_theme_support() add theme support code
WP 6.1.1
function add_theme_support( $feature, ...$args ) {
global $_wp_theme_features;
if ( ! $args ) {
$args = true;
}
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 ) );
} else {
_doing_it_wrong(
"add_theme_support( 'post-formats' )",
__( 'You need to pass an array of post formats.' ),
'5.6.0'
);
return false;
}
break;
case 'html5':
// You can't just pass 'html5', you need to pass an array of types.
if ( empty( $args[0] ) || ! is_array( $args[0] ) ) {
_doing_it_wrong(
"add_theme_support( 'html5' )",
__( 'You need to pass an array of types.' ),
'3.6.1'
);
if ( ! empty( $args[0] ) && ! is_array( $args[0] ) ) {
return false;
}
// Build an array of types for back-compat.
$args = array( 0 => array( 'comment-list', 'comment-form', 'search-form' ) );
}
// 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' => '',
'unlink-homepage-logo' => false,
);
$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', $args[0]['default-image'] );
}
break;
// Ensure that 'title-tag' is accessible in the admin.
case 'title-tag':
// Can be called in functions.php but must happen before wp_loaded, i.e. not in header.php.
if ( did_action( 'wp_loaded' ) ) {
_doing_it_wrong(
"add_theme_support( 'title-tag' )",
sprintf(
/* translators: 1: title-tag, 2: wp_loaded */
__( 'Theme support for %1$s should be registered before the %2$s hook.' ),
'<code>title-tag</code>',
'<code>wp_loaded</code>'
),
'4.1.0'
);
return false;
}
}
$_wp_theme_features[ $feature ] = $args;
}
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