Widget: Don't throw errors for invalid method calls (wait till 1.9 to…

… add this back). Reverts fix for #5972 - Widget: Throw error for non-existent method calls.

ui/jquery.ui.widget.js

@@ -96,15 +96,19 @@ $.widget.bridge = function( name, object ) {
 
 		if ( isMethodCall ) {
 			this.each(function() {
-				var instance = $.data( this, name );
-				if ( !instance ) {
-					throw "cannot call methods on " + name + " prior to initialization; " +
-						"attempted to call method '" + options + "'";
-				}
-				if ( !$.isFunction( instance[options] ) ) {
-					throw "no such method '" + options + "' for " + name + " widget instance";
-				}
-				var methodValue = instance[ options ].apply( instance, args );
+				var instance = $.data( this, name ),
+					methodValue = instance && $.isFunction( instance[options] ) ?
+						instance[ options ].apply( instance, args ) :
+						instance;
+				// TODO: add this back in 1.9 and use $.error() (see #5972)
+//				if ( !instance ) {
+//					throw "cannot call methods on " + name + " prior to initialization; " +
+//						"attempted to call method '" + options + "'";
+//				}
+//				if ( !$.isFunction( instance[options] ) ) {
+//					throw "no such method '" + options + "' for " + name + " widget instance";
+//				}
+//				var methodValue = instance[ options ].apply( instance, args );
 				if ( methodValue !== instance && methodValue !== undefined ) {
 					returnValue = methodValue;
 					return false;