$on $broadcast 事件不工作

有两个控制器：

       app.controller('comboController',  function ($scope, $http) {
        $http.get("http://InternetShop/php_files/supermarket.php?category=main").
            success(function (data) {
            $scope.categoryes = data;
            console.log($scope.categoryes);
    });
        $scope.SetCategoryName = function(category){
            console.log(category);
          $scope.$broadcast('changeVal', category);
        };
});

        app.controller('tableController', function ($scope, $http) {    
        $scope.currentCombo = "Meat";
            $scope.$on( 'changeVal', function(event, data ) {console.log(data);
            $scope.currentCombo = data;      
    }); 
      GetRequest($scope, $http, $scope.currentCombo);
});

function GetRequest($scope, $http, currentCombo){
    $http.get("http://InternetShop/php_files/supermarket.php?category="+currentCombo).
            success(function (data) {
            $scope.products = data;
            console.log($scope.products);
        });
}

其逻辑是，当您单击下拉列表中的其中一个值时，表格应该更新。但没有任何效果。有人怀疑我在事件中做错了什么。这是视图：

<div ng-controller="comboController">
    <div  class="form-group col-sm-2" >
        <select  class="form-control">
            <optgroup ng-repeat="category in categoryes track by $index"> 
                <option ng-click="SetCategoryName(category)">{{category}}</option>
            </optgroup>
        </select>
    </div>
<div class="col-sm-10" ng-controller="tableController">
    <table class="table table-hover">
        <thead>
            <tr>
                <th>id</th>
                <th>Foto</th>
                <th>Name</th>
                <th>Price</th>
                <th>Description</th>
            </tr>
        </thead>
        <tbody >
            <tr ng-repeat="product in products track by $index">
                <td>{{product.id}}</td>
                <td><img alt="alt" src="img/{{product.img}}"/></td>
                <td>{{product.name}}</td>
                <td>{{product.price}}</td>
                <td>{{product.description}}</td>
            </tr>
        </tbody>
    </table>
</div>
</div>