Merge pull request #341 from 10up/fix/86v2

fix/86: Display starting vertices whenever a redirect cycle/loop is present
10up · Aug 29, 2023 · 92b575e · 92b575e
2 parents 563be0b + cc11274
commit 92b575e
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Showing 2 changed files with 58 additions and 20 deletions.
diff --git a/inc/classes/class-srm-loop-detection.php b/inc/classes/class-srm-loop-detection.php
@@ -62,7 +62,10 @@ private static function get_directed_graph() {
 				}
 
 				// Add an edge from the source URL to the destination URL.
-				$graph[ $source_url ][] = $destination_url;
+				$graph[ $source_url ][] = array(
+					'id'          => $redirect['ID'],
+					'destination' => $destination_url,
+				);
 			}
 		}
 
@@ -78,27 +81,25 @@ private static function get_directed_graph() {
 	 * @param string $vertex       Node in the graph that holds URL of source or destination.
 	 * @param array  $visited      Array of nodes visited during traversal.
 	 * @param array  $current_path Array of paths traversed.
+	 * @param array  $cycle_source Array of starting point of detected cycles.
 	 *
-	 * @return boolean
+	 * @return void
 	 */
-	private static function has_cycle_recursive( $graph, $vertex, &$visited, &$current_path ) {
+	private static function has_cycle_recursive( $graph, $vertex, &$visited, &$current_path, &$cycle_source ) {
 		$visited[ $vertex ]      = true;
 		$current_path[ $vertex ] = true;
 
 		if ( isset( $graph[ $vertex ] ) ) {
 			foreach ( $graph[ $vertex ] as $neighbor ) {
-				if ( ! isset( $visited[ $neighbor ] ) ) {
-					if ( self::has_cycle_recursive( $graph, $neighbor, $visited, $current_path ) ) {
-						return true;
-					}
-				} elseif ( isset( $current_path[ $neighbor ] ) ) {
-					return true;
+				if ( ! isset( $visited[ $neighbor['destination'] ] ) ) {
+					self::has_cycle_recursive( $graph, $neighbor['destination'], $visited, $current_path, $cycle_source );
+				} elseif ( isset( $current_path[ $neighbor['destination'] ] ) ) {
+					$cycle_source[] = $neighbor;
 				}
 			}
 		}
 
 		unset( $current_path[ $vertex ] );
-		return false;
 	}
 
 	/**
@@ -110,15 +111,35 @@ public static function detect_redirect_loops() {
 		$graph        = self::get_directed_graph();
 		$visited      = array();
 		$current_path = array();
+		$cycle_source = array();
 
 		foreach ( $graph as $vertex => $destinations ) {
 			if ( ! isset( $visited[ $vertex ] ) ) {
-				if ( self::has_cycle_recursive( $graph, $vertex, $visited, $current_path ) ) {
-					return true;
+				if ( self::has_cycle_recursive( $graph, $vertex, $visited, $current_path, $cycle_source ) ) {
+					return $cycle_source;
 				}
 			}
 		}
 
-		return false;
+		return $cycle_source;
+	}
+
+	/**
+	 * Returns an array of "Redirect From" values that are the starting vertices of redirect loops.
+	 *
+	 * @param array $cycle_source Array of redirect loops.
+	 *
+	 * @return array
+	 */
+	public static function get_cycle_source( $cycle_source = array() ) {
+		return array_map(
+			function( $source ) {
+				return array(
+					'path' => wp_parse_url( esc_url( $source['destination'] ), PHP_URL_PATH ),
+					'id'   => $source['id'],
+				);
+			},
+			$cycle_source
+		);
 	}
 }
diff --git a/inc/classes/class-srm-post-type.php b/inc/classes/class-srm-post-type.php
@@ -231,14 +231,31 @@ public function action_redirect_chain_alert() {
 		if ( $this->is_plugin_page() ) {
 
 			/**
-			 * check_for_possible_redirect_loops() runs in best case Theta(n^2) so if you have 100 redirects, this method
-			 * will be running slow. Let's disable it by default.
+			 * Hook to toggle check for redirect loop.
+			 *
+			 * @param boolean $enable_loop_detection Detects redirect loop if true.
 			 */
-			if ( apply_filters( 'srm_check_for_possible_redirect_loops', false ) ) {
-				if ( SRM_Loop_Detection::detect_redirect_loops() ) {
+			if ( apply_filters( 'srm_check_for_possible_redirect_loops', true ) ) {
+				$cycle_source = SRM_Loop_Detection::detect_redirect_loops();
+				$paths        = SRM_Loop_Detection::get_cycle_source( $cycle_source );
+
+				if ( ! empty( $cycle_source ) ) {
 					?>
 					<div class="notice notice-warning">
-						<p><?php esc_html_e( 'Safe Redirect Manager Warning: Possible redirect loops and/or chains have been created.', 'safe-redirect-manager' ); ?></p>
+						<p><?php esc_html_e( 'Safe Redirect Manager Warning: The following redirects with the "Redirect To" value have created redirect chain/loops.', 'safe-redirect-manager' ); ?></p>
+						<ul style="list-style: inside;">
+							<?php foreach ( $paths as $path ) : ?>
+								<li>
+								<?php
+									printf(
+										'<a href="%s">%s</a>',
+										esc_url( get_edit_post_link( esc_html( $path['id'] ) ) ),
+										esc_html( $path['path'] )
+									);
+								?>
+								</li>
+							<?php endforeach; ?>
+						</ul style>
 					</div>
 					<?php
 				}
@@ -710,8 +727,8 @@ public function load_resources() {
 				'redirectjs',
 				'redirectValidation',
 				array(
-					'urlError' => __( 'There are some issues validating the URL. Please try again.', 'safe-redirect-manager' ),
-					'fail'     => __( 'There is an existing redirect with the same Redirect From URL. You may <a href="%s">Edit</a> the redirect or try other `from` URL.', 'safe-redirect-manager' ),
+					'urlError'   => __( 'There are some issues validating the URL. Please try again.', 'safe-redirect-manager' ),
+					'fail'       => __( 'There is an existing redirect with the same Redirect From URL. You may <a href="%s">Edit</a> the redirect or try other `from` URL.', 'safe-redirect-manager' ),
 					'ajax_url'   => admin_url( 'admin-ajax.php' ),
 					'ajax_nonce' => wp_create_nonce( 'srm_autocomplete_nonce' ),
 				)