wp_set_up_cross_origin_isolation()

Description

Compatibility

Present in 1 of the 5 tracked releases, added in 7.1.0, and compiles on PHP 7.4 through 8.6-dev.

Performance profile

How much work a call to wp_set_up_cross_origin_isolation() 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

Touches nothing outside its own arguments.

Scaling

Constant

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

Instructions

4–46

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 52.

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 wp_set_up_cross_origin_isolation()

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 · 14 distinct outcomes

One number would be a lie: the work depends on which branch runs. These are every distinct cost wp_set_up_cross_origin_isolation() can have, taken from its control-flow graph on PHP 8.5.

Uses · 6

• wp_is_client_side_media_processing_enabled()Checks whether client-side media processing is enabled.
• get_current_screen()Get the current screen object
• wp_use_widgets_block_editor()Determines whether or not to use the block editor to manage widgets.
• wp_is_block_theme()Returns whether the active theme is a block-based theme or not.
• current_user_can()Returns whether the current user has the specified capability.
• wp_start_cross_origin_isolation_output_buffer()Sends the Document-Isolation-Policy header for cross-origin isolation.

Source code

View on Trac ↗View on GitHub ↗

6646function wp_set_up_cross_origin_isolation(): void {6647	if ( ! wp_is_client_side_media_processing_enabled() ) {6648		return;6649	}6650 6651	$screen = get_current_screen();6652 6653	if ( ! $screen ) {6654		return;6655	}6656 6657	if ( ! $screen->is_block_editor() && 'site-editor' !== $screen->id && ! ( 'widgets' === $screen->id && wp_use_widgets_block_editor() ) ) {6658		return;6659	}6660 6661	/*6662	 * Skip when rendering the classic-theme home route, which shows the site6663	 * preview in an iframe and must reach its `contentDocument` to neutralize6664	 * interactive elements. DIP would block that same-origin access.6665	 *6666	 * Keyed off $pagenow rather than the current screen so the guard keeps6667	 * working if the header set-up is ever moved to an earlier hook (such as6668	 * admin_init) where the screen is not yet available.6669	 */6670	global $pagenow;6671 6672	// phpcs:ignore WordPress.Security.NonceVerification.Recommended6673	if ( 'site-editor.php' === $pagenow && ! wp_is_block_theme() && ( ! isset( $_GET['p'] ) || '/' === $_GET['p'] ) ) {6674		return;6675	}6676 6677	/*6678	 * Skip when a third-party page builder overrides the block editor.6679	 * DIP isolates the document into its own agent cluster,6680	 * which blocks same-origin iframe access that these editors rely on.6681	 */6682	if ( isset( $_GET['action'] ) && 'edit' !== $_GET['action'] ) {6683		return;6684	}6685 6686	// Cross-origin isolation is not needed if users can't upload files anyway.6687	if ( ! current_user_can( 'upload_files' ) ) {6688		return;6689	}6690 6691	wp_start_cross_origin_isolation_output_buffer();6692}

Changelog

Introduced in 7.1.0.

Signature, return type and hooks compared across 1 parsed release.

About this page

Parsed data

Generated from the wordpress-develop 7.1.0 tag, from src/wp-includes/media.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.

Corrections

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