handle_legacy_widget_preview_iframe()
- Since
- 5.8.0
- Source
wp-includes/blocks/legacy-widget.php:82
Compatibility
- WordPress
- since 5.8.0
- 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 handle_legacy_widget_preview_iframe() 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
- 4–43
- 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 45.
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
do_action()one call below handle_legacy_widget_preview_iframe()
Further down the call graph this can also reach option, query, cache, serialize and transient. Those are the worst case, several calls deep and usually down an error path, not what a normal call pays.
What one call costs · 3 distinct outcomes
One number would be a lie: the work depends on which branch runs. These are every distinct cost handle_legacy_widget_preview_iframe() can have, taken from its control-flow graph on PHP 8.5.
| When | Instructions | Calls it makes |
|---|---|---|
empty($value) | 4 | none |
!empty($value) && !current_user_can() | 8 | current_user_can() |
!empty($value) && current_user_can() | 43 | current_user_can(), language_attributes(), bloginfo(), wp_head(), body_class(), ::WP_Block_Type_Registry(), ->get_registered(), ->render(), wp_footer(), exit() |
Across PHP versions
| PHP | Compiled | Executed | Branches | Notes |
|---|---|---|---|---|
| 8.6-dev | 45 | 4–43 | 2 | |
| 8.5 | 45 | 4–43 | 2 | |
| 8.4 | 45 | 4–43 | 2 | 2 more instructions than PHP 8.3 |
| 8.3 | 43 | 4–41 | 2 | |
| 8.2 | 43 | 4–41 | 2 | |
| 8.1 | 43 | 4–41 | 2 | |
| 7.4 | 43 | 4–41 | 2 |
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 · 7
- current_user_can()Returns whether the current user has the specified capability.
- language_attributes()Displays the language attributes for the 'html' tag.
- bloginfo()Displays information about the current site.
- wp_head()Fires the wp_head action.
- body_class()Displays the class names for the body element.
- wp_footer()Fires the wp_footer action.
- WP_Block_Type_Registry::get_instance()Utility method to retrieve the main instance of the class.
Source code
function handle_legacy_widget_preview_iframe() { if ( empty( $_GET['legacy-widget-preview'] ) ) { return; } if ( ! current_user_can( 'edit_theme_options' ) ) { return; } define( 'IFRAME_REQUEST', true ); ?> <!doctype html> <html <?php language_attributes(); ?>> <head> <meta charset="<?php bloginfo( 'charset' ); ?>" /> <meta name="viewport" content="width=device-width, initial-scale=1" /> <link rel="profile" href="https://gmpg.org/xfn/11" /> <?php wp_head(); ?> <style> /* Reset theme styles */ html, body, #page, #content { padding: 0 !important; margin: 0 !important; } /* Hide root level text nodes */ body { font-size: 0 !important; } /* Hide non-widget elements */ body *:not(#page):not(#content):not(.widget):not(.widget *) { display: none !important; font-size: 0 !important; height: 0 !important; left: -9999px !important; max-height: 0 !important; max-width: 0 !important; opacity: 0 !important; pointer-events: none !important; position: absolute !important; top: -9999px !important; transform: translate(-9999px, -9999px) !important; visibility: hidden !important; z-index: -999 !important; } /* Restore widget font-size */ .widget { font-size: var(--global--font-size-base); } </style> </head> <body <?php body_class(); ?>> <div id="page" class="site"> <div id="content" class="site-content"> <?php $registry = WP_Block_Type_Registry::get_instance(); $block = $registry->get_registered( 'core/legacy-widget' ); echo $block->render( $_GET['legacy-widget-preview'] ); ?> </div><!-- #content --> </div><!-- #page --> <?php wp_footer(); ?> </body> </html> <?php exit;}Changelog
Introduced in 5.8.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
About this page
- Parsed data
- Generated from the wordpress-develop 7.1.0 tag, from
src/wp-includes/blocks/legacy-widget.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it. - Corrections
- Something wrong on this page? Report it and it gets fixed in the next regeneration.