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

Displays a human readable HTML representation of the difference between two strings.

Description

The Diff is available for getting the changes between versions. The output is HTML, so the primary use is for displaying the changes. If the two strings are equivalent, then an empty string will be returned.

See also

Parameters

$left_string

(string) (Required) "old" (left) version of string

$right_string

(string) (Required) "new" (right) version of string

$args

(string|array) (Optional) Associative array of options to pass to WP_Text_Diff_Renderer_Table().

  • 'title'
    (string) Titles the diff in a manner compatible with the output. Default empty.
  • 'title_left'
    (string) Change the HTML to the left of the title. Default empty.
  • 'title_right'
    (string) Change the HTML to the right of the title. Default empty.
  • 'show_split_view'
    (bool) True for split view (two columns), false for un-split view (single column). Default true.

Default value: null

Return

(string) Empty string if strings are equivalent or HTML with differences.

Source

File: wp-includes/pluggable.php

function wp_text_diff( $left_string, $right_string, $args = null ) {
		$defaults = array(
			'title'           => '',
			'title_left'      => '',
			'title_right'     => '',
			'show_split_view' => true,
		);
		$args     = wp_parse_args( $args, $defaults );

		if ( ! class_exists( 'WP_Text_Diff_Renderer_Table', false ) ) {
			require ABSPATH . WPINC . '/wp-diff.php';
		}

		$left_string  = normalize_whitespace( $left_string );
		$right_string = normalize_whitespace( $right_string );

		$left_lines  = explode( "\n", $left_string );
		$right_lines = explode( "\n", $right_string );
		$text_diff   = new Text_Diff( $left_lines, $right_lines );
		$renderer    = new WP_Text_Diff_Renderer_Table( $args );
		$diff        = $renderer->render( $text_diff );

		if ( ! $diff ) {
			return '';
		}

		$is_split_view       = ! empty( $args['show_split_view'] );
		$is_split_view_class = $is_split_view ? ' is-split-view' : '';

		$r = "<table class='diff$is_split_view_class'>\n";

		if ( $args['title'] ) {
			$r .= "<caption class='diff-title'>$args[title]</caption>\n";
		}

		if ( $args['title_left'] || $args['title_right'] ) {
			$r .= '<thead>';
		}

		if ( $args['title_left'] || $args['title_right'] ) {
			$th_or_td_left  = empty( $args['title_left'] ) ? 'td' : 'th';
			$th_or_td_right = empty( $args['title_right'] ) ? 'td' : 'th';

			$r .= "<tr class='diff-sub-title'>\n";
			$r .= "\t<$th_or_td_left>$args[title_left]</$th_or_td_left>\n";
			if ( $is_split_view ) {
				$r .= "\t<$th_or_td_right>$args[title_right]</$th_or_td_right>\n";
			}
			$r .= "</tr>\n";
		}

		if ( $args['title_left'] || $args['title_right'] ) {
			$r .= "</thead>\n";
		}

		$r .= "<tbody>\n$diff\n</tbody>\n";
		$r .= '</table>';

		return $r;
	}

Changelog

Version Description
2.6.0 Introduced.

© 2003–2021 WordPress Foundation
Licensed under the GNU GPLv2+ License.
https://developer.wordpress.org/reference/functions/wp_text_diff