add_theme_support( string $feature )

Registers theme support for a given feature.


Description 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 Parameters

$feature

(string) (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', etc.

$args,...

(mixed) (Optional) extra arguments to pass along with certain features.


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Return Return

(void|bool) False on failure, void otherwise.


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Source 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 ( 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 ( 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 ( ! is_array( $args[0] ) ) {
				_doing_it_wrong( "add_theme_support( 'html5' )", __( 'You need to pass an array of types.' ), '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 ( ! is_array( $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 ( ! is_array( $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' => '',
			);

			$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 ( ! is_array( $args ) )
				$args = array( 0 => array() );

			$defaults = array(
				'default-image'          => '',
				'default-repeat'         => 'repeat',
				'default-position-x'     => 'left',
				'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>' ), '4.1.0' );

				return false;
			}
	}

	$_wp_theme_features[ $feature ] = $args;
}


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Changelog Changelog

Changelog
Version Description
4.5.0 The customize-selective-refresh-widgets feature was added
4.1.0 The title-tag feature was added
3.9.0 The html5 feature now also accepts 'gallery' and 'caption'
3.6.0 The html5 feature was added
2.9.0 Introduced.

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More Information More Information

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Features Features

Post Formats Post Formats

This feature enables Post Formats support for a theme. When using child themes, be aware that

add_theme_support( 'post-formats' )

will override the formats as defined by the parent theme, not add to it.

To enable the specific formats (see supported formats at Post Formats), use:

add_theme_support( 'post-formats', array( 'aside', 'gallery' ) );

To check if there is a ‘quote’ post format assigned to the post, use has_post_format():

// In your theme single.php, page.php or custom post type
if ( has_post_format( 'quote' ) ) {
	echo 'This is a quote.';
}

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Post Thumbnails Post Thumbnails

This feature enables Post Thumbnails support for a theme. Note that you can optionally pass a second argument, $args, with an array of the Post Types for which you want to enable this feature.

add_theme_support( 'post-thumbnails' );
add_theme_support( 'post-thumbnails', array( 'post' ) );          // Posts only
add_theme_support( 'post-thumbnails', array( 'page' ) );          // Pages only
add_theme_support( 'post-thumbnails', array( 'post', 'movie' ) ); // Posts and Movies

This feature must be called before the ‘init’ hook is fired. That means it needs to be placed directly into functions.php or within a function attached to the ‘after_setup_theme’ hook. For custom post types, you can also add post thumbnails using the register_post_type() function as well.

To display thumbnails in themes index.php or single.php or custom templates, use:

the_post_thumbnail();

To check if there is a post thumbnail assigned to the post before displaying it, use:

if ( has_post_thumbnail() ) {
	the_post_thumbnail();
}

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Custom Background Custom Background

This feature enables Custom_Backgrounds support for a theme.

add_theme_support( 'custom-background' );

Note that you can add default arguments using:

$defaults = array(
	'default-color'          => '',
	'default-image'          => '',
	'wp-head-callback'       => '_custom_background_cb',
	'admin-head-callback'    => '',
	'admin-preview-callback' => ''
);
add_theme_support( 'custom-background', $defaults );

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Custom Header Custom Header

This feature enables Custom_Headers support for a theme.

add_theme_support( 'custom-header' );

Note that you can add default arguments using:

$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' => '',
);
add_theme_support( 'custom-header', $defaults );

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This feature, first introduced in Version_4.5, enables Theme_Logo support for a theme.

add_theme_support( 'custom-logo' );

Note that you can add default arguments using:

add_theme_support( 'custom-logo', array(
	'height'      => 100,
	'width'       => 400,
	'flex-height' => true,
	'flex-width'  => true,
	'header-text' => array( 'site-title', 'site-description' ),
) );

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This feature enables Automatic Feed Links for post and comment in the head. This should be used in place of the deprecated automatic_feed_links() function.

add_theme_support( 'automatic-feed-links' );

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HTML5 HTML5

This feature allows the use of HTML5 markup for the search forms, comment forms, comment lists, gallery, and caption.

add_theme_support( 'html5', array( 'comment-list', 'comment-form', 'search-form', 'gallery', 'caption' ) );

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Title Tag Title Tag

This feature enables plugins and themes to manage the document title tag. This should be used in place of wp_title() function.

add_theme_support( 'title-tag' );

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Customize Selective Refresh Widgets Customize Selective Refresh Widgets

This feature enables Selective Refresh for Widgets being managed within the Customizer. This feature became available in WordPress 4.5. For more on why and how Selective Refresh works read Implementing Selective Refresh Support for Widgets.

add_theme_support( 'customize-selective-refresh-widgets' );

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Multisite Multisite

To show the “Featured Image” meta box in Multisite installation, make sure you update the allowed upload file types, in Network Admin, Network Admin Settings SubPanel#Upload_Settings, Media upload buttons options. Default is jpg jpeg png gif mp3 mov avi wmv midi mid pdf.

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Other Notes Other Notes

The following parameters are read only, and should only be used in the context of current_theme_supports():



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User Contributed Notes User Contributed Notes

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