1<?php
  2/**
  3 * WordPress Administration Revisions API
  4 *
  5 * @package WordPress
  6 * @subpackage Administration
  7 * @since 3.6.0
  8 */
  9
 10/**
 11 * Get the revision UI diff.
 12 *
 13 * @since 3.6.0
 14 *
 15 * @param WP_Post|int $post         The post object or post ID.
 16 * @param int         $compare_from The revision ID to compare from.
 17 * @param int         $compare_to   The revision ID to come to.
 18 * @return array|false Associative array of a post's revisioned fields and their diffs.
 19 *                     Or, false on failure.
 20 */
 21function wp_get_revision_ui_diff( $post, $compare_from, $compare_to ) {
 22	$post = get_post( $post );
 23	if ( ! $post ) {
 24		return false;
 25	}
 26
 27	if ( $compare_from ) {
 28		$compare_from = get_post( $compare_from );
 29		if ( ! $compare_from ) {
 30			return false;
 31		}
 32	} else {
 33		// If we're dealing with the first revision...
 34		$compare_from = false;
 35	}
 36
 37	$compare_to = get_post( $compare_to );
 38	if ( ! $compare_to ) {
 39		return false;
 40	}
 41
 42	/*
 43	 * If comparing revisions, make sure we are dealing with the right post parent.
 44	 * The parent post may be a 'revision' when revisions are disabled and we're looking at autosaves.
 45	 */
 46	if ( $compare_from && $compare_from->post_parent !== $post->ID && $compare_from->ID !== $post->ID ) {
 47		return false;
 48	}
 49	if ( $compare_to->post_parent !== $post->ID && $compare_to->ID !== $post->ID ) {
 50		return false;
 51	}
 52
 53	if ( $compare_from && strtotime( $compare_from->post_date_gmt ) > strtotime( $compare_to->post_date_gmt ) ) {
 54		$temp         = $compare_from;
 55		$compare_from = $compare_to;
 56		$compare_to   = $temp;
 57	}
 58
 59	// Add default title if title field is empty.
 60	if ( $compare_from && empty( $compare_from->post_title ) ) {
 61		$compare_from->post_title = __( '(no title)' );
 62	}
 63	if ( empty( $compare_to->post_title ) ) {
 64		$compare_to->post_title = __( '(no title)' );
 65	}
 66
 67	$return = array();
 68
 69	foreach ( _wp_post_revision_fields( $post ) as $field => $name ) {
 70		/**
 71		 * Contextually filter a post revision field.
 72		 *
 73		 * The dynamic portion of the hook name, `$field`, corresponds to a name of a
 74		 * field of the revision object.
 75		 *
 76		 * Possible hook names include:
 77		 *
 78		 *  - `_wp_post_revision_field_post_title`
 79		 *  - `_wp_post_revision_field_post_content`
 80		 *  - `_wp_post_revision_field_post_excerpt`
 81		 *
 82		 * @since 3.6.0
 83		 *
 84		 * @param string  $revision_field The current revision field to compare to or from.
 85		 * @param string  $field          The current revision field.
 86		 * @param WP_Post $compare_from   The revision post object to compare to or from.
 87		 * @param string  $context        The context of whether the current revision is the old
 88		 *                                or the new one. Either 'to' or 'from'.
 89		 */
 90		$content_from = $compare_from ? apply_filters( "_wp_post_revision_field_{$field}", $compare_from->$field, $field, $compare_from, 'from' ) : '';
 91
 92		/** This filter is documented in wp-admin/includes/revision.php */
 93		$content_to = apply_filters( "_wp_post_revision_field_{$field}", $compare_to->$field, $field, $compare_to, 'to' );
 94
 95		$args = array(
 96			'show_split_view' => true,
 97			'title_left'      => __( 'Removed' ),
 98			'title_right'     => __( 'Added' ),
 99		);
100
101		/**
102		 * Filters revisions text diff options.
103		 *
104		 * Filters the options passed to wp_text_diff() when viewing a post revision.
105		 *
106		 * @since 4.1.0
107		 *
108		 * @param array   $args {
109		 *     Associative array of options to pass to wp_text_diff().
110		 *
111		 *     @type bool $show_split_view True for split view (two columns), false for
112		 *                                 un-split view (single column). Default true.
113		 * }
114		 * @param string  $field        The current revision field.
115		 * @param WP_Post $compare_from The revision post to compare from.
116		 * @param WP_Post $compare_to   The revision post to compare to.
117		 */
118		$args = apply_filters( 'revision_text_diff_options', $args, $field, $compare_from, $compare_to );
119
120		$diff = wp_text_diff( $content_from, $content_to, $args );
121
122		if ( ! $diff && 'post_title' === $field ) {
123			/*
124			 * It's a better user experience to still show the Title, even if it didn't change.
125			 * No, you didn't see this.
126			 */
127			$diff = '<table class="diff"><colgroup><col class="content diffsplit left"><col class="content diffsplit middle"><col class="content diffsplit right"></colgroup><tbody><tr>';
128
129			// In split screen mode, show the title before/after side by side.
130			if ( true === $args['show_split_view'] ) {
131				$diff .= '<td>' . esc_html( $compare_from->post_title ) . '</td><td></td><td>' . esc_html( $compare_to->post_title ) . '</td>';
132			} else {
133				$diff .= '<td>' . esc_html( $compare_from->post_title ) . '</td>';
134
135				// In single column mode, only show the title once if unchanged.
136				if ( $compare_from->post_title !== $compare_to->post_title ) {
137					$diff .= '</tr><tr><td>' . esc_html( $compare_to->post_title ) . '</td>';
138				}
139			}
140
141			$diff .= '</tr></tbody>';
142			$diff .= '</table>';
143		}
144
145		if ( $diff ) {
146			$return[] = array(
147				'id'   => $field,
148				'name' => $name,
149				'diff' => $diff,
150			);
151		}
152	}
153
154	/**
155	 * Filters the fields displayed in the post revision diff UI.
156	 *
157	 * @since 4.1.0
158	 *
159	 * @param array[] $return       Array of revision UI fields. Each item is an array of id, name, and diff.
160	 * @param WP_Post $compare_from The revision post to compare from.
161	 * @param WP_Post $compare_to   The revision post to compare to.
162	 */
163	return apply_filters( 'wp_get_revision_ui_diff', $return, $compare_from, $compare_to );
164}
165
166/**
167 * Prepare revisions for JavaScript.
168 *
169 * @since 3.6.0
170 *
171 * @param WP_Post|int $post                 The post object or post ID.
172 * @param int         $selected_revision_id The selected revision ID.
173 * @param int         $from                 Optional. The revision ID to compare from.
174 * @return array An associative array of revision data and related settings.
175 */
176function wp_prepare_revisions_for_js( $post, $selected_revision_id, $from = null ) {
177	$post    = get_post( $post );
178	$authors = array();
179	$now_gmt = time();
180
181	$revisions = wp_get_post_revisions(
182		$post->ID,
183		array(
184			'order'         => 'ASC',
185			'check_enabled' => false,
186		)
187	);
188	// If revisions are disabled, we only want autosaves and the current post.
189	if ( ! wp_revisions_enabled( $post ) ) {
190		foreach ( $revisions as $revision_id => $revision ) {
191			if ( ! wp_is_post_autosave( $revision ) ) {
192				unset( $revisions[ $revision_id ] );
193			}
194		}
195		$revisions = array( $post->ID => $post ) + $revisions;
196	}
197
198	$show_avatars = get_option( 'show_avatars' );
199
200	update_post_author_caches( $revisions );
201
202	$can_restore = current_user_can( 'edit_post', $post->ID );
203	$current_id  = false;
204
205	foreach ( $revisions as $revision ) {
206		$modified     = strtotime( $revision->post_modified );
207		$modified_gmt = strtotime( $revision->post_modified_gmt . ' +0000' );
208		if ( $can_restore ) {
209			$restore_link = str_replace(
210				'&amp;',
211				'&',
212				wp_nonce_url(
213					add_query_arg(
214						array(
215							'revision' => $revision->ID,
216							'action'   => 'restore',
217						),
218						admin_url( 'revision.php' )
219					),
220					"restore-post_{$revision->ID}"
221				)
222			);
223		}
224
225		if ( ! isset( $authors[ $revision->post_author ] ) ) {
226			$authors[ $revision->post_author ] = array(
227				'id'     => (int) $revision->post_author,
228				'avatar' => $show_avatars ? get_avatar( $revision->post_author, 32 ) : '',
229				'name'   => get_the_author_meta( 'display_name', $revision->post_author ),
230			);
231		}
232
233		$autosave = (bool) wp_is_post_autosave( $revision );
234		$current  = ! $autosave && $revision->post_modified_gmt === $post->post_modified_gmt;
235		if ( $current && ! empty( $current_id ) ) {
236			// If multiple revisions have the same post_modified_gmt, highest ID is current.
237			if ( $current_id < $revision->ID ) {
238				$revisions[ $current_id ]['current'] = false;
239				$current_id                          = $revision->ID;
240			} else {
241				$current = false;
242			}
243		} elseif ( $current ) {
244			$current_id = $revision->ID;
245		}
246
247		$revisions_data = array(
248			'id'         => $revision->ID,
249			'title'      => get_the_title( $post->ID ),
250			'author'     => $authors[ $revision->post_author ],
251			'date'       => date_i18n( __( 'M j, Y @ H:i' ), $modified ),
252			'dateShort'  => date_i18n( _x( 'j M Y @ H:i', 'revision date short format' ), $modified ),
253			/* translators: %s: Human-readable time difference. */
254			'timeAgo'    => sprintf( __( '%s ago' ), human_time_diff( $modified_gmt, $now_gmt ) ),
255			'autosave'   => $autosave,
256			'current'    => $current,
257			'restoreUrl' => $can_restore ? $restore_link : false,
258		);
259
260		/**
261		 * Filters the array of revisions used on the revisions screen.
262		 *
263		 * @since 4.4.0
264		 *
265		 * @param array   $revisions_data {
266		 *     The bootstrapped data for the revisions screen.
267		 *
268		 *     @type int        $id         Revision ID.
269		 *     @type string     $title      Title for the revision's parent WP_Post object.
270		 *     @type int        $author     Revision post author ID.
271		 *     @type string     $date       Date the revision was modified.
272		 *     @type string     $dateShort  Short-form version of the date the revision was modified.
273		 *     @type string     $timeAgo    GMT-aware amount of time ago the revision was modified.
274		 *     @type bool       $autosave   Whether the revision is an autosave.
275		 *     @type bool       $current    Whether the revision is both not an autosave and the post
276		 *                                  modified date matches the revision modified date (GMT-aware).
277		 *     @type bool|false $restoreUrl URL if the revision can be restored, false otherwise.
278		 * }
279		 * @param WP_Post $revision       The revision's WP_Post object.
280		 * @param WP_Post $post           The revision's parent WP_Post object.
281		 */
282		$revisions[ $revision->ID ] = apply_filters( 'wp_prepare_revision_for_js', $revisions_data, $revision, $post );
283	}
284
285	/*
286	 * If we only have one revision, the initial revision is missing. This happens
287	 * when we have an autosave and the user has clicked 'View the Autosave'.
288	 */
289	if ( 1 === count( $revisions ) ) {
290		$revisions[ $post->ID ] = array(
291			'id'         => $post->ID,
292			'title'      => get_the_title( $post->ID ),
293			'author'     => $authors[ $revision->post_author ],
294			'date'       => date_i18n( __( 'M j, Y @ H:i' ), strtotime( $post->post_modified ) ),
295			'dateShort'  => date_i18n( _x( 'j M @ H:i', 'revision date short format' ), strtotime( $post->post_modified ) ),
296			/* translators: %s: Human-readable time difference. */
297			'timeAgo'    => sprintf( __( '%s ago' ), human_time_diff( strtotime( $post->post_modified_gmt ), $now_gmt ) ),
298			'autosave'   => false,
299			'current'    => true,
300			'restoreUrl' => false,
301		);
302		$current_id             = $post->ID;
303	}
304
305	/*
306	 * If a post has been saved since the latest revision (no revisioned fields
307	 * were changed), we may not have a "current" revision. Mark the latest
308	 * revision as "current".
309	 */
310	if ( empty( $current_id ) ) {
311		if ( $revisions[ $revision->ID ]['autosave'] ) {
312			$revision = end( $revisions );
313			while ( $revision['autosave'] ) {
314				$revision = prev( $revisions );
315			}
316			$current_id = $revision['id'];
317		} else {
318			$current_id = $revision->ID;
319		}
320		$revisions[ $current_id ]['current'] = true;
321	}
322
323	// Now, grab the initial diff.
324	$compare_two_mode = is_numeric( $from );
325	if ( ! $compare_two_mode ) {
326		$found = array_search( $selected_revision_id, array_keys( $revisions ), true );
327		if ( $found ) {
328			$from = array_keys( array_slice( $revisions, $found - 1, 1, true ) );
329			$from = reset( $from );
330		} else {
331			$from = 0;
332		}
333	}
334
335	$from = absint( $from );
336
337	$diffs = array(
338		array(
339			'id'     => $from . ':' . $selected_revision_id,
340			'fields' => wp_get_revision_ui_diff( $post->ID, $from, $selected_revision_id ),
341		),
342	);
343
344	return array(
345		'postId'         => $post->ID,
346		'nonce'          => wp_create_nonce( 'revisions-ajax-nonce' ),
347		'revisionData'   => array_values( $revisions ),
348		'to'             => $selected_revision_id,
349		'from'           => $from,
350		'diffData'       => $diffs,
351		'baseUrl'        => parse_url( admin_url( 'revision.php' ), PHP_URL_PATH ),
352		'compareTwoMode' => absint( $compare_two_mode ), // Apparently booleans are not allowed.
353		'revisionIds'    => array_keys( $revisions ),
354	);
355}
356
357/**
358 * Print JavaScript templates required for the revisions experience.
359 *
360 * @since 4.1.0
361 *
362 * @global WP_Post $post Global post object.
363 */
364function wp_print_revision_templates() {
365	global $post;
366	?><script id="tmpl-revisions-frame" type="text/html">
367		<div class="revisions-control-frame"></div>
368		<div class="revisions-diff-frame"></div>
369	</script>
370
371	<script id="tmpl-revisions-buttons" type="text/html">
372		<div class="revisions-previous">
373			<input class="button" type="button" value="<?php echo esc_attr_x( 'Previous', 'Button label for a previous revision' ); ?>" />
374		</div>
375
376		<div class="revisions-next">
377			<input class="button" type="button" value="<?php echo esc_attr_x( 'Next', 'Button label for a next revision' ); ?>" />
378		</div>
379	</script>
380
381	<script id="tmpl-revisions-slider-hidden-help" type="text/html">
382		<h2 class="screen-reader-text"><?php esc_html_e( 'Select a revision' ); ?></h2>
383		<p id="revisions-slider-hidden-help" hidden><?php esc_html_e( 'Change revision by using the left and right arrow keys' ); ?></p>
384	</script>
385
386	<script id="tmpl-revisions-checkbox" type="text/html">
387		<div class="revision-toggle-compare-mode">
388			<label>
389				<input type="checkbox" class="compare-two-revisions"
390				<#
391				if ( 'undefined' !== typeof data && data.model.attributes.compareTwoMode ) {
392					#> checked="checked"<#
393				}
394				#>
395				/>
396				<?php esc_html_e( 'Compare any two revisions' ); ?>
397			</label>
398		</div>
399	</script>
400
401	<script id="tmpl-revisions-meta" type="text/html">
402		<# if ( ! _.isUndefined( data.attributes ) ) { #>
403			<div class="diff-title">
404				<# if ( 'from' === data.type ) { #>
405					<strong id="diff-title-from"><?php _ex( 'From:', 'Followed by post revision info' ); ?></strong>
406				<# } else if ( 'to' === data.type ) { #>
407					<strong id="diff-title-to"><?php _ex( 'To:', 'Followed by post revision info' ); ?></strong>
408				<# } #>
409				<div class="author-card<# if ( data.attributes.autosave ) { #> autosave<# } #>">
410					<div>
411						{{{ data.attributes.author.avatar }}}
412						<div class="author-info" id="diff-title-author">
413						<# if ( data.attributes.autosave ) { #>
414							<span class="byline">
415							<?php
416							printf(
417								/* translators: %s: User's display name. */
418								__( 'Autosave by %s' ),
419								'<span class="author-name">{{ data.attributes.author.name }}</span>'
420							);
421							?>
422								</span>
423						<# } else if ( data.attributes.current ) { #>
424							<span class="byline">
425							<?php
426							printf(
427								/* translators: %s: User's display name. */
428								__( 'Current Revision by %s' ),
429								'<span class="author-name">{{ data.attributes.author.name }}</span>'
430							);
431							?>
432								</span>
433						<# } else { #>
434							<span class="byline">
435							<?php
436							printf(
437								/* translators: %s: User's display name. */
438								__( 'Revision by %s' ),
439								'<span class="author-name">{{ data.attributes.author.name }}</span>'
440							);
441							?>
442								</span>
443						<# } #>
444							<span class="time-ago">{{ data.attributes.timeAgo }}</span>
445							<span class="date">({{ data.attributes.dateShort }})</span>
446						</div>
447					</div>
448				<# if ( 'to' === data.type && data.attributes.restoreUrl ) { #>
449					<input  <?php if ( wp_check_post_lock( $post->ID ) ) { ?>
450						disabled="disabled"
451					<?php } else { ?>
452						<# if ( data.attributes.current ) { #>
453							disabled="disabled"
454						<# } #>
455					<?php } ?>
456					<# if ( data.attributes.autosave ) { #>
457						type="button" class="restore-revision button button-primary" value="<?php esc_attr_e( 'Restore This Autosave' ); ?>" />
458					<# } else { #>
459						type="button" class="restore-revision button button-primary" value="<?php esc_attr_e( 'Restore This Revision' ); ?>" />
460					<# } #>
461				<# } #>
462			</div>
463		<# if ( 'tooltip' === data.type ) { #>
464			<div class="revisions-tooltip-arrow"><span></span></div>
465		<# } #>
466	<# } #>
467	</script>
468
469	<script id="tmpl-revisions-diff" type="text/html">
470		<div class="loading-indicator"><span class="spinner"></span></div>
471		<div class="diff-error"><?php _e( 'An error occurred while loading the comparison. Please refresh the page and try again.' ); ?></div>
472		<div class="diff">
473		<# _.each( data.fields, function( field ) { #>
474			<h2>{{ field.name }}</h2>
475			{{{ field.diff }}}
476		<# }); #>
477		</div>
478	</script>
479	<?php
480}
481