_custom_background_cb()
- Since
- 3.0.0
- Source
wp-includes/theme.php:1878
Compatibility
- WordPress
- since 3.0.0
- PHP
- 7.4–8.6-dev
- 6.7.7
- 6.8.8
- 6.9.7
- 7.0.4
- 7.1.0
Present in every tracked release (6.7.7 to 7.1.0), and compiles on PHP 7.4 through 8.6-dev.
Performance profile
How much work a call to _custom_background_cb() does, and what it touches: the algorithmic scaling, the Zend instruction count per call across PHP versions, the hooks it hands control to, and the core code that calls it. Measured from the compiled opcodes, not a stopwatch, so every number is identical on any machine running the same PHP version, and every function in core is ranked by cost.
- Cost class
- Trivial
- Scaling
- Constant
- Instructions
- 21–133
- Plugin surface
- None
- Called by
- 0
Touches nothing outside its own arguments.
No loop in the body: the same number of instructions runs whatever you pass in.
Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 140.
Nothing here hands control to plugin code.
Nothing in core calls this; the cost is only what you spend yourself.
What it touches
- hookthird-party callbacks
apply_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 8.5.
| When | Instructions | Calls it makes |
|---|---|---|
| always | 21–23 | get_background_image(), set_url_scheme(), get_background_color(), get_theme_support(), is_customize_preview() |
| always | 40–41 | get_background_image(), set_url_scheme(), get_background_color(), get_theme_support(), ->next_tag(), ->set_modifiable_text(), ->get_updated_html() |
| always | 45–46 | get_background_image(), set_url_scheme(), get_background_color(), get_theme_support(), maybe_hash_hex_color(), ->next_tag(), ->set_modifiable_text(), ->get_updated_html() |
| always | 122–128 | get_background_image(), set_url_scheme(), get_background_color(), get_theme_support(), sanitize_url(), get_theme_support(), get_theme_mod(), get_theme_support(), get_theme_mod(), get_theme_support(), get_theme_mod(), get_theme_support(), get_theme_mod(), get_theme_support(), get_theme_mod(), ->next_tag(), ->set_modifiable_text(), ->get_updated_html() |
| always | 127–133 | get_background_image(), set_url_scheme(), get_background_color(), get_theme_support(), maybe_hash_hex_color(), sanitize_url(), get_theme_support(), get_theme_mod(), get_theme_support(), get_theme_mod(), get_theme_support(), get_theme_mod(), get_theme_support(), get_theme_mod(), get_theme_support(), get_theme_mod(), ->next_tag(), ->set_modifiable_text(), ->get_updated_html() |
Across PHP versions
| PHP | Compiled | Executed | Branches | Notes |
|---|---|---|---|---|
| 8.6-dev | 140 | 21–133 | 11 | |
| 8.5 | 140 | 21–133 | 11 | |
| 8.4 | 140 | 21–133 | 11 | 2 fewer instructions than PHP 8.3 |
| 8.3 | 142 | 21–135 | 11 | |
| 8.2 | 142 | 21–135 | 11 | |
| 8.1 | 142 | 21–135 | 11 | 1 fewer instruction than PHP 7.4 |
| 7.4 | 143 | 21–136 | 11 |
An instruction is not a fixed amount of time, so a matching count is not necessarily the same speed; what it 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 code
function _custom_background_cb() { // $background is the saved custom image, or the default image. $background = set_url_scheme( get_background_image() ); /* * $color is the saved custom color. * A default has to be specified in style.css. It will not be printed here. */ $color = get_background_color(); if ( get_theme_support( 'custom-background', 'default-color' ) === $color ) { $color = false; } if ( ! $background && ! $color ) { if ( is_customize_preview() ) { echo '<style id="custom-background-css"></style>'; } return; } $style = $color ? 'background-color: ' . maybe_hash_hex_color( $color ) . ';' : ''; if ( $background ) { $image = ' background-image: url("' . sanitize_url( $background ) . '");'; // Background Position. $position_x = get_theme_mod( 'background_position_x', get_theme_support( 'custom-background', 'default-position-x' ) ); $position_y = get_theme_mod( 'background_position_y', get_theme_support( 'custom-background', 'default-position-y' ) ); if ( ! in_array( $position_x, array( 'left', 'center', 'right' ), true ) ) { $position_x = 'left'; } if ( ! in_array( $position_y, array( 'top', 'center', 'bottom' ), true ) ) { $position_y = 'top'; } $position = " background-position: $position_x $position_y;"; // Background Size. $size = get_theme_mod( 'background_size', get_theme_support( 'custom-background', 'default-size' ) ); if ( ! in_array( $size, array( 'auto', 'contain', 'cover' ), true ) ) { $size = 'auto'; } $size = " background-size: $size;"; // Background Repeat. $repeat = get_theme_mod( 'background_repeat', get_theme_support( 'custom-background', 'default-repeat' ) ); if ( ! in_array( $repeat, array( 'repeat-x', 'repeat-y', 'repeat', 'no-repeat' ), true ) ) { $repeat = 'repeat'; } $repeat = " background-repeat: $repeat;"; // Background Scroll. $attachment = get_theme_mod( 'background_attachment', get_theme_support( 'custom-background', 'default-attachment' ) ); if ( 'fixed' !== $attachment ) { $attachment = 'scroll'; } $attachment = " background-attachment: $attachment;"; $style .= $image . $position . $size . $repeat . $attachment; } $processor = new WP_HTML_Tag_Processor( '<style id="custom-background-css"></style>' ); $processor->next_tag(); $style_tag_content = 'body.custom-background { ' . trim( $style ) . ' }'; $processor->set_modifiable_text( "\n{$style_tag_content}\n" ); echo "{$processor->get_updated_html()}\n";}Changelog
Introduced in 3.0.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
About this page
- Parsed data
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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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