: str_replace(): Passing null to parameter #2 ($replace) of type array|string is deprecated in
* Diff API: WP_Text_Diff_Renderer_Table class
* Table renderer to display the diff lines.
* @uses Text_Diff_Renderer Extends
#[AllowDynamicProperties]
class WP_Text_Diff_Renderer_Table extends Text_Diff_Renderer {
* @see Text_Diff_Renderer::_leading_context_lines
public $_leading_context_lines = 10000;
* @see Text_Diff_Renderer::_trailing_context_lines
public $_trailing_context_lines = 10000;
* Title of the item being compared.
* @since 6.4.0 Declared a previously dynamic property.
* Title for the left column.
* @since 6.4.0 Declared a previously dynamic property.
* Title for the right column.
* @since 6.4.0 Declared a previously dynamic property.
* Threshold for when a diff should be saved or omitted.
protected $_diff_threshold = 0.6;
* Inline display helper object name.
protected $inline_diff_renderer = 'WP_Text_Diff_Renderer_inline';
* Should we show the split view or not
protected $_show_split_view = true;
protected $compat_fields = array( '_show_split_view', 'inline_diff_renderer', '_diff_threshold' );
* Caches the output of count_chars() in compute_string_distance()
protected $count_cache = array();
* Caches the difference calculation in compute_string_distance()
protected $difference_cache = array();
* Constructor - Call parent constructor with params array.
* This will set class properties based on the key value pairs in the array.
public function __construct( $params = array() ) {
parent::__construct( $params );
if ( isset( $params['show_split_view'] ) ) {
$this->_show_split_view = $params['show_split_view'];
public function _startBlock( $header ) {
public function _lines( $lines, $prefix = ' ' ) {
* @param string $line HTML-escape the value.
public function addedLine( $line ) {
return "<td class='diff-addedline'><span aria-hidden='true' class='dashicons dashicons-plus'></span><span class='screen-reader-text'>" .
/* translators: Hidden accessibility text. */
* @param string $line HTML-escape the value.
public function deletedLine( $line ) {
return "<td class='diff-deletedline'><span aria-hidden='true' class='dashicons dashicons-minus'></span><span class='screen-reader-text'>" .
/* translators: Hidden accessibility text. */
* @param string $line HTML-escape the value.
public function contextLine( $line ) {
return "<td class='diff-context'><span class='screen-reader-text'>" .
/* translators: Hidden accessibility text. */
public function emptyLine() {
return '<td> </td>';
public function _added( $lines, $encode = true ) {
foreach ( $lines as $line ) {
$processed_line = htmlspecialchars( $line );
* Contextually filters a diffed line.
* Filters TextDiff processing of diffed line. By default, diffs are processed with
* htmlspecialchars. Use this filter to remove or change the processing. Passes a context
* indicating if the line is added, deleted or unchanged.
* @param string $processed_line The processed diffed line.
* @param string $line The unprocessed diffed line.
* @param string $context The line context. Values are 'added', 'deleted' or 'unchanged'.
$line = apply_filters( 'process_text_diff_html', $processed_line, $line, 'added' );
if ( $this->_show_split_view ) {
$r .= '<tr>' . $this->emptyLine() . $this->addedLine( $line ) . "</tr>\n";
$r .= '<tr>' . $this->addedLine( $line ) . "</tr>\n";
public function _deleted( $lines, $encode = true ) {
foreach ( $lines as $line ) {
$processed_line = htmlspecialchars( $line );
/** This filter is documented in wp-includes/wp-diff.php */
$line = apply_filters( 'process_text_diff_html', $processed_line, $line, 'deleted' );
if ( $this->_show_split_view ) {
$r .= '<tr>' . $this->deletedLine( $line ) . $this->emptyLine() . "</tr>\n";
$r .= '<tr>' . $this->deletedLine( $line ) . "</tr>\n";
public function _context( $lines, $encode = true ) {
foreach ( $lines as $line ) {
$processed_line = htmlspecialchars( $line );
/** This filter is documented in wp-includes/wp-diff.php */
$line = apply_filters( 'process_text_diff_html', $processed_line, $line, 'unchanged' );
if ( $this->_show_split_view ) {
$r .= '<tr>' . $this->contextLine( $line ) . $this->contextLine( $line ) . "</tr>\n";
$r .= '<tr>' . $this->contextLine( $line ) . "</tr>\n";
* Process changed lines to do word-by-word diffs for extra highlighting.
* (TRAC style) sometimes these lines can actually be deleted or added rows.
* We do additional processing to figure that out
public function _changed( $orig, $final ) { // phpcs:ignore Universal.NamingConventions.NoReservedKeywordParameterNames.finalFound
* Does the aforementioned additional processing:
* *_matches tell what rows are "the same" in orig and final. Those pairs will be diffed to get word changes.
* - match is numeric: an index in other column.
* - match is 'X': no match. It is a new row.
* *_rows are column vectors for the orig column and the final column.
* - row >= 0: an index of the $orig or $final array.
* - row < 0: a blank row for that column.
list($orig_matches, $final_matches, $orig_rows, $final_rows) = $this->interleave_changed_lines( $orig, $final );
// These will hold the word changes as determined by an inline diff.
// Compute word diffs for each matched pair using the inline diff.
foreach ( $orig_matches as $o => $f ) {
if ( is_numeric( $o ) && is_numeric( $f ) ) {
$text_diff = new Text_Diff( 'auto', array( array( $orig[ $o ] ), array( $final[ $f ] ) ) );
$renderer = new $this->inline_diff_renderer();
$diff = $renderer->render( $text_diff );
// If they're too different, don't include any <ins> or <del>'s.
if ( preg_match_all( '!(<ins>.*?</ins>|<del>.*?</del>)!', $diff, $diff_matches ) ) {
// Length of all text between <ins> or <del>.
$stripped_matches = strlen( strip_tags( implode( ' ', $diff_matches[0] ) ) );
* Since we count length of text between <ins> or <del> (instead of picking just one),
* we double the length of chars not in those tags.
$stripped_diff = strlen( strip_tags( $diff ) ) * 2 - $stripped_matches;
$diff_ratio = $stripped_matches / $stripped_diff;
if ( $diff_ratio > $this->_diff_threshold ) {
continue; // Too different. Don't save diffs.
// Un-inline the diffs by removing <del> or <ins>.
$orig_diffs[ $o ] = preg_replace( '|<ins>.*?</ins>|', '', $diff );
$final_diffs[ $f ] = preg_replace( '|<del>.*?</del>|', '', $diff );
foreach ( array_keys( $orig_rows ) as $row ) {
// Both columns have blanks. Ignore them.
if ( $orig_rows[ $row ] < 0 && $final_rows[ $row ] < 0 ) {
// If we have a word based diff, use it. Otherwise, use the normal line.
if ( isset( $orig_diffs[ $orig_rows[ $row ] ] ) ) {
$orig_line = $orig_diffs[ $orig_rows[ $row ] ];
} elseif ( isset( $orig[ $orig_rows[ $row ] ] ) ) {
$orig_line = htmlspecialchars( $orig[ $orig_rows[ $row ] ] );
if ( isset( $final_diffs[ $final_rows[ $row ] ] ) ) {
$final_line = $final_diffs[ $final_rows[ $row ] ];
} elseif ( isset( $final[ $final_rows[ $row ] ] ) ) {
$final_line = htmlspecialchars( $final[ $final_rows[ $row ] ] );
if ( $orig_rows[ $row ] < 0 ) { // Orig is blank. This is really an added row.
$r .= $this->_added( array( $final_line ), false );
} elseif ( $final_rows[ $row ] < 0 ) { // Final is blank. This is really a deleted row.
$r .= $this->_deleted( array( $orig_line ), false );
} else { // A true changed row.
if ( $this->_show_split_view ) {
$r .= '<tr>' . $this->deletedLine( $orig_line ) . $this->addedLine( $final_line ) . "</tr>\n";
$r .= '<tr>' . $this->deletedLine( $orig_line ) . '</tr><tr>' . $this->addedLine( $final_line ) . "</tr>\n";
* Takes changed blocks and matches which rows in orig turned into which rows in final.
* @param array $orig Lines of the original version of the text.
* @param array $final Lines of the final version of the text.
* Array containing results of comparing the original text to the final text.
* @type array $orig_matches Associative array of original matches. Index == row
* number of `$orig`, value == corresponding row number
* of that same line in `$final` or 'x' if there is no
* corresponding row (indicating it is a deleted line).
* @type array $final_matches Associative array of final matches. Index == row
* number of `$final`, value == corresponding row number
* of that same line in `$orig` or 'x' if there is no
* corresponding row (indicating it is a new line).
* @type array $orig_rows Associative array of interleaved rows of `$orig` with
* blanks to keep matches aligned with side-by-side diff
* of `$final`. A value >= 0 corresponds to index of `$orig`.
* Value < 0 indicates a blank row.
* @type array $final_rows Associative array of interleaved rows of `$final` with
* blanks to keep matches aligned with side-by-side diff
* of `$orig`. A value >= 0 corresponds to index of `$final`.
* Value < 0 indicates a blank row.
public function interleave_changed_lines( $orig, $final ) { // phpcs:ignore Universal.NamingConventions.NoReservedKeywordParameterNames.finalFound
// Contains all pairwise string comparisons. Keys are such that this need only be a one dimensional array.
foreach ( array_keys( $orig ) as $o ) {
foreach ( array_keys( $final ) as $f ) {
$matches[ "$o,$f" ] = $this->compute_string_distance( $orig[ $o ], $final[ $f ] );
asort( $matches ); // Order by string distance.
$final_matches = array();
foreach ( $matches as $keys => $difference ) {
list($o, $f) = explode( ',', $keys );
// Already have better matches for these guys.
if ( isset( $orig_matches[ $o ] ) && isset( $final_matches[ $f ] ) ) {
// First match for these guys. Must be best match.
if ( ! isset( $orig_matches[ $o ] ) && ! isset( $final_matches[ $f ] ) ) {
$orig_matches[ $o ] = $f;
$final_matches[ $f ] = $o;
// Best match of this final is already taken? Must mean this final is a new row.
if ( isset( $orig_matches[ $o ] ) ) {
$final_matches[ $f ] = 'x';
} elseif ( isset( $final_matches[ $f ] ) ) {
// Best match of this orig is already taken? Must mean this orig is a deleted row.
$orig_matches[ $o ] = 'x';
// We read the text in this order.
// Stores rows and blanks for each column.
$orig_rows = array_keys( $orig_matches );
$orig_rows_copy = $orig_rows;
$final_rows = array_keys( $final_matches );
* Interleaves rows with blanks to keep matches aligned.
* We may end up with some extraneous blank rows, but we'll just ignore them later.
foreach ( $orig_rows_copy as $orig_row ) {
$final_pos = array_search( $orig_matches[ $orig_row ], $final_rows, true );
$orig_pos = (int) array_search( $orig_row, $orig_rows, true );
if ( false === $final_pos ) { // This orig is paired with a blank final.
array_splice( $final_rows, $orig_pos, 0, -1 );
} elseif ( $final_pos < $orig_pos ) { // This orig's match is up a ways. Pad final with blank rows.
$diff_array = range( -1, $final_pos - $orig_pos );
array_splice( $final_rows, $orig_pos, 0, $diff_array );
} elseif ( $final_pos > $orig_pos ) { // This orig's match is down a ways. Pad orig with blank rows.
$diff_array = range( -1, $orig_pos - $final_pos );
array_splice( $orig_rows, $orig_pos, 0, $diff_array );
// Pad the ends with blank rows if the columns aren't the same length.
$diff_count = count( $orig_rows ) - count( $final_rows );
while ( $diff_count < 0 ) {
array_push( $orig_rows, $diff_count++ );
} elseif ( $diff_count > 0 ) {
$diff_count = -1 * $diff_count;
while ( $diff_count < 0 ) {
array_push( $final_rows, $diff_count++ );
return array( $orig_matches, $final_matches, $orig_rows, $final_rows );
* Computes a number that is intended to reflect the "distance" between two strings.
public function compute_string_distance( $string1, $string2 ) {
// Use an md5 hash of the strings for a count cache, as it's fast to generate, and collisions aren't a concern.
$count_key1 = md5( $string1 );
$count_key2 = md5( $string2 );
// Cache vectors containing character frequency for all chars in each string.
if ( ! isset( $this->count_cache[ $count_key1 ] ) ) {
$this->count_cache[ $count_key1 ] = count_chars( $string1 );
if ( ! isset( $this->count_cache[ $count_key2 ] ) ) {
$this->count_cache[ $count_key2 ] = count_chars( $string2 );
It is recommended that you Edit text format, this type of Fix handles quite a lot in one request
