feat(typeahead): add noResults indicator binding

src/typeahead/test/typeahead.spec.js

@@ -384,6 +384,40 @@ describe('typeahead tests', function () {
       expect($scope.result).toEqual('AL');
       expect(inputEl.val()).toEqual('AL');
     });
+
+    it('should bind no results indicator as true when no matches returned', inject(function ($timeout) {
+
+      $scope.isNoResults = false;
+      $scope.loadMatches = function (viewValue) {
+        return $timeout(function () {
+          return [];
+        }, 1000);
+      };
+
+      var element = prepareInputEl('<div><input ng-model="result" typeahead="item for item in loadMatches()" typeahead-no-results="isNoResults"></div>');
+      changeInputValueTo(element, 'foo');
+
+      expect($scope.isNoResults).toBeFalsy();
+      $timeout.flush();
+      expect($scope.isNoResults).toBeTruthy();
+    }));
+
+    it('should bind no results indicator as false when matches are returned', inject(function ($timeout) {
+
+      $scope.isNoResults = false;
+      $scope.loadMatches = function (viewValue) {
+        return $timeout(function () {
+          return [viewValue];
+        }, 1000);
+      };
+
+      var element = prepareInputEl('<div><input ng-model="result" typeahead="item for item in loadMatches()" typeahead-no-results="isNoResults"></div>');
+      changeInputValueTo(element, 'foo');
+
+      expect($scope.isNoResults).toBeFalsy();
+      $timeout.flush();
+      expect($scope.isNoResults).toBeFalsy();
+    }));
   });
 
   describe('pop-up interaction', function () {

src/typeahead/typeahead.js

@@ -55,6 +55,9 @@ angular.module('ui.bootstrap.typeahead', ['ui.bootstrap.position', 'ui.bootstrap
       //a callback executed when a match is selected
       var onSelectCallback = $parse(attrs.typeaheadOnSelect);
 
+      //binding to a variable that indicates if there were no results after the query is completed
+      var isNoResultsSetter = $parse(attrs.typeaheadNoResults).assign || angular.noop;
+
       var inputFormatter = attrs.typeaheadInputFormatter ? $parse(attrs.typeaheadInputFormatter) : undefined;
 
       var appendToBody =  attrs.typeaheadAppendToBody ? originalScope.$eval(attrs.typeaheadAppendToBody) : false;
@@ -123,14 +126,15 @@ angular.module('ui.bootstrap.typeahead', ['ui.bootstrap.position', 'ui.bootstrap
 
         var locals = {$viewValue: inputValue};
         isLoadingSetter(originalScope, true);
+		isNoResultsSetter(originalScope, false);
         $q.when(parserResult.source(originalScope, locals)).then(function(matches) {
 
           //it might happen that several async queries were in progress if a user were typing fast
           //but we are interested only in responses that correspond to the current view value
           var onCurrentRequest = (inputValue === modelCtrl.$viewValue);
           if (onCurrentRequest && hasFocus) {
             if (matches.length > 0) {
-
+              isNoResultsSetter(originalScope, false);
               scope.activeIdx = 0;
               scope.matches.length = 0;
 
@@ -154,6 +158,7 @@ angular.module('ui.bootstrap.typeahead', ['ui.bootstrap.position', 'ui.bootstrap
               element.attr('aria-expanded', true);
             } else {
               resetMatches();
+              isNoResultsSetter(originalScope, true);
             }
           }
           if (onCurrentRequest) {
@@ -162,6 +167,7 @@ angular.module('ui.bootstrap.typeahead', ['ui.bootstrap.position', 'ui.bootstrap
         }, function(){
           resetMatches();
           isLoadingSetter(originalScope, false);
+          isNoResultsSetter(originalScope, true);
         });
       };