REST API: Add error handling for fetch error in `buildModelGetter` of wp-api.js.

When a call to a model getter method fails, reject the returned deferred object. Enables better handling of fetch errors.

Props westonruter, adamsilverstein.
Fixes #39314.

Built from https://develop.svn.wordpress.org/trunk@39680


git-svn-id: http://core.svn.wordpress.org/trunk@39620 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/js/wp-api.js

@@ -321,12 +321,17 @@
 				// Create the new getModel model.
 				getModel = new wp.api.models[ modelName ]( attributes );
 
-				// If we didn’t have an embedded getModel, fetch the getModel data.
 				if ( ! getModel.get( embedCheckField ) ) {
-					getModel.fetch( { success: function( getModel ) {
+					getModel.fetch( {
+						success: function( getModel ) {
 							deferred.resolve( getModel );
-					} } );
+						},
+						error: function( getModel, response ) {
+							deferred.reject( response );
+						}
+					} );
 				} else {
+					// Resolve with the embedded model.
 					deferred.resolve( getModel );
 				}
 
@@ -392,12 +397,17 @@
 
 				// If we didn’t have embedded getObjects, fetch the getObjects data.
 				if ( _.isUndefined( getObjects.models[0] ) ) {
-					getObjects.fetch( { success: function( getObjects ) {
+					getObjects.fetch( {
+						success: function( getObjects ) {
 
 							// Add a helper 'parent_post' attribute onto the model.
 							setHelperParentPost( getObjects, postId );
 							deferred.resolve( getObjects );
-					} } );
+						},
+						error: function( getModel, response ) {
+							deferred.reject( response );
+						}
+					} );
 				} else {
 
 					// Add a helper 'parent_post' attribute onto the model.

wp-includes/version.php

@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.8-alpha-39678';
+$wp_version = '4.8-alpha-39680';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.