Walker::paged_walk( array $elements, int $max_depth, int $page_num, int $per_page, mixed $args ): string

Description

Compatibility

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

Parameters

$elementsarray

An array of elements.

$max_depthint

The maximum hierarchical depth.

$page_numint

The specific page number, beginning with 1.

$per_pageint

Number of elements per page.

$argsmixed

Optional additional arguments.

Return value

string

XHTML of the specified page of elements.

Performance profile

How much work a call to Walker::paged_walk() 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

Light

Touches nothing outside its own arguments.

Scaling

Scales with input

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

Instructions

11–95

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 174.

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 one call costs · 12 distinct outcomes

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

This body has more branch combinations than are worth enumerating, so the table covers the outcomes found first rather than every one that exists.

Uses · 2

• Walker::display_element()Traverses elements to create list from elements.
• Walker::unset_children()Unsets all the children for a given top level element.

Source code

View on Trac ↗View on GitHub ↗

292	public function paged_walk( $elements, $max_depth, $page_num, $per_page, ...$args ) {293		$output = '';294 295		$max_depth = (int) $max_depth;296 297		if ( empty( $elements ) || $max_depth < -1 ) {298			return $output;299		}300 301		$parent_field = $this->db_fields['parent'];302 303		$count = -1;304		if ( -1 === $max_depth ) {305			$total_top = count( $elements );306		}307		if ( $page_num < 1 || $per_page < 0 ) {308			// No paging.309			$paging = false;310			$start  = 0;311			if ( -1 === $max_depth ) {312				$end = $total_top;313			}314			$this->max_pages = 1;315		} else {316			$paging = true;317			$start  = ( (int) $page_num - 1 ) * (int) $per_page;318			$end    = $start + $per_page;319			if ( -1 === $max_depth ) {320				$this->max_pages = (int) ceil( $total_top / $per_page );321			}322		}323 324		// Flat display.325		if ( -1 === $max_depth ) {326			if ( ! empty( $args[0]['reverse_top_level'] ) ) {327				$elements = array_reverse( $elements );328				$oldstart = $start;329				$start    = $total_top - $end;330				$end      = $total_top - $oldstart;331			}332 333			$empty_array = array();334			foreach ( $elements as $e ) {335				++$count;336				if ( $count < $start ) {337					continue;338				}339				if ( $count >= $end ) {340					break;341				}342				$this->display_element( $e, $empty_array, 1, 0, $args, $output );343			}344			return $output;345		}346 347		/*348		 * Separate elements into two buckets: top level and children elements.349		 * Children_elements is two dimensional array, e.g.350		 * $children_elements[10][] contains all sub-elements whose parent is 10.351		 */352		$top_level_elements = array();353		$children_elements  = array();354		foreach ( $elements as $e ) {355			if ( empty( $e->$parent_field ) ) {356				$top_level_elements[] = $e;357			} else {358				$children_elements[ $e->$parent_field ][] = $e;359			}360		}361 362		$total_top = count( $top_level_elements );363		if ( $paging ) {364			$this->max_pages = (int) ceil( $total_top / $per_page );365		} else {366			$end = $total_top;367		}368 369		if ( ! empty( $args[0]['reverse_top_level'] ) ) {370			$top_level_elements = array_reverse( $top_level_elements );371			$oldstart           = $start;

Changelog

Introduced in 2.7.0. 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 6.8.8 tag, from src/wp-includes/class-wp-walker.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.

Corrections

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