Adding "$stateChangeRejected" event to ui-router.

ui-router-stateChangeRejected.js

(function(){
	"use strict";
	
	/**
	 * Hijacks the ui-router $state.transitionTo() method to capture it's promise.
	 * the promise is added to the $state as $promise (may or may not be needed);
	 * also adds handler for rejection of the $promise.
	 */

	angular
		.module("stm.ui.stateChangeRejected", ['ui.router'])
		.config(stateChangeRejected);

	function stateChangeRejected($provide){
		$provide.decorator("$state", decorateTransitionTo);

		decorateTransitionTo.$inject = ['$delegate', '$rootScope'];
		
		function decorateTransitionTo($delegate, $rootScope){ //$delegate === $state
			var nativeTransitionTo = $delegate.transitionTo; //transfer reference

			$delegate.transitionTo = transitionToWrapper;// replace with wrapper

			return $delegate;

			function transitionToWrapper(){
				var args = [].slice.call(arguments);
				var promise = nativeTransitionTo.apply(this, args);//call original transitionTo, capture promise
				
				promise['catch'](onStateRejection);	//add handler for rejection
				$delegate.$promise = promise;		//add $promise to default $state object

				return promise;

				function onStateRejection(error){
					var toState = $delegate.get(args[0]);
					var toParams = args[1];
					
					$rootScope.$broadcast("$stateChangeRejected", toState, toParams, $delegate.current, $delegate.params, error);
					
					return error;
				}
			}
		}
	}
}());

Thank you @deanapeterson ! It's an informative gist that works on v0.2.18 :)