Add support for allowing a site subset to be native AMP

amp.php

@@ -272,28 +272,55 @@ function amp_correct_query_when_is_front_page( WP_Query $query ) {
 }
 
 /**
- * Whether this is in 'canonical mode.'
+ * Whether this is in 'canonical mode'.
  *
- * Themes can register support for this with `add_theme_support( 'amp' )`.
- * Then, this will change the plugin from 'paired mode,' and it won't use its own templates.
- * Nor output frontend markup like the 'rel' link. If the theme registers support for AMP with:
- * `add_theme_support( 'amp', array( 'template_dir' => 'my-amp-templates' ) )`
- * it will retain 'paired mode.
+ * Themes can register support for this with `add_theme_support( 'amp' )`:
  *
- * @return boolean Whether this is in AMP 'canonical mode'.
+ * add_theme_support( 'amp' );
+ *
+ * This will serve templates in native AMP by default but the user would be able to change the template mode
+ * from native to paired in the admin. To force only native to be available, such as when you are using AMP components
+ * in your theme templates, do:
+ *
+ * add_theme_support( 'amp', array(
+ * 'mode' => 'native',
+ * ) );
+ *
+ * If you want to force AMP to always be served on a given template, use the amp_supportable_templates filter,
+ * for example to always serve the Category template in AMP:
+ *
+ * add_filter( 'amp_supportable_templates', function( $templates ) {
+ * $templates['is_category']['supported'] = true;
+ * return $template;
+ * } );
+ *
+ * Or if you want to prevent AMP from ever being served on the homepage:
+ *
+ * add_filter( 'amp_supportable_templates', function( $templates ) {
+ * $templates['is_front_page']['supported'] = false;
+ * return $template;
+ * } );
+ *
+ * @todo There needs to be a required flag which is the same as forcing all to be supported. This would be the same in the UI as the all_templates_supported flag. Might as well rename all_templates_supported to just required. If required is set to be false, or if any of the supported templates are immutable, then this option should not be available.
+ *
+ * @return boolean Whether this is in AMP 'canonical' mode, that is whether it is native and there is not separate AMP URL current URL.
  */
 function amp_is_canonical() {
- $support = get_theme_support( 'amp' );
- if ( true === $support ) {
- return true;
+ if ( ! current_theme_supports( 'amp' ) ) {
+ return false;
  }
+
+ $mode = 'native';
+ $support = get_theme_support( 'amp' );
  if ( is_array( $support ) ) {
  $args = array_shift( $support );
- if ( empty( $args['template_dir'] ) ) {
- return true;
+ if ( isset( $args['mode'] ) ) {
+ $mode = $args['mode'];
+ } elseif ( ! empty( $args['template_dir'] ) ) {
+ $mode = 'paired'; // If there is a template_dir, then paired mode is implied.
  }
  }
- return false;
+ return 'native' === $mode;
 }
 
 /**
@@ -426,6 +453,7 @@ function _amp_bootstrap_customizer() {
 
 /**
  * Redirects the old AMP URL to the new AMP URL.
+ *
  * If post slug is updated the amp page with old post slug will be redirected to the updated url.
  *
  * @since 0.5

includes/admin/class-amp-post-meta-box.php

@@ -170,16 +170,38 @@ public function render_status( $post ) {
  is_post_type_viewable( $post->post_type )
  &&
  current_user_can( 'edit_post', $post->ID )
- &&
- ! amp_is_canonical()
+ // @todo What if a site does not have non-AMP pages? Formerly this was indicated via amp_is_canonical(). Now we need a flag for whether AMP is exclusive to a theme, in which case all templates and post types must render AMP. In other words, all_templates_supported.
  );
 
  if ( true !== $verify ) {
  return;
  }
 
  $errors = AMP_Post_Type_Support::get_support_errors( $post );
- $status = post_supports_amp( $post ) ? self::ENABLED_STATUS : self::DISABLED_STATUS;
+ $status = empty( $errors ) ? self::ENABLED_STATUS : self::DISABLED_STATUS;
+ $errors = array_diff( $errors, array( 'post-status-disabled' ) ); // Subtract the status which the metabox will allow to be toggled.
+
+ // @todo If ! supported and immutable, don't show the toggle at all?
+ // Handle special case of the static front page or page for posts.
+ if ( current_theme_supports( 'amp' ) ) {
+
+ $query = new WP_Query();
+ if ( 'page' === $post->post_type ) {
+ $query->set( 'page_id', $post->ID );
+ } else {
+ $query->set( 'p', $post->ID );
+ }
+ $query->queried_object = $post;
+ $query->queried_object_id = $post->ID;
+ $query->parse_query_vars();
+
+ $availability = AMP_Theme_Support::get_template_availability( $query );
+ if ( $availability instanceof WP_Error && 0 !== count( array_diff( $availability->get_error_codes(), $errors, array( 'post-status-disabled' ) ) ) ) {
+ $errors[] = 'template-unavailable';
+ $status = self::DISABLED_STATUS;
+ }
+ }
+
  $labels = array(
  'enabled' => __( 'Enabled', 'amp' ),
  'disabled' => __( 'Disabled', 'amp' ),

includes/amp-helper-functions.php

@@ -239,80 +239,62 @@ function amp_add_amphtml_link() {
  * @see AMP_Post_Type_Support::get_support_errors()
  *
  * @param WP_Post $post Post.
- *
  * @return bool Whether the post supports AMP.
  */
 function post_supports_amp( $post ) {
- if ( amp_is_canonical() ) {
- return true;
- }
-
- $errors = AMP_Post_Type_Support::get_support_errors( $post );
-
- // Return false if an error is found.
- if ( ! empty( $errors ) ) {
- return false;
- }
-
- switch ( get_post_meta( $post->ID, AMP_Post_Meta_Box::STATUS_POST_META_KEY, true ) ) {
- case AMP_Post_Meta_Box::ENABLED_STATUS:
- return true;
-
- case AMP_Post_Meta_Box::DISABLED_STATUS:
- return false;
-
- // Disabled by default for custom page templates, page on front and page for posts.
- default:
- $enabled = (
- ! (bool) get_page_template_slug( $post )
- &&
- ! (
- 'page' === $post->post_type
- &&
- 'page' === get_option( 'show_on_front' )
- &&
- in_array( (int) $post->ID, array(
- (int) get_option( 'page_on_front' ),
- (int) get_option( 'page_for_posts' ),
- ), true )
- )
- );
-
- /**
- * Filters whether default AMP status should be enabled or not.
- *
- * @since 0.6
- *
- * @param string $status Status.
- * @param WP_Post $post Post.
- */
- return apply_filters( 'amp_post_status_default_enabled', $enabled, $post );
- }
+ return 0 === count( AMP_Post_Type_Support::get_support_errors( $post ) );
 }
 
 /**
- * Are we currently on an AMP URL?
+ * Determine whether the current response being served as AMP.
  *
- * @since 1.0 This function can be called before the `parse_query` action because the 'amp' query var is specifically and exclusively used when 'amp' theme support is added.
+ * This function cannot be called before the parse_query action because it needs to be able
+ * to determine the queried object is able to be served as AMP.
  *
+ * @see is_header_video_active()
  * @return bool Whether it is the AMP endpoint.
  */
 function is_amp_endpoint() {
+ global $wp_query;
  if ( is_admin() || is_feed() || ( defined( 'REST_REQUEST' ) && REST_REQUEST ) ) {
  return false;
  }
 
- // When 'amp' theme support is (or will be added) then these are the conditions that are key to be checked.
- if ( amp_is_canonical() || isset( $_GET[ amp_get_slug() ] ) ) { // WPCS: CSRF OK.
- return true;
+ $did_parse_query = did_action( 'parse_query' );
+
+ if ( ! $did_parse_query ) {
+ _doing_it_wrong( __FUNCTION__, sprintf( esc_html__( "is_amp_endpoint() was called before the 'parse_query' hook was called. This function will always return 'false' before the 'parse_query' hook is called.", 'amp' ) ), '0.4.2' );
  }
 
- // Condition for non-theme support when /amp/ endpoint is used.
- if ( false !== get_query_var( amp_get_slug(), false ) ) {
- return true;
+ $has_amp_query_var = (
+ isset( $_GET[ amp_get_slug() ] ) // WPCS: CSRF OK.
+ ||
+ false !== get_query_var( amp_get_slug(), false )
+ );
+
+ // When there is no query var and AMP is not canonical/native, then this is definitely not an AMP endpoint.
+ if ( ! $has_amp_query_var && ! amp_is_canonical() ) {
+ return false;
  }
 
- return false;
+ if ( current_theme_supports( 'amp' ) ) {
+ $template_available = true === AMP_Theme_Support::get_template_availability();
+ return amp_is_canonical() ? $template_available : $has_amp_query_var;
+ } else {
+
+ // Check if the queried object supports AMP.
+ if ( is_singular() || ( $wp_query instanceof WP_Query && $wp_query->is_posts_page ) ) {
+ /**
+ * Post.
+ *
+ * @var WP_Post $queried_object
+ */
+ $queried_object = get_queried_object();
+ return post_supports_amp( $queried_object );
+ }
+
+ return false; // Legacy templates only support posts via AMP_Post_Template.
+ }
 }
 
 /**

includes/class-amp-post-type-support.php

@@ -14,9 +14,11 @@ class AMP_Post_Type_Support {
  /**
  * Get post types that plugin supports out of the box (which cannot be disabled).
  *
+ * @deprecated
  * @return string[] Post types.
  */
  public static function get_builtin_supported_post_types() {
+ _deprecated_function( __METHOD__, '1.0' );
  return array_filter( array( 'post' ), 'post_type_exists' );
  }
 
@@ -27,17 +29,12 @@ public static function get_builtin_supported_post_types() {
  * @return string[] Post types eligible for AMP.
  */
  public static function get_eligible_post_types() {
- return array_merge(
- self::get_builtin_supported_post_types(),
- array( 'page' ),
- array_values( get_post_types(
- array(
- 'public' => true,
- '_builtin' => false,
- ),
- 'names'
- ) )
- );
+ return array_values( get_post_types(
+ array(
+ 'public' => true,
+ ),
+ 'names'
+ ) );
  }
 
  /**
@@ -49,10 +46,11 @@ public static function get_eligible_post_types() {
  * @since 0.6
  */
  public static function add_post_type_support() {
- $post_types = array_merge(
- self::get_builtin_supported_post_types(),
- AMP_Options_Manager::get_option( 'supported_post_types', array() )
- );
+ if ( current_theme_supports( 'amp' ) && AMP_Options_Manager::get_option( 'all_templates_supported' ) ) {
+ $post_types = self::get_eligible_post_types();
+ } else {
+ $post_types = AMP_Options_Manager::get_option( 'supported_post_types', array() );
+ }
  foreach ( $post_types as $post_type ) {
  add_post_type_support( $post_type, amp_get_slug() );
  }
@@ -72,8 +70,7 @@ public static function get_support_errors( $post ) {
  }
  $errors = array();
 
- // Because `add_rewrite_endpoint` doesn't let us target specific post_types.
- if ( isset( $post->post_type ) && ! post_type_supports( $post->post_type, amp_get_slug() ) ) {
+ if ( ! post_type_supports( $post->post_type, amp_get_slug() ) ) {
  $errors[] = 'post-type-support';
  }
 
@@ -94,6 +91,48 @@ public static function get_support_errors( $post ) {
  $errors[] = 'skip-post';
  }
 
+ $status = get_post_meta( $post->ID, AMP_Post_Meta_Box::STATUS_POST_META_KEY, true );
+ if ( $status ) {
+ if ( AMP_Post_Meta_Box::DISABLED_STATUS === $status ) {
+ $errors[] = 'post-status-disabled';
+ }
+ } else {
+ /*
+ * Disabled by default for custom page templates, page on front and page for posts, unless 'amp' theme
+ * support is present (in which case AMP_Theme_Support::get_template_availability() determines availability).
+ */
+ $enabled = (
+ current_theme_supports( 'amp' )
+ ||
+ (
+ ! (bool) get_page_template_slug( $post )
+ &&
+ ! (
+ 'page' === $post->post_type
+ &&
+ 'page' === get_option( 'show_on_front' )
+ &&
+ in_array( (int) $post->ID, array(
+ (int) get_option( 'page_on_front' ),
+ (int) get_option( 'page_for_posts' ),
+ ), true )
+ )
+ )
+ );
+
+ /**
+ * Filters whether default AMP status should be enabled or not.
+ *
+ * @since 0.6
+ *
+ * @param string $status Status.
+ * @param WP_Post $post Post.
+ */
+ $enabled = apply_filters( 'amp_post_status_default_enabled', $enabled, $post );
+ if ( ! $enabled ) {
+ $errors[] = 'post-status-disabled';
+ }
+ }
  return $errors;
  }
 }