Handle empty comments in AJAX batches

src/js/_enqueues/admin/edit-comments.js

@@ -10,7 +10,7 @@
 /* global commentReply, theExtraList, theList, setCommentsList */
 
 (function($) {
-var getCount, updateCount, updateCountText, updatePending, updateApproved,
+var getCount, updateCount, updateCountText, updatePending, updateApproved, emptyComments,
 	updateHtmlTitle, updateDashboardText, updateInModerationText, adminTitle = document.title,
 	isDashboard = $('#dashboard_right_now').length,
 	titleDiv, titleRegEx,
@@ -178,6 +178,80 @@ var getCount, updateCount, updateCountText, updatePending, updateApproved,
 		}
 	};
 
+	/**
+	 * Empty spam or trash comments in AJAX batches.
+	 *
+	 * @since 6.9.0
+	 *
+	 * @param {Event} event Submit button click event.
+	 *
+	 * @return {void}
+	 */
+	emptyComments = function( event ) {
+		var button = $( event.currentTarget ),
+			form = button.closest( 'form' ),
+			status = form.find( 'input[name="comment_status"]' ).val(),
+			nonce = form.find( 'input[name="_wpnonce"]' ).val(),
+			timestamp = form.find( 'input[name="pagegen_timestamp"]' ).val(),
+			originalText = button.val(),
+			totalDeleted = 0,
+			notice;
+
+		if ( -1 === $.inArray( status, [ 'spam', 'trash' ] ) ) {
+			return;
+		}
+
+		event.preventDefault();
+
+		button.prop( 'disabled', true );
+		notice = $( '<span />', {
+			'class': 'empty-comments-progress screen-reader-text',
+			'aria-live': 'polite'
+		} ).insertAfter( button );
+
+		function runBatch() {
+			$.post(
+				ajaxurl,
+				{
+					action: 'empty-comments',
+					_ajax_nonce: nonce,
+					comment_status: status,
+					pagegen_timestamp: timestamp
+				}
+			).done( function( response ) {
+				var deleted, message;
+
+				if ( ! response.success ) {
+					button.prop( 'disabled', false ).val( originalText );
+					notice.remove();
+					window.alert( response.data && response.data.message ? response.data.message : __( 'An error occurred while emptying comments.' ) );
+					return;
+				}
+
+				deleted = parseInt( response.data.deleted, 10 ) || 0;
+				totalDeleted += deleted;
+				message = __( 'Emptying comments...' ) + ' ' + totalDeleted;
+
+				button.val( message );
+				notice.text( message );
+				wp.a11y.speak( message );
+
+				if ( response.data.done ) {
+					window.location.reload();
+					return;
+				}
+
+				runBatch();
+			} ).fail( function() {
+				button.prop( 'disabled', false ).val( originalText );
+				notice.remove();
+				window.alert( __( 'An error occurred while emptying comments.' ) );
+			} );
+		}
+
+		runBatch();
+	};
+
 	/**
 	 * Updates the title of the document with the number comments to be approved.
 	 *
@@ -1258,6 +1332,8 @@ $( function(){
 		e.preventDefault();
 	});
 
+	$( 'input[name="delete_all"]' ).on( 'click', emptyComments );
+
 	if ( typeof $.table_hotkeys != 'undefined' ) {
 		/**
 		 * Creates a function that navigates to a previous or next page.

src/wp-admin/admin-ajax.php

@@ -60,6 +60,7 @@
 	'oembed-cache',
 	'image-editor',
 	'delete-comment',
+	'empty-comments',
 	'delete-tag',
 	'delete-link',
 	'delete-meta',

src/wp-admin/includes/ajax-actions.php

@@ -720,6 +720,7 @@ function _wp_ajax_add_hierarchical_term() {
  * @since 3.1.0
  */
 function wp_ajax_delete_comment() {
+
 	$id = isset( $_POST['id'] ) ? (int) $_POST['id'] : 0;
 
 	$comment = get_comment( $id );
@@ -784,6 +785,82 @@ function wp_ajax_delete_comment() {
 	wp_die( 0 );
 }
 
+/**
+ * Handles emptying spam or trash comments via AJAX.
+ *
+ * @since 6.9.0
+ *
+ * @global wpdb $wpdb WordPress database abstraction object.
+ */
+function wp_ajax_empty_comments() {
+
+	global $wpdb;
+
+	check_ajax_referer( 'bulk-comments' );
+
+	if ( ! current_user_can( 'moderate_comments' ) ) {
+		wp_send_json_error( array( 'message' => __( 'Sorry, you are not allowed to moderate comments on this site.' ) ), 403 );
+	}
+
+	$comment_status = isset( $_POST['comment_status'] ) ? sanitize_key( wp_unslash( $_POST['comment_status'] ) ) : '';
+
+	if ( ! in_array( $comment_status, array( 'spam', 'trash' ), true ) ) {
+		wp_send_json_error( array( 'message' => __( 'Invalid comment status.' ) ), 400 );
+	}
+
+	$delete_time = isset( $_POST['pagegen_timestamp'] ) ? sanitize_text_field( wp_unslash( $_POST['pagegen_timestamp'] ) ) : '';
+
+	if ( '' === $delete_time ) {
+		wp_send_json_error( array( 'message' => __( 'Missing delete timestamp.' ) ), 400 );
+	}
+
+	$batch_size  = (int) apply_filters( 'wp_empty_comments_batch_size', 20, $comment_status );
+	$batch_size  = max( 1, min( 100, $batch_size ) );
+	$deleted     = 0;
+	$comment_ids = $wpdb->get_col(
+		$wpdb->prepare(
+			"SELECT comment_ID FROM $wpdb->comments
+			WHERE comment_approved = %s AND %s > comment_date_gmt
+			ORDER BY comment_ID ASC
+			LIMIT %d",
+			$comment_status,
+			$delete_time,
+			$batch_size
+		)
+	);
+
+	wp_defer_comment_counting( true );
+
+	foreach ( $comment_ids as $comment_id ) {
+		if ( ! current_user_can( 'edit_comment', $comment_id ) ) {
+			continue;
+		}
+
+		if ( wp_delete_comment( $comment_id ) ) {
+			++$deleted;
+		}
+	}
+
+	wp_defer_comment_counting( false );
+
+	$remaining = (int) $wpdb->get_var(
+		$wpdb->prepare(
+			"SELECT COUNT(*) FROM $wpdb->comments
+			WHERE comment_approved = %s AND %s > comment_date_gmt",
+			$comment_status,
+			$delete_time
+		)
+	);
+
+	wp_send_json_success(
+		array(
+			'deleted'   => $deleted,
+			'remaining' => $remaining,
+			'done'      => 0 === $remaining || ( 0 === $deleted && ! empty( $comment_ids ) ),
+		)
+	);
+}
+
 /**
  * Handles deleting a tag via AJAX.
  *