wp_text_diff( string $left_string, string $right_string, string|array $args = null ): 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

$left_stringstring

"old" (left) version of string.

$right_stringstring

"new" (right) version of string.

$argsstring|arrayoptional

Associative array of options to pass to WP_Text_Diff_Renderer_Table().Default: null

• $titlestringdefault: empty

  Titles the diff in a manner compatible with the output.

• $title_leftstringdefault: empty

  Change the HTML to the left of the title.

• $title_rightstringdefault: empty

  Change the HTML to the right of the title.

• $show_split_viewbooldefault: true

  True for split view (two columns), false for un-split view (single column).

Return value

string

Empty string if strings are equivalent or HTML with differences.

Performance profile

How much work a call to wp_text_diff() 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

44–117

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 121.

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 one call costs · 1 distinct outcome

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

Uses · 4

• wp_parse_args()Merges user defined arguments into defaults array.
• normalize_whitespace()Normalizes EOL characters and strips duplicate whitespace.
• Text_Diff::__construct()Computes diffs between sequences of strings.
• WP_Text_Diff_Renderer_Table::__construct()Constructor - Call parent constructor with params array.

Used by · 1

• wp_get_revision_ui_diff()Get the revision UI diff.

Source code

View on Trac ↗View on GitHub ↗

3282	function wp_text_diff( $left_string, $right_string, $args = null ) {3283		$defaults = array(3284			'title'           => '',3285			'title_left'      => '',3286			'title_right'     => '',3287			'show_split_view' => true,3288		);3289		$args     = wp_parse_args( $args, $defaults );3290 3291		if ( ! class_exists( 'WP_Text_Diff_Renderer_Table', false ) ) {3292			require ABSPATH . WPINC . '/wp-diff.php';3293		}3294 3295		$left_string  = normalize_whitespace( $left_string );3296		$right_string = normalize_whitespace( $right_string );3297 3298		$left_lines  = explode( "\n", $left_string );3299		$right_lines = explode( "\n", $right_string );3300		$text_diff   = new Text_Diff( $left_lines, $right_lines );3301		$renderer    = new WP_Text_Diff_Renderer_Table( $args );3302		$diff        = $renderer->render( $text_diff );3303 3304		if ( ! $diff ) {3305			return '';3306		}3307 3308		$is_split_view       = ! empty( $args['show_split_view'] );3309		$is_split_view_class = $is_split_view ? ' is-split-view' : '';3310 3311		$r = "<table class='diff$is_split_view_class'>\n";3312 3313		if ( $args['title'] ) {3314			$r .= "<caption class='diff-title'>$args[title]</caption>\n";3315		}3316 3317		if ( $args['title_left'] || $args['title_right'] ) {3318			$r .= '<thead>';3319		}3320 3321		if ( $args['title_left'] || $args['title_right'] ) {3322			$th_or_td_left  = empty( $args['title_left'] ) ? 'td' : 'th';3323			$th_or_td_right = empty( $args['title_right'] ) ? 'td' : 'th';3324 3325			$r .= "<tr class='diff-sub-title'>\n";3326			$r .= "\t<$th_or_td_left>$args[title_left]</$th_or_td_left>\n";3327			if ( $is_split_view ) {3328				$r .= "\t<$th_or_td_right>$args[title_right]</$th_or_td_right>\n";3329			}3330			$r .= "</tr>\n";3331		}3332 3333		if ( $args['title_left'] || $args['title_right'] ) {3334			$r .= "</thead>\n";3335		}3336 3337		$r .= "<tbody>\n$diff\n</tbody>\n";3338		$r .= '</table>';3339 3340		return $r;3341	}

Changelog

Introduced in 2.6.0. 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/pluggable.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.

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