Improve logic for determining when to do fallback refresh for post field partials

js/customize-post-field-partial.js

@@ -35,8 +35,6 @@
 			api.selectiveRefresh.partialConstructor.deferred.prototype.initialize.call( partial, id, args );
 
 			partial.addInstantPreviews();
-
-			// @todo If singular_only, and this is not the post singular post for this partial, then no refresh!
 		},
 
 		/**
@@ -123,6 +121,41 @@
 			return refreshPromise;
 		},
 
+		/**
+		 * Handle fail to render partial.
+		 *
+		 * {@inheritdoc}
+		 *
+		 * @this {wp.customize.selectiveRefresh.partialConstructor.deferred}
+		 * @returns {void}
+		 */
+		fallback: function postFieldPartialFallback() {
+			var partial = this, dependentSelector;
+
+			/*
+			 * Skip invoking fallback behavior for partials on documents that lack matches for
+			 * the fallback dependent selector. The default fallback dependent selector is
+			 * essentially checking to see if a body_class or post_class exists in the document
+			 * which references the given post. If the dependent selector fails to match any
+			 * elements, then the selector dependency fails and the partial should not be added.
+			 * Note that the dependent selector could have been used as a determiner for whether
+			 * the partial was added in the first place. However, this would have meant that no
+			 * selective refresh requests would have been spawned by the change, and this would
+			 * have meant that any Backbone models for the WP-API would not have had the chance
+			 * to get the rendered updates from the server.
+			 */
+			dependentSelector = partial.params.fallbackDependentSelector;
+			if ( ! dependentSelector ) {
+				dependentSelector = '.hentry.post-%d, body.page-id-%d, body.postid-%d';
+			}
+			dependentSelector = dependentSelector.replace( /%d/g, String( partial.params.post_id ) );
+			if ( 0 === $( dependentSelector ).length ) {
+				return;
+			}
+
+			api.selectiveRefresh.partialConstructor.deferred.prototype.fallback.call( partial );
+		},
+
 		/**
 		 * @inheritdoc
 		 */

js/customize-preview-featured-image.js

@@ -7,8 +7,11 @@ var CustomizePreviewFeaturedImage = (function( api, $ ) {
 
 	var component = {
 		data: {
-			partialSelectorAttribute: '',
-			partialContainerInclusive: true
+			partialArgs: {
+				selector: '',
+				containerInclusive: true,
+				fallbackDependentSelector: ''
+			}
 		}
 	};
 
@@ -56,6 +59,37 @@ var CustomizePreviewFeaturedImage = (function( api, $ ) {
 	 */
 	component.FeaturedImagePartial = api.selectiveRefresh.partialConstructor.deferred.extend({
 
+		idPattern: /^postmeta\[(.+?)]\[(\d+)]\[_thumbnail_id]$/,
+
+		/**
+		 * Initialize.
+		 *
+		 * @param {string} id          Partial ID.
+		 * @param {object} args        Args.
+		 * @param {object} args.params Params.
+		 * @returns {void}
+		 */
+		initialize: function( id, args ) {
+			var partial = this, matches, postId, postType, params;
+			matches = id.match( partial.idPattern );
+			postType = matches[1];
+			postId = parseInt( matches[2], 10 );
+			params = _.extend(
+				{
+					post_id: postId,
+					post_type: postType,
+					selector: component.data.partialArgs.selector.replace( /%d/g, String( postId ) ),
+					settings: [ id ],
+					primarySetting: id,
+					containerInclusive: component.data.partialArgs.containerInclusive,
+					fallbackDependentSelector: component.data.partialArgs.fallbackDependentSelector
+				},
+				args ? args.params || {} : {}
+			);
+
+			api.selectiveRefresh.partialConstructor.deferred.prototype.initialize.call( partial, id, { params: params } );
+		},
+
 		/**
 		 * Force fallback (full page refresh) behavior when the featured image is removed.
 		 *
@@ -93,6 +127,27 @@ var CustomizePreviewFeaturedImage = (function( api, $ ) {
 			} else {
 				return api.selectiveRefresh.Partial.prototype.renderContent.call( partial, placement );
 			}
+		},
+
+		/**
+		 * Handle fail to render partial.
+		 *
+		 * Skip performing fallback behavior if post does not appear on the current template.
+		 *
+		 * {@inheritdoc}
+		 *
+		 * @this {wp.customize.selectiveRefresh.partialConstructor.deferred}
+		 * @returns {void}
+		 */
+		fallback: function postFieldPartialFallback() {
+			var partial = this, dependentSelector;
+
+			dependentSelector = partial.params.fallbackDependentSelector.replace( /%d/g, String( partial.params.post_id ) );
+			if ( 0 === $( dependentSelector ).length ) {
+				return;
+			}
+
+			api.selectiveRefresh.partialConstructor.deferred.prototype.fallback.call( partial );
 		}
 	});
 
@@ -103,22 +158,18 @@ var CustomizePreviewFeaturedImage = (function( api, $ ) {
 	 * @returns {component.FeaturedImagePartial|null} New or existing featured image partial, or null if not relevant setting.
 	 */
 	component.ensurePartialForSetting = function ensurePartialForSetting( setting ) {
-		var ensuredPartial, partialId, postId, matches = setting.id.match( /^postmeta\[.+?]\[(\d+)]\[_thumbnail_id]$/ );
-		if ( ! matches ) {
+		var ensuredPartial, partialId;
+		if ( ! component.FeaturedImagePartial.prototype.idPattern.test( setting.id ) ) {
 			return null;
 		}
 		partialId = setting.id;
-		postId = parseInt( matches[1], 10 );
 		ensuredPartial = api.selectiveRefresh.partial( partialId );
 		if ( ensuredPartial ) {
 			return ensuredPartial;
 		}
 		ensuredPartial = new component.FeaturedImagePartial( partialId, {
 			params: {
-				selector: '[' + component.data.partialSelectorAttribute + '=' + String( postId ) + ']',
-				settings: [ setting.id ],
-				primarySetting: setting.id,
-				containerInclusive: component.data.partialContainerInclusive
+				settings: [ setting.id ]
 			}
 		} );
 		api.selectiveRefresh.partial.add( partialId, ensuredPartial );

js/customize-preview-posts.js

@@ -36,7 +36,7 @@
 
 		// Add the partials.
 		_.each( api.previewPosts.partialSchema( setting.id ), function( schema ) {
-			var partial, addPartial, matches, baseSelector;
+			var partial, matches, postId, postType, selectorBases;
 
 			matches = schema.id.match( idPattern );
 			if ( ! matches ) {
@@ -46,25 +46,28 @@
 			if ( api.selectiveRefresh.partial.has( schema.id ) ) {
 				return;
 			}
+			postType = matches[1];
+			postId = parseInt( matches[2], 10 );
 
 			if ( schema.params.selector ) {
-				if ( ! schema.params.bodySelector ) {
-					baseSelector = '.hentry.post-' + String( parseInt( matches[2], 10 ) ) + '.type-' + matches[1];
+
+				selectorBases = [
+					'.hentry.post-' + String( postId )
+				];
+				if ( 'page' === postType ) {
+					selectorBases.push( 'body.page.page-id-' + String( postId ) );
 				} else {
-					baseSelector = '.postid-' + String( parseInt( matches[2], 10 ) ) + '.single-' + matches[1];
+					selectorBases.push( 'body.postid-' + String( postId ) );
 				}
-				schema.params.selector = baseSelector + ' ' + schema.params.selector;
-
-				addPartial =
-					! schema.params.singularOnly && ! schema.params.archiveOnly ||
-					schema.params.singularOnly && api.previewPosts.data.isSingular ||
-					schema.params.archiveOnly && ! api.previewPosts.data.isSingular;
+				schema.params.selector = _.map( selectorBases, function( selectorBase ) {
+					var selector = selectorBase + ' ' + schema.params.selector;
+					selector = selector.replace( /%d/g, String( postId ) );
+					return selector;
+				} ).join( ', ' );
 
-				if ( addPartial ) {
-					partial = new api.selectiveRefresh.partialConstructor.post_field( schema.id, { params: schema.params } );
-					api.selectiveRefresh.partial.add( partial.id, partial );
-					addedPartials.push( partial );
-				}
+				partial = new api.selectiveRefresh.partialConstructor.post_field( schema.id, { params: schema.params } );
+				api.selectiveRefresh.partial.add( partial.id, partial );
+				addedPartials.push( partial );
 			} else {
 				partial = new api.selectiveRefresh.partialConstructor.post_field( schema.id, { params: schema.params } );
 
@@ -79,7 +82,7 @@
 				partial.refresh = function refreshWithoutSelector() {
 					var deferred = $.Deferred();
 					if ( this.params.fallbackRefresh ) {
-						api.selectiveRefresh.requestFullRefresh();
+						api.selectiveRefresh.requestFullRefresh(); // @todo Do partial.fallback()?
 						deferred.resolve();
 					} else {
 						deferred.reject();
@@ -209,7 +212,7 @@
 			} );
 		};
 
-		wp.customize.selectiveRefresh.bind( 'render-partials-response', api.previewPosts.handleRenderPartialsResponse );
+		api.selectiveRefresh.bind( 'render-partials-response', api.previewPosts.handleRenderPartialsResponse );
 	};
 
 	/**

php/class-wp-customize-featured-image-controller.php

@@ -25,6 +25,13 @@ class WP_Customize_Featured_Image_Controller extends WP_Customize_Postmeta_Contr
 	 */
 	const SELECTED_ATTRIBUTE = 'data-customize-featured-image-partial';
 
+	/**
+	 * Selector for finding featured images.
+	 *
+	 * @var string
+	 */
+	const SELECTOR = '[data-customize-featured-image-partial="%d"]';
+
 	/**
 	 * The container_inclusive param for the partials.
 	 *
@@ -117,9 +124,14 @@ public function enqueue_customize_pane_scripts() {
 	public function enqueue_customize_preview_scripts() {
 		$handle = 'customize-preview-featured-image';
 		wp_enqueue_script( $handle );
+
+		// @todo These arguments should be configurable for featured image partials just as they are for post field partials.
 		$exports = array(
-			'partialSelectorAttribute' => self::SELECTED_ATTRIBUTE,
-			'partialContainerInclusive' => self::PARTIAL_CONTAINER_INCLUSIVE,
+			'partialArgs' => array(
+				'selector' => self::SELECTOR,
+				'fallbackDependentSelector' => '.hentry.post-%d, body.page-id-%d, body.postid-%d',
+				'containerInclusive' => self::PARTIAL_CONTAINER_INCLUSIVE,
+			),
 		);
 		wp_add_inline_script( $handle, sprintf( 'CustomizePreviewFeaturedImage.init( %s )', wp_json_encode( $exports ) ) );
 	}
@@ -281,7 +293,7 @@ public function filter_customize_dynamic_partial_args( $partial_args, $partial_i
 			$partial_args['settings'] = array( $setting_id );
 			$partial_args['primary_setting'] = $setting_id;
 			$partial_args['type'] = 'featured_image';
-			$partial_args['selector'] = '[' . self::SELECTED_ATTRIBUTE . '=' . $matches['post_id'] . ']';
+			$partial_args['selector'] = sprintf( self::SELECTOR, $matches['post_id'] );
 			$partial_args['container_inclusive'] = self::PARTIAL_CONTAINER_INCLUSIVE;
 		}
 		return $partial_args;

php/class-wp-customize-posts-preview.php

@@ -91,7 +91,6 @@ public function customize_preview_init() {
 		add_action( 'parse_query', array( $this, 'ensure_page_for_posts_preview' ), 5 );
 		add_filter( 'customize_dynamic_partial_args', array( $this, 'filter_customize_dynamic_partial_args' ), 10, 2 );
 		add_filter( 'customize_dynamic_partial_class', array( $this, 'filter_customize_dynamic_partial_class' ), 10, 3 );
-		add_filter( 'customize_posts_partial_schema', array( $this, 'filter_customize_posts_partial_schema' ) );
 		add_filter( 'the_posts', array( $this, 'filter_the_posts_to_tally_previewed_posts' ), 1000 );
 		add_filter( 'the_posts', array( $this, 'filter_the_posts_to_tally_orderby_keys' ), 10, 2 );
 		add_action( 'wp_footer', array( $this, 'export_preview_data' ), 10 );
@@ -1222,20 +1221,6 @@ function filter_customize_dynamic_partial_class( $partial_class, $partial_id, $p
 		return $partial_class;
 	}
 
-	/**
-	 * Prevent fallback_refresh for select post fields.
-	 *
-	 * @todo There should be some more sophisticated logic for determining whether fallback_refresh is done.
-	 *
-	 * @param array $schema Schema.
-	 * @return array Schema.
-	 */
-	function filter_customize_posts_partial_schema( $schema ) {
-		$schema['post_title']['fallback_refresh'] = false;
-		$schema['post_excerpt']['fallback_refresh'] = false;
-		return $schema;
-	}
-
 	/**
 	 * Filters get_edit_post_link to short-circuits if post cannot be edited in Customizer.
 	 *
@@ -1321,22 +1306,19 @@ public function get_post_field_partial_schema( $field_id = '' ) {
 			),
 			'post_excerpt' => array(
 				'selector' => '.entry-summary',
+				'fallback_refresh' => true,
 			),
 			'comment_status[comments-area]' => array(
 				'selector' => '.comments-area',
-				'body_selector' => true,
-				'singular_only' => true,
 				'container_inclusive' => true,
 			),
 			'comment_status[comments-link]' => array(
 				'selector' => '.comments-link',
-				'archive_only' => true,
+				'fallback_dependent_selector' => 'body.archive', // Only do fallback when on archives.
 				'container_inclusive' => true,
 			),
 			'ping_status' => array(
 				'selector' => '.comments-area',
-				'body_selector' => true,
-				'singular_only' => true,
 				'container_inclusive' => true,
 			),
 			'post_author[byline]' => array(
@@ -1359,6 +1341,15 @@ public function get_post_field_partial_schema( $field_id = '' ) {
 		 */
 		$schema = apply_filters( 'customize_posts_partial_schema', $schema );
 
+		$deprecated_keys = array( 'body_selector', 'archive_only', 'singular_only' );
+		foreach ( $schema as $_field_id => $_partial_args ) {
+			foreach ( $deprecated_keys as $deprecated_key ) {
+				if ( array_key_exists( $deprecated_key, $_partial_args ) ) {
+					_deprecated_argument( __FUNCTION__, '0.8.5', sprintf( __( 'The %s param has been removed from the partial schema. Consider fallback_dependent_selector if needed.', 'customize-posts' ), $deprecated_key ) );
+				}
+			}
+		}
+
 		// Return specific schema based on the field_id & placement.
 		if ( ! empty( $field_id ) ) {
 			if ( isset( $schema[ $field_id ] ) ) {

php/theme-support/class-customize-posts-twenty-eleven-support.php

@@ -43,7 +43,7 @@ public function filter_partial_schema( $schema ) {
 
 		$schema['post_author[biography]'] = array(
 			'selector' => '#author-info',
-			'singular_only' => true,
+			'fallback_dependent_selector' => 'body.singular',
 			'container_inclusive' => true,
 			'render_callback' => array( $this, 'biography_render_callback' ),
 		);

php/theme-support/class-customize-posts-twenty-fifteen-support.php

@@ -41,7 +41,7 @@ public function add_support() {
 	public function filter_partial_schema( $schema ) {
 		$schema['post_author[biography]'] = array(
 			'selector' => '.author-info',
-			'singular_only' => true,
+			'fallback_dependent_selector' => 'body.singular',
 			'container_inclusive' => true,
 			'render_callback' => array( $this, 'biography_render_callback' ),
 		);