parent_dropdown( int $default_page = 0, int $parent_page = 0, int $level = 0, int|WP_Post $post = null ): void|false

Compatibility

Present in every tracked release (6.7.7 to 7.1.0), and compiles on PHP 7.4 through 8.6-dev.

Parameters

$default_pageintoptional

The default page ID to be pre-selected. Default 0.Default: 0

$parent_pageintoptional

The parent page ID. Default 0.Default: 0

$levelintoptional

Page depth level. Default 0.Default: 0

$postint|WP_Postoptional

Post ID or WP_Post object.Default: null

Return value

void|false

Void on success, false if the page has no children.

Performance profile

How much work a call to parent_dropdown() 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

Heavy

Reaches the database via ->get_results().

Scaling

Scales with input

The body loops, so the work grows with what you pass in.

Instructions

23–26

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 76.

Plugin surface

None

Nothing here hands control to plugin code.

Called by

1

1 place in core call this, so the cost is paid more often than your own code shows.

What it touches

• querycontent queryget_post()called directly
• sqldatabase query->get_results()called directly
• hookthird-party callbacksapply_filters()one call below parent_dropdown()

Further down the call graph this can also reach option, 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 · 1 distinct outcome

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

Uses · 4

• get_post()Retrieves post data given a post ID or post object.
• selected()Outputs the HTML selected attribute.
• esc_html()Escaping for HTML blocks.
• parent_dropdown()Prints out option HTML elements for the page parents drop-down.

Used by · 1

• parent_dropdown()Prints out option HTML elements for the page parents drop-down.

Source code

View on Trac ↗View on GitHub ↗

934function parent_dropdown( $default_page = 0, $parent_page = 0, $level = 0, $post = null ) {935	global $wpdb;936 937	$post  = get_post( $post );938	$items = $wpdb->get_results(939		$wpdb->prepare(940			"SELECT ID, post_parent, post_title941			FROM $wpdb->posts942			WHERE post_parent = %d AND post_type = 'page'943			ORDER BY menu_order",944			$parent_page945		)946	);947 948	if ( $items ) {949		foreach ( $items as $item ) {950			// A page cannot be its own parent.951			if ( $post && $post->ID && (int) $item->ID === $post->ID ) {952				continue;953			}954 955			$pad      = str_repeat( '&nbsp;', $level * 3 );956			$selected = selected( $default_page, $item->ID, false );957 958			echo "\n\t<option class='level-$level' value='$item->ID' $selected>$pad " . esc_html( $item->post_title ) . '</option>';959			parent_dropdown( $default_page, $item->ID, $level + 1 );960		}961	} else {962		return false;963	}964}

Changelog

Introduced in 1.5.0. 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

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