Angularjs：爲什麼$ watch先於其他函數執行

Question

形成我所知道的函數應該從上到下。但在這段代碼中，手錶首先會比getOrders函數執行。任何人都有讓getOrders函數首先執行的解決方案？

$scope.getOrders=function() { 
     OrderService.getOrders(1) 
     .success(function (ords) { 
      if (angular.isArray(ords)) { 
       $scope.Orders = ords; 
       console.log("testing2"); 
       console.log("testing 3"+$scope.Orders); 
      } else { 
       $scope.Orders = [ords]; 
       console.log("testing"); 
      } 

      $scope.dateT = true; 
      $scope.StatusEnum = { 10: "Pending", 20: "Processing", 30: "Ready to Shipping", 40: "Cancelled" }; 

     }).error(function (error) { 
      $scope.status = 'Unable to load customer data: ' + error.message; 
      console.log($scope.status); 
     }); 
    } 
//Here edited, I got add in but still cant 
$scope.getOrders(); 
$scope.$watch('currentPage + numPerPage', function() { 

      var begin = (($scope.currentPage - 1) * $scope.numPerPage), end = begin + $scope.numPerPage; 
      //$scope.filteredTodos = $scope.Orders.slice(begin, end); 
      console.log("testing" + $scope.Orders); 
     },1); 

但我在控制檯看到的結果是這樣的

Answer 1

您可以比較新的價值與舊值，如果是不同的，只有它被執行，就像這樣：

$scope.$watch('your variable', function(newValue, oldValue){ 
    if(newValue != oldValue){ 
     //execute your code here 
    } 
    }, true); 

Answer 2

您錯誤地記錄它，你testing2和testing 3日誌調用不是從getOrders功能，但從成功回調。此外，您並未記錄$watch函數，但您記錄的是在currentPage + numPerPage表達式中的值更改時執行的回調。 getOrders和$watch函數按照您預期的方式執行，但回調函數不按該順序執行。

如果你想爲一些代碼，當訂單返回，你應該在success回調執行它，這樣來執行：

$scope.getOrders=function() { 
     OrderService.getOrders(1) 
     .success(function (ords) { 
      if (angular.isArray(ords)) { 
       $scope.Orders = ords; 
       console.log("testing2"); 
       console.log("testing 3"+$scope.Orders); 
      } else { 
       $scope.Orders = [ords]; 
       console.log("testing"); 
      } 

      $scope.dateT = true; 
      $scope.StatusEnum = { 10: "Pending", 20: "Processing", 30: "Ready to Shipping", 40: "Cancelled" }; 

      // execute some code here (I'm making it up) 
      $scope.currentPage = ords.currentPage; 
      $scope.numPerPage = ords.numPerPage; 
      // this will also trigger the watch you registered 
      // or you can do what you do in watch callback here 

     }).error(function (error) { 
      $scope.status = 'Unable to load customer data: ' + error.message; 
      console.log($scope.status); 
     }); 
    }; 

Answer 3

THX到@theo關於成功，我只是把$範圍$ watch功能進入成功。然後它工作。

$scope.getOrders=function() { 
      OrderService.getOrders(1) 
      .success(function (ords) { 
       if (angular.isArray(ords)) { 
        $scope.Orders = ords; 
        console.log("testing2"); 
        console.log("testing 3"+$scope.Orders); 
       } else { 
        $scope.Orders = [ords]; 
        console.log("testing"); 
       } 

       $scope.dateT = true; 
       $scope.StatusEnum = { 10: "Pending", 20: "Processing", 30: "Ready to Shipping", 40: "Cancelled" }; 

       //Move the watch inside the success 
       $scope.$watch('currentPage + numPerPage', function() { 
        var begin = (($scope.currentPage - 1) * $scope.numPerPage), end = begin + $scope.numPerPage; 
        $scope.filteredTodos = $scope.Orders.slice(begin, end); 
        console.log("testing" + $scope.Orders); 
       }); 
      }).error(function (error) { 
       $scope.status = 'Unable to load customer data: ' + error.message; 
       console.log($scope.status); 
      }); 
     }