Changeset 37685 for trunk/src/wp-includes/link-template.php

Timestamp:

06/11/2016 01:30:23 PM (8 years ago)

Author:

ocean90

Message:

Canonical: Introduce wp_get_canonical_url().

wp_get_canonical_url() encapsulates the URL logic of rel_canonical() to provide a consistent way to retrieve the canonical URL for a post.
The new filter get_canonical_url allows to customize the canonical URL.

Props joostdevalk, jipmoors, DrewAPicture, ocean90.
Fixes #36168.

File:

• trunk/src/wp-includes/link-template.php (modified) (2 diffs)

trunk/src/wp-includes/link-template.php

@@ -3540 +3540 @@
 
 /**
+ * Returns the canonical URL for a post.
+ *
+ * When the post is the same as the current requested page the function will handle the
+ * pagination arguments too.
+ *
+ * @since 4.6.0
+ *
+ * @param int|WP_Post $post Optional. Post ID or object. Default is global `$post`.
+ * @return string|false The canonical URL, or false if the post does not exist or has not
+ *                      been published yet.
+ */
+function wp_get_canonical_url( $post = null ) {
+    $post = get_post( $post );
+
+    if ( ! $post ) {
+        return false;
+    }
+
+    if ( 'publish' !== $post->post_status ) {
+        return false;
+    }
+
+    $canonical_url = get_permalink( $post );
+
+    // If a canonical is being generated for the current page, make sure it has pagination if needed.
+    if ( $post->ID === get_queried_object_id() ) {
+        $page = get_query_var( 'page', 0 );
+        if ( $page >= 2 ) {
+            if ( '' == get_option( 'permalink_structure' ) ) {
+                $canonical_url = add_query_arg( 'page', $page, $canonical_url );
+            } else {
+                $canonical_url = trailingslashit( $canonical_url ) . user_trailingslashit( $page, 'single_paged' );
+            }
+        }
+
+        $cpage = get_query_var( 'cpage', 0 );
+        if ( $cpage ) {
+            $canonical_url = get_comments_pagenum_link( $cpage );
+        }
+    }
+
+    /**
+     * Filters the canonical URL for a post.
+     *
+     * @since 4.6.0
+     *
+     * @param string  $string The post's canonical URL.
+     * @param WP_Post $post   Post object.
+     */
+    return apply_filters( 'get_canonical_url', $canonical_url, $post );
+}
+
+/**
  * Outputs rel=canonical for singular queries.
  *
  * @since 2.9.0
+ * @since 4.6.0 Adjusted to use `wp_get_canonical_url()`.
  */
 function rel_canonical() {
@@ -3549 +3603 @@
     }
 
-    if ( ! $id = get_queried_object_id() ) {
+    $id = get_queried_object_id();
+
+    if ( 0 === $id ) {
         return;
     }
 
-    $url = get_permalink( $id );
-
-    $page = get_query_var( 'page' );
-    if ( $page >= 2 ) {
-        if ( '' == get_option( 'permalink_structure' ) ) {
-            $url = add_query_arg( 'page', $page, $url );
-        } else {
-            $url = trailingslashit( $url ) . user_trailingslashit( $page, 'single_paged' );
-        }
-    }
-
-    $cpage = get_query_var( 'cpage' );
-    if ( $cpage ) {
-        $url = get_comments_pagenum_link( $cpage );
-    }
-    echo '<link rel="canonical" href="' . esc_url( $url ) . "\" />\n";
+    $url = wp_get_canonical_url( $id );
+
+    if ( ! empty( $url ) ) {
+        echo '<link rel="canonical" href="' . esc_url( $url ) . '" />' . "\n";
+    }
 }