AngularJS 实现 双击排序

 <th class="col-md-3"><a href="" ng-click="desc(‘2‘,la=!la)">单价</a></th>
 <th class="col-md-3"><a href="" ng-click="desc(‘3‘,la=!la)">销售金额</a></th>
 <th class="col-md-1"><a href="" ng-click="desc(‘4‘,la=!la)">销售数量</a></th>

 $scope.desc= function (fla,bol) {
            if(fla=="4"){
                if(bol==false){
                 
                    $scope.foodsale =$scope.foodsale.sort(function ( x,y )
                    {
                        return y.totalnum - x.totalnum;
                    })
                }else{
                    console.log("bbb")
                    $scope.foodsale =$scope.foodsale.sort(function ( x,y )
                    {
                        return x.totalnum - y.totalnum;
                    })
                }
            }else if(fla=="3"){//totalmoney
                if(bol==false){
                    $scope.foodsale =$scope.foodsale.sort(function ( x,y )
                    {
                        return y.totalmoney - x.totalmoney;
                    })
                }else{
                    $scope.foodsale =$scope.foodsale.sort(function ( x,y )
                        {
                            return x.totalmoney - y.totalmoney;
                        }
                    )
                }
            }else if(fla=="2"){//price
                if(bol==false){
                    $scope.foodsale =$scope.foodsale.sort(function ( x,y )
                    {
                        return y.price - x.price;
                    })
                }else{
                    $scope.foodsale =$scope.foodsale.sort(function ( x,y )
                        {
                            return x.price - y.price;
                        }
                    )
                }
            }