_custom_background_cb()

Cost profile

Measured from the compiled opcodes, not from a stopwatch. Every number here is identical on any machine that runs the same PHP version, and every function in core is ranked by these figures.

Cost class

Trivial

Touches nothing outside its own arguments.

Scaling

Constant

No loop in the body: the same number of instructions runs whatever you pass in.

Instructions

21–133

Executed per call on PHP 8.4, depending on the branch taken. The body compiles to 140.

Plugin surface

None

Nothing here hands control to plugin code.

Called by

0

Nothing in core calls this; the cost is only what you spend yourself.

What it touches

• hookthird-party callbacksapply_filters()one call below _custom_background_cb()

Further down the call graph this can also reach option, cache, serialize, transient and query — those are the worst case, several calls deep and usually down an error path, not what a normal call pays.

What one call costs · 5 distinct outcomes

One number would be a lie: the work depends on which branch runs. These are every distinct cost _custom_background_cb() can have, taken from its control-flow graph on PHP 8.4.

Across PHP versions

Oldest PHP that compiles this body: 7.4. An instruction is not a fixed amount of time, so a version with the same count is not necessarily the same speed; what the count rules out is a difference in the work itself.

Uses · 9

• set_url_scheme()Sets the scheme for a URL.
• get_background_image()Retrieves background image for custom background.
• get_background_color()Retrieves value for custom background color.
• get_theme_support()Gets the theme support arguments passed when registering that support.
• is_customize_preview()Whether the site is being previewed in the Customizer.
• maybe_hash_hex_color()Ensures that any hex color is properly hashed.
• sanitize_url()Sanitizes a URL for database or redirect usage.
• get_theme_mod()Retrieves theme modification value for the active theme.
• WP_HTML_Tag_Processor::__construct()Constructor.

Source

View on Trac ↗View on GitHub ↗

1877function _custom_background_cb() {1878	// $background is the saved custom image, or the default image.1879	$background = set_url_scheme( get_background_image() );1880 1881	/*1882	 * $color is the saved custom color.1883	 * A default has to be specified in style.css. It will not be printed here.1884	 */1885	$color = get_background_color();1886 1887	if ( get_theme_support( 'custom-background', 'default-color' ) === $color ) {1888		$color = false;1889	}1890 1891	if ( ! $background && ! $color ) {1892		if ( is_customize_preview() ) {1893			echo '<style id="custom-background-css"></style>';1894		}1895		return;1896	}1897 1898	$style = $color ? 'background-color: ' . maybe_hash_hex_color( $color ) . ';' : '';1899 1900	if ( $background ) {1901		$image = ' background-image: url("' . sanitize_url( $background ) . '");';1902 1903		// Background Position.1904		$position_x = get_theme_mod( 'background_position_x', get_theme_support( 'custom-background', 'default-position-x' ) );1905		$position_y = get_theme_mod( 'background_position_y', get_theme_support( 'custom-background', 'default-position-y' ) );1906 1907		if ( ! in_array( $position_x, array( 'left', 'center', 'right' ), true ) ) {1908			$position_x = 'left';1909		}1910 1911		if ( ! in_array( $position_y, array( 'top', 'center', 'bottom' ), true ) ) {1912			$position_y = 'top';1913		}1914 1915		$position = " background-position: $position_x $position_y;";1916 1917		// Background Size.1918		$size = get_theme_mod( 'background_size', get_theme_support( 'custom-background', 'default-size' ) );1919 1920		if ( ! in_array( $size, array( 'auto', 'contain', 'cover' ), true ) ) {1921			$size = 'auto';1922		}1923 1924		$size = " background-size: $size;";1925 1926		// Background Repeat.1927		$repeat = get_theme_mod( 'background_repeat', get_theme_support( 'custom-background', 'default-repeat' ) );1928 1929		if ( ! in_array( $repeat, array( 'repeat-x', 'repeat-y', 'repeat', 'no-repeat' ), true ) ) {1930			$repeat = 'repeat';1931		}1932 1933		$repeat = " background-repeat: $repeat;";1934 1935		// Background Scroll.1936		$attachment = get_theme_mod( 'background_attachment', get_theme_support( 'custom-background', 'default-attachment' ) );1937 1938		if ( 'fixed' !== $attachment ) {1939			$attachment = 'scroll';1940		}1941 1942		$attachment = " background-attachment: $attachment;";1943 1944		$style .= $image . $position . $size . $repeat . $attachment;1945	}1946 1947	$processor = new WP_HTML_Tag_Processor( '<style id="custom-background-css"></style>' );1948	$processor->next_tag();1949 1950	$style_tag_content = 'body.custom-background { ' . trim( $style ) . ' }';1951	$processor->set_modifiable_text( "\n{$style_tag_content}\n" );1952	echo "{$processor->get_updated_html()}\n";1953}

History

Introduced in 3.0.0. Unchanged from 6.7.7 through 7.1.0.

1. 6.7.7
2. 6.8.8
3. 6.9.7
4. 7.0.4
5. 7.1.0

Signature, return type and hooks compared across 5 parsed releases.

About this page

Parsed data

Generated from the wordpress-develop 7.0.4 tag, from src/wp-includes/theme.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.

Corrections

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