Changeset 48273 for trunk/src/wp-includes/rest-api.php

Timestamp:

07/02/2020 05:55:04 AM (4 years ago)

Author:

TimothyBlynJacobs

Message:

REST API: Link to the REST route for the currently queried resource.

This allows for programatically determining the REST version of the current page. The links also aid human discovery of the REST API in general.

Props dshanske, tfrommen, TimothyBlynJacobs.
Fixes #49116.

File:

• trunk/src/wp-includes/rest-api.php (modified) (4 diffs)

trunk/src/wp-includes/rest-api.php

@@ -235 +235 @@
     // Terms.
     foreach ( get_taxonomies( array( 'show_in_rest' => true ), 'object' ) as $taxonomy ) {
-        $class = ! empty( $taxonomy->rest_controller_class ) ? $taxonomy->rest_controller_class : 'WP_REST_Terms_Controller';
-
-        if ( ! class_exists( $class ) ) {
-            continue;
-        }
-        $controller = new $class( $taxonomy->name );
-        if ( ! is_subclass_of( $controller, 'WP_REST_Controller' ) ) {
+        $controller = $taxonomy->get_rest_controller();
+
+        if ( ! $controller ) {
             continue;
         }
@@ -874 +870 @@
     }
 
-    echo "<link rel='https://api.w.org/' href='" . esc_url( $api_root ) . "' />\n";
+    printf( '<link rel="https://api.w.org/" href="%s" />', esc_url( $api_root ) );
+
+    $resource = rest_get_queried_resource_route();
+
+    if ( $resource ) {
+        printf( '<link rel="alternate" type="application/json" href="%s" />', esc_url( rest_url( $resource ) ) );
+    }
 }
 
@@ -893 +895 @@
     }
 
-    header( 'Link: <' . esc_url_raw( $api_root ) . '>; rel="https://api.w.org/"', false );
+    header( sprintf( 'Link: <%s>; rel="https://api.w.org/"', esc_url_raw( $api_root ) ), false );
+
+    $resource = rest_get_queried_resource_route();
+
+    if ( $resource ) {
+        header( sprintf( 'Link: <%s>; rel="alternate"; type="application/json"', esc_url_raw( rest_url( $resource ) ) ), false );
+    }
 }
 
@@ -1824 +1832 @@
     return $schema;
 }
+
+/**
+ * Gets the REST API route for a post.
+ *
+ * @since 5.5.0
+ *
+ * @param int|WP_Post $post Post ID or post object.
+ * @return string The route path with a leading slash for the given post, or an empty string if there is not a route.
+ */
+function rest_get_route_for_post( $post ) {
+    $post = get_post( $post );
+
+    if ( ! $post instanceof WP_Post ) {
+        return '';
+    }
+
+    $post_type = get_post_type_object( $post->post_type );
+    if ( ! $post_type ) {
+        return '';
+    }
+
+    $controller = $post_type->get_rest_controller();
+    if ( ! $controller ) {
+        return '';
+    }
+
+    $route = '';
+
+    // The only two controllers that we can detect are the Attachments and Posts controllers.
+    if ( in_array( get_class( $controller ), array( 'WP_REST_Attachments_Controller', 'WP_REST_Posts_Controller' ), true ) ) {
+        $namespace = 'wp/v2';
+        $rest_base = ! empty( $post_type->rest_base ) ? $post_type->rest_base : $post_type->name;
+        $route     = sprintf( '/%s/%s/%d', $namespace, $rest_base, $post->ID );
+    }
+
+    /**
+     * Filters the REST API route for a post.
+     *
+     * @since 5.5.0
+     *
+     * @param string  $route The route path.
+     * @param WP_Post $post  The post object.
+     */
+    return apply_filters( 'rest_route_for_post', $route, $post );
+}
+
+/**
+ * Gets the REST API route for a term.
+ *
+ * @since 5.5.0
+ *
+ * @param int|WP_Term $term Term ID or term object.
+ * @return string The route path with a leading slash for the given term, or an empty string if there is not a route.
+ */
+function rest_get_route_for_term( $term ) {
+    $term = get_term( $term );
+
+    if ( ! $term instanceof WP_Term ) {
+        return '';
+    }
+
+    $taxonomy = get_taxonomy( $term->taxonomy );
+    if ( ! $taxonomy ) {
+        return '';
+    }
+
+    $controller = $taxonomy->get_rest_controller();
+    if ( ! $controller ) {
+        return '';
+    }
+
+    $route = '';
+
+    // The only controller that works is the Terms controller.
+    if ( 'WP_REST_Terms_Controller' === get_class( $controller ) ) {
+        $namespace = 'wp/v2';
+        $rest_base = ! empty( $taxonomy->rest_base ) ? $taxonomy->rest_base : $taxonomy->name;
+        $route     = sprintf( '/%s/%s/%d', $namespace, $rest_base, $term->term_id );
+    }
+
+    /**
+     * Filters the REST API route for a term.
+     *
+     * @since 5.5.0
+     *
+     * @param string  $route The route path.
+     * @param WP_Term $term  The term object.
+     */
+    return apply_filters( 'rest_route_for_term', $route, $term );
+}
+
+/**
+ * Gets the REST route for the currently queried object.
+ *
+ * @since 5.5.0
+ *
+ * @return string The REST route of the resource, or an empty string if no resource identified.
+ */
+function rest_get_queried_resource_route() {
+    if ( is_singular() ) {
+        $route = rest_get_route_for_post( get_queried_object() );
+    } elseif ( is_category() || is_tag() || is_tax() ) {
+        $route = rest_get_route_for_term( get_queried_object() );
+    } elseif ( is_author() ) {
+        $route = '/wp/v2/users/' . get_queried_object_id();
+    } else {
+        $route = '';
+    }
+
+    /**
+     * Filters the REST route for the currently queried object.
+     *
+     * @since 5.5.0
+     *
+     * @param string $link The route with a leading slash, or an empty string.
+     */
+    return apply_filters( 'rest_queried_resource_route', $route );
+}