Ticket #33717: 33717.15.patch

src/wp-admin/comment.php

@@ -165 +165 @@
                 ?>
 <div id="message" class="notice notice-warning"><p><strong><?php _e( 'Caution:' ); ?></strong> <?php echo $caution_msg; ?></p></div>
 
+<?php
+if ( 0 === (int) $comment->comment_approved && true === (bool) get_comment_meta( $comment->comment_ID, '_wp_comment_author_notification_optin', true ) ) :
+        ?>
+        <div id="message" class="notice notice-warning">
+                <p>
+                        <?php
+                        /* translators: %s is the comment author name. */
+                        printf( esc_html__( '%s has opted in to receive a notification on comment’s approval.' ), get_comment_author( $comment ) );
+                        ?>
+                </p>
+        </div>
+<?php endif; ?>
+
 <table class="form-table comment-ays">
 <tr>
 <th scope="row"><?php _e( 'Author' ); ?></th>

src/wp-admin/css/dashboard.css

@@ -821 +821 @@
         position: relative;
 }
 
+#activity-widget #the-comment-list .comment-item .attention {
+        display: none;
+        color: #d54e21;
+        font-size: 90%;
+}
+
 #activity-widget #the-comment-list .avatar {
         position: absolute;
         top: 12px;
@@ -857 +863 @@
         width: 4px;
 }
 
+#activity-widget #the-comment-list .unapproved .attention {
+        display: block;
+}
+
 #activity-widget #the-comment-list .spam-undo-inside .avatar,
 #activity-widget #the-comment-list .trash-undo-inside .avatar {
         position: relative;

src/wp-admin/css/list-tables.css

@@ -217 +217 @@
         background-color: #f5f5f5;
 }
 
+#the-comment-list .comment .attention {
+        display: none;
+        color: #d54e21;
+        font-size: 90%;
+}
+
 #the-comment-list .unapproved th,
 #the-comment-list .unapproved td {
         background-color: #fef7f1;
@@ -230 +236 @@
         margin-left: 4px;
 }
 
+#the-comment-list .comment.unapproved .attention {
+        display: block;
+}
+
 #the-comment-list .approve a {
         color: #006505;
 }

src/wp-admin/edit-form-comment.php

@@ -16 +16 @@
 <div class="wrap">
 <h1><?php _e( 'Edit Comment' ); ?></h1>
 
+<?php
+if ( 0 === (int) $comment->comment_approved && true === (bool) get_comment_meta( $comment->comment_ID, '_wp_comment_author_notification_optin', true ) ) :
+        ?>
+        <div id="message" class="notice notice-warning">
+                <p>
+                        <?php
+                        /* translators: %s is the comment author name. */
+                        printf( esc_html__( '%s has opted in to receive a notification on comment’s approval.' ), get_comment_author( $comment ) );
+                        ?>
+                </p>
+        </div>
+<?php endif; ?>
+
 <div id="poststuff">
 <input type="hidden" name="action" value="editedcomment" />
 <input type="hidden" name="comment_ID" value="<?php echo esc_attr( $comment->comment_ID ); ?>" />

src/wp-admin/includes/class-wp-comments-list-table.php

@@ -882 +882 @@
                         }
                 }
 
+                if ( 0 === (int) $comment->comment_approved && true === (bool) get_comment_meta( $comment->comment_ID, '_wp_comment_author_notification_optin', true ) ) {
+                        /* translators: %s is the comment author name. */
+                        echo '<p class="attention"><span class="dashicons dashicons-info"></span> ' . sprintf( esc_html__( '%s has opted in to receive a notification on comment’s approval.' ), get_comment_author( $comment ) ) . '</p>';
+                }
+
                 comment_text( $comment );
 
                 if ( $this->user_can ) {

src/wp-admin/includes/dashboard.php

@@ -827 +827 @@
                                 }
                                 ?>
                         </p>
-
                                 <?php
+                                if ( 0 === (int) $comment->comment_approved && true === (bool) get_comment_meta( $comment->comment_ID, '_wp_comment_author_notification_optin', true ) ) :
+                                        ?>
+                                                <p class="attention">
+                                                        <span class="dashicons dashicons-info"></span>
+                                                        <?php
+                                                        /* translators: %s is the comment author name. */
+                                                        printf( esc_html__( '%s has opted in to receive a notification on comment’s approval.' ), get_comment_author( $comment ) );
+                                                        ?>
+                                                </p>
+                                        <?php
+                                        endif;
+
                         else :
                                 switch ( $comment->comment_type ) {
                                         case 'pingback':

src/wp-comments-post.php

@@ -22 +22 @@
 
 nocache_headers();
 
-$comment = wp_handle_comment_submission( wp_unslash( $_POST ) );
-if ( is_wp_error( $comment ) ) {
-        $data = (int) $comment->get_error_data();
-        if ( ! empty( $data ) ) {
+if ( isset( $_POST['wp-comment-approved-notification-optin'], $_POST['comment_ID'], $_POST['moderation-hash'] ) ) {
+        $comment = get_comment( $_POST['comment_ID'] );
+
+        if ( ! is_null( $comment->comment_ID ) && hash_equals( $_POST['moderation-hash'], wp_hash( $comment->comment_date_gmt ) ) ) {
+                update_comment_meta( $comment->comment_ID, '_wp_comment_author_notification_optin', true );
+        } else {
                 wp_die(
-                        '<p>' . $comment->get_error_message() . '</p>',
-                        __( 'Comment Submission Failure' ),
+                        '<p>' . __( 'Sorry we haven’t found your comment.' ) . '</p>',
+                        __( 'Comment Notification opt-in failure' ),
                         array(
-                                'response'  => $data,
                                 'back_link' => true,
                         )
                 );
-        } else {
-                exit;
         }
-}
+} else {
+        $comment = wp_handle_comment_submission( wp_unslash( $_POST ) );
+        if ( is_wp_error( $comment ) ) {
+                $data = (int) $comment->get_error_data();
+                if ( ! empty( $data ) ) {
+                        wp_die(
+                                '<p>' . $comment->get_error_message() . '</p>',
+                                __( 'Comment Submission Failure' ),
+                                array(
+                                        'response'  => $data,
+                                        'back_link' => true,
+                                )
+                        );
+                } else {
+                        exit;
+                }
+        }
 
-$user            = wp_get_current_user();
-$cookies_consent = ( isset( $_POST['wp-comment-cookies-consent'] ) );
+        $user            = wp_get_current_user();
+        $cookies_consent = ( isset( $_POST['wp-comment-cookies-consent'] ) );
 
-/**
- * Perform other actions when comment cookies are set.
- *
- * @since 3.4.0
- * @since 4.9.6 The `$cookies_consent` parameter was added.
- *
- * @param WP_Comment $comment         Comment object.
- * @param WP_User    $user            Comment author's user object. The user may not exist.
- * @param bool       $cookies_consent Comment author's consent to store cookies.
- */
-do_action( 'set_comment_cookies', $comment, $user, $cookies_consent );
+        /**
+         * Perform other actions when comment cookies are set.
+         *
+         * @since 3.4.0
+         * @since 4.9.6 The `$cookies_consent` parameter was added.
+         *
+         * @param WP_Comment $comment         Comment object.
+         * @param WP_User    $user            Comment author's user object. The user may not exist.
+         * @param bool       $cookies_consent Comment author's consent to store cookies.
+         */
+        do_action( 'set_comment_cookies', $comment, $user, $cookies_consent );
+}
 
 $location = empty( $_POST['redirect_to'] ) ? get_comment_link( $comment ) : $_POST['redirect_to'] . '#comment-' . $comment->comment_ID;
 

src/wp-includes/class-walker-comment.php

@@ -40 +40 @@
                 'id'     => 'comment_ID',
         );
 
+        /**
+         * Backward compability checks.
+         *
+         * @since 5.7.0
+         * @var array
+         */
+        public $backcompat = array(
+                'needs_comment_approval_notification_output' => true,
+        );
+
         /**
          * Starts the list before the elements are added.
          *
@@ -259 +269 @@
          * to the comment cookies.
          *
          * @since 5.4.2
+         * @since 5.7.0 Adds backcompatibilty output if needed.
          *
          * @param string          $comment_text Text of the current comment.
          * @param WP_Comment|null $comment      The comment object. Null if not found.
@@ -272 +283 @@
                         $comment_text = wp_kses( $comment_text, array() );
                 }
 
+                /*
+                 * Checks if we need to output the comment approval notification/form.
+                 */
+                if ( $this->backcompat['needs_comment_approval_notification_output'] ) {
+                        $comment_text = $this->comment_approval_notification_form( $comment, true ) . "\n" . $comment_text;
+                }
+
                 return $comment_text;
         }
 
+        /**
+         * Outputs the awaiting moderation text.
+         *
+         * @since 5.7.0
+         *
+         * @param WP_Comment $comment Comment to display.
+         */
+        protected function awaiting_moderation_text( $comment ) {
+
+                if ( "0" === $comment->comment_approved ) {
+                        $commenter = wp_get_current_commenter();
+                        if ( $commenter['comment_author_email'] ) {
+                                $moderation_note = __( 'Your comment is awaiting moderation.' );
+                        } else {
+                                $moderation_note = __( 'Your comment is awaiting moderation. This is a preview, your comment will be visible after it has been approved.' );
+                        }
+
+                        printf( '<em class="comment-awaiting-moderation">%s</em>', esc_html( $moderation_note ) );
+                }
+        }
+
+        /**
+         * Gets the comment's approval notification/form.
+         *
+         * @since 5.7.0
+         *
+         * @param WP_Comment $comment Comment to display.
+         * @param bool $skip_backcompat True to skip the backward compability output.
+         *                              False otherwise.
+         * @return string HTML Output.
+         */
+        protected function comment_approval_notification_form( $comment, $skip_backcompat = false ) {
+                $comment_approval_output = '';
+
+                if ( "0" === $comment->comment_approved && has_action( 'comment_unapproved_to_approved', 'wp_new_comment_notify_comment_author' ) ) {
+                        if ( true === (bool) get_comment_meta( $comment->comment_ID, '_wp_comment_author_notification_optin', true ) ) {
+                                $comment_approval_output = sprintf(
+                                        '<p><em class="wp-comment-approved-notification-optedin">%s</em></p>',
+                                        esc_html__( 'You will receive an email when your comment has been approved.' )
+                                );
+                        } else {
+                                $comment_approval_output = sprintf(
+                                        '<form action="%1$s" method="post">
+                                                <p>
+                                                        <label for="wp-comment-approved-notification-optin">
+                                                                <input type="checkbox" id="wp-comment-approved-notification-optin" name="wp-comment-approved-notification-optin">
+                                                                %2$s
+                                                        </label>
+                                                </p>
+                                                <input type="hidden" name="comment_ID" value="%3$s">
+                                                <input type="hidden" name="moderation-hash" value="%4$s">
+                                                <input type="submit" class="button" value="%5$s">
+                                        </form>',
+                                        esc_url( site_url( '/wp-comments-post.php' ) ),
+                                        esc_html__( 'I want to be notified by email when my comment is approved.' ),
+                                        absint( $comment->comment_ID ),
+                                        wp_hash( $comment->comment_date_gmt ),
+                                        esc_html_x( 'Save', 'comment approved notification form' )
+                                );
+                        }
+                }
+
+                // Skip the backcompat output.
+                if ( $skip_backcompat ) {
+                        $this->backcompat['needs_comment_approval_notification_output'] = false;
+                }
+
+                // Return the approval notification/form.
+                return $comment_approval_output;
+        }
+
         /**
          * Outputs a single comment.
          *
@@ -297 +386 @@
 
                 $commenter          = wp_get_current_commenter();
                 $show_pending_links = isset( $commenter['comment_author'] ) && $commenter['comment_author'];
-
-                if ( $commenter['comment_author_email'] ) {
-                        $moderation_note = __( 'Your comment is awaiting moderation.' );
-                } else {
-                        $moderation_note = __( 'Your comment is awaiting moderation. This is a preview; your comment will be visible after it has been approved.' );
-                }
                 ?>
                 <<?php echo $tag; ?> <?php comment_class( $this->has_children ? 'parent' : '', $comment ); ?> id="comment-<?php comment_ID(); ?>">
                 <?php if ( 'div' !== $args['style'] ) : ?>
@@ -328 +411 @@
                         );
                         ?>
                 </div>
-                <?php if ( '0' == $comment->comment_approved ) : ?>
-                <em class="comment-awaiting-moderation"><?php echo $moderation_note; ?></em>
-                <br />
-                <?php endif; ?>
+
+                <?php
+                // Output the comment moderation feedback if needed.
+                $this->awaiting_moderation_text( $comment );
+
+                // Output the comment approval notification form if needed.
+                echo $this->comment_approval_notification_form( $comment, true );
+                ?>
 
                 <div class="comment-meta commentmetadata">
                         <?php
@@ -401 +488 @@
 
                 $commenter          = wp_get_current_commenter();
                 $show_pending_links = ! empty( $commenter['comment_author'] );
-
-                if ( $commenter['comment_author_email'] ) {
-                        $moderation_note = __( 'Your comment is awaiting moderation.' );
-                } else {
-                        $moderation_note = __( 'Your comment is awaiting moderation. This is a preview; your comment will be visible after it has been approved.' );
-                }
                 ?>
                 <<?php echo $tag; ?> id="comment-<?php comment_ID(); ?>" <?php comment_class( $this->has_children ? 'parent' : '', $comment ); ?>>
                         <article id="div-comment-<?php comment_ID(); ?>" class="comment-body">
@@ -450 +531 @@
                                                 ?>
                                         </div><!-- .comment-metadata -->
 
-                                        <?php if ( '0' == $comment->comment_approved ) : ?>
-                                        <em class="comment-awaiting-moderation"><?php echo $moderation_note; ?></em>
-                                        <?php endif; ?>
+                                        <?php
+                                        // Output the comment moderation feedback if needed.
+                                        $this->awaiting_moderation_text( $comment );
+
+                                        // Output the comment approval notification form if needed.
+                                        echo $this->comment_approval_notification_form( $comment, true );
+                                        ?>
                                 </footer><!-- .comment-meta -->
 
                                 <div class="comment-content">

src/wp-includes/comment.php

@@ -2348 +2348 @@
         return wp_notify_postauthor( $comment_ID );
 }
 
+/**
+ * Notify a comment author when their comment gets approved.
+ *
+ * This notification is only sent once when the comment status
+ * changes from unapproved to approved.
+ *
+ * @since 5.7.0
+ *
+ * @param int|WP_Comment $comment_id Comment ID or WP_Comment object.
+ * @return bool Whether the email was sent successfully.
+ */
+function wp_new_comment_notify_comment_author( $comment_id ) {
+        $comment = get_comment( $comment_id );
+
+        if ( ! $comment ) {
+                return false;
+        }
+
+        $post           = get_post( $comment->comment_post_ID );
+        $comment_author = get_user_by( 'email', $comment->comment_author_email );
+
+        if ( ! $post ) {
+                return false;
+        }
+
+        // Make sure the comment author can be notified by email.
+        if ( empty( $comment->comment_author_email ) ) {
+                return false;
+        }
+
+        if ( true !== (bool) get_comment_meta( $comment->comment_ID, '_wp_comment_author_notification_optin', true ) ) {
+                return false;
+        }
+
+        /**
+         * The blogname option is escaped with esc_html when
+         * saved into the database, we need to reverse this for
+         * the plain text area of the email.
+         */
+        $blogname = wp_specialchars_decode( get_option( 'blogname' ), ENT_QUOTES );
+
+        /* translators: 1: blog name, 2: post title */
+        $subject = sprintf( __( '[%1$s] Your comment on "%2$s" has been approved' ), $blogname, $post->post_title );
+
+        if ( ! empty( $comment->comment_author ) ) {
+                /* translators: 1: comment author's name */
+                $notify_message = sprintf( __( 'Howdy %s,' ), $comment->comment_author ) . "\r\n\r\n";
+        } else {
+                $notify_message = __( 'Howdy,' ) . "\r\n\r\n";
+        }
+
+        /* translators: 1: post title */
+        $notify_message .= sprintf( __( 'Your comment on the post "%s" has been approved.' ), $post->post_title ) . "\r\n\r\n";
+        /* translators: 1: comment permalink */
+        $notify_message .= sprintf( __( 'View comment: %s' ), get_comment_link( $comment ) ) . "\r\n";
+
+        $comment_approval_notification = array(
+                'subject' => $subject,
+                'message' => $notify_message,
+        );
+
+        /**
+         * Filters the content of the email sent to notify a comment author their comment has been approved.
+         *
+         * Content should be formatted for transmission via wp_mail().
+         *
+         * @since 5.7.0
+         *
+         * @param array $comment_approval_notification {
+         *     Used to build wp_mail().
+         *
+         *     @type string $subject The subject of the email.
+         *     @type string $message The content of the email.
+         * }
+         * @param WP_Comment $comment Comment object.
+         */
+        $comment_approval_notification = apply_filters( 'comment_approval_notification', $comment_approval_notification, $comment );
+
+        $sent = wp_mail(
+                $comment->comment_author_email,
+                wp_specialchars_decode( $comment_approval_notification['subject'] ),
+                $comment_approval_notification['message']
+        );
+
+        // Delete the opt-in now the notification has been sent.
+        delete_comment_meta( $comment->comment_ID, '_wp_comment_author_notification_optin' );
+
+        return $sent;
+}
+
 /**
  * Sets the status of a comment.
  *

src/wp-includes/default-filters.php

@@ -463 +463 @@
 add_action( 'after_password_reset', 'wp_password_change_notification' );
 add_action( 'register_new_user', 'wp_send_new_user_notifications' );
 add_action( 'edit_user_created_user', 'wp_send_new_user_notifications', 10, 2 );
+add_action( 'comment_unapproved_to_approved', 'wp_new_comment_notify_comment_author' );
 
 // REST API actions.
 add_action( 'init', 'rest_api_init' );

tests/phpunit/tests/comment.php

@@ -554 +554 @@
                 return $notify_message;
         }
 
+        /**
+         * @ticket 33717
+         */
+        public function test_wp_new_comment_notify_comment_author_once_only() {
+                $c = self::factory()->comment->create(
+                        array(
+                                'comment_post_ID'      => self::$post_id,
+                                'comment_approved'     => '0',
+                                'comment_author_email' => 'foo@bar.mail',
+                        )
+                );
+
+                // The user subscribed to receive an email once comment is approved.
+                update_comment_meta( $c, '_wp_comment_author_notification_optin', true );
+
+                // For the purpose of the test we are removing this hook to directly use the function to notify the comment author.
+                remove_action( 'comment_unapproved_to_approved', 'wp_new_comment_notify_comment_author' );
+
+                // Approve the comment.
+                wp_set_comment_status( $c, 'approve' );
+
+                $sent = wp_new_comment_notify_comment_author( $c );
+                $this->assertTrue( $sent );
+
+                $resent = wp_new_comment_notify_comment_author( $c );
+                $this->assertFalse( $resent );
+        }
+
+        /**
+         * @ticket 33717
+         */
+        public function test_wp_new_comment_notify_comment_author_has_not_optin() {
+                $c = self::factory()->comment->create(
+                        array(
+                                'comment_post_ID'      => self::$post_id,
+                                'comment_approved'     => '0',
+                                'comment_author_email' => 'bat@man.mail',
+                        )
+                );
+
+                // For the purpose of the test we are removing this hook to directly use the function to notify the comment author.
+                remove_action( 'comment_unapproved_to_approved', 'wp_new_comment_notify_comment_author' );
+
+                // Approve the comment.
+                wp_set_comment_status( $c, 'approve' );
+
+                $sent = wp_new_comment_notify_comment_author( $c );
+
+                // The user hasn't subscribed to receive an email, no email should be sent.
+                $this->assertFalse( $sent );
+        }
+
         /**
          * @ticket 12431
          */