Angular 承诺超时失败

Question

我希望我的承诺在 300 毫秒内无法 return 结果时失败，如果失败，我希望调用另一个承诺，该承诺将执行执行时间更短的默认函数。

到目前为止我尝试过的 -

    $timeout(function(){
      GetAirMsg.get({mDate: $filter('date')($scope.realdateFrom,'ddMMyy'),
                mDateO: $filter('date')($scope.realdateFrom,'yyyyMMdd'),
                mDateD: $filter('date')($scope.realdateFrom,'dd-MMM-yyyy'),
                acode: $filter('uppercase')($scope.air),
                offset: offsetInt}).$promise.then(function(result){
                /* result evaluation */    
            });
      },300).then(function(data){

         console.log('Timed out! sorry!');
         /*execute another promise with shorter execution time */
         console.log('data : '+data);

      },function(error){

        //console.log('Timed out! sorry!');

    });

服务是 -

angular.module('example').factory('GetAirMsg',['$resource',function($resource){
return $resource(serverBaseUrl + '/getAirMsg/:mDate/:mDateO/:mDateD/:acode/:offset', 
        {mDate: '@mDate',mDateO: '@mDateO',mDateD: '@mDateD',acode: '@acode',offset: '@offset'}, {
            get: {method: 'GET', isArray: false}
        });
}])

服务 GetAirMsg 执行一个查询，该查询为几个值占用了大量时间，该查询目前已尽可能优化。因此，我希望可以使用 return 仅提供基本信息的后备方案。

现在面临的问题 - 控制台总是显示 '时间到！对不起！数据：未定义'。对于在该时间范围内没有 return 值的案例，请求将保持待处理状态。

Answer 1

您可以使用 $resource 的 timeout 设置。查看示例用法 here.

作为您的代码示例；

服务：

angular.module('example').factory('GetAirMsg',['$resource',function($resource){
return $resource(serverBaseUrl + '/getAirMsg/:mDate/:mDateO/:mDateD/:acode/:offset', 
        {mDate: '@mDate',mDateO: '@mDateO',mDateD: '@mDateD',acode: '@acode',offset: '@offset'}, {
            get: {method: 'GET', isArray: false, timeout: 300}
        });
}])

控制器：

GetAirMsg.get({mDate: $filter('date')($scope.realdateFrom,'ddMMyy'),
        mDateO: $filter('date')($scope.realdateFrom,'yyyyMMdd'),
        mDateD: $filter('date')($scope.realdateFrom,'dd-MMM-yyyy'),
        acode: $filter('uppercase')($scope.air),
        offset: offsetInt}).$promise
    .then(function(result){
        /* result evaluation */    
    })
    .catch(function() {
        console.log("error!");
    });

Answer 2

显示该控制台的原因是因为 timeout 函数成功运行并且由于 timeout 没有返回任何数据，data 将是 undefined

试试这个。

控制器代码：

$scope.isFirstCallSuccess = false;

$timeout(function(){
 GetAirMsg.get({
  mDate: $filter('date')($scope.realdateFrom,'ddMMyy'),
  mDateO: $filter('date')($scope.realdateFrom,'yyyyMMdd'),
  mDateD: $filter('date')($scope.realdateFrom,'dd-MMM-yyyy'),
  acode: $filter('uppercase')($scope.air),
  offset: offsetInt})
  .$promise
  .then(function(result){
  /* result evaluation */    
  $scope.isFirstCallSuccess = true; // updating only if call success
 }, ,function(error){
  // API call was failure even before the timeout
 });
},300).then(function(){
 if(!$scope.isFirstCallSuccess){
  //the call was failure. the value is still false
  /*execute another promise with shorter execution time */
  console.log('Timed out! sorry!');
 }

});

编辑：

方法：再创建一个服务来取消承诺。如果在超时结束前未完成，请使用该服务取消

服务：

function cancel( promise ) {
//it will cancel the promise only the promise is still active
  if (promise) {
    promise.reject();
  }
}

控制器：

$scope.gettingAirMsg = GetAirMsg.get({
    mDate: $filter('date')($scope.realdateFrom,'ddMMyy'),
    mDateO: $filter('date')($scope.realdateFrom,'yyyyMMdd'),
    mDateD: $filter('date')($scope.realdateFrom,'dd-MMM-yyyy'),
    acode: $filter('uppercase')($scope.air),
    offset: offsetInt})
    .$promise
    .then(function(result){
        //success
        }, ,function(error){

    });

 $timeout(function(){
   yourService.cancel($scope.gettingAirMsg) 
   //it will cancel the promise only the promise is still active
   // if the promise ends before 300ms the cancel call will not pass active promise
 },300)

Answer 3

显示该控制台的原因是因为 timeout 函数成功运行并且由于 timeout 没有返回任何数据，data 将是 undefined

试试这个。

控制器代码：

$scope.isFirstCallSuccess = false;

$timeout(function(){
  GetAirMsg.get({
      mDate: $filter('date')($scope.realdateFrom,'ddMMyy'),
      mDateO: $filter('date')($scope.realdateFrom,'yyyyMMdd'),
      mDateD: $filter('date')($scope.realdateFrom,'dd-MMM-yyyy'),
      acode: $filter('uppercase')($scope.air),
      offset: offsetInt})
    .$promise
    .then(function(result){
    /* result evaluation */    
    $scope.isFirstCallSuccess = true; // updating only if call success
  },function(error){
    // API call was failure even before the timeout
  });
  },300).then(function(){
  if(!$scope.isFirstCallSuccess){
    //the call was failure. the value is still false
    /*execute another promise with shorter execution time */
    console.log('Timed out! sorry!');
  }

});

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