5 回答

• 6

  Short answer: Yes, you can 在您返回之前解决AngularJS承诺，并且它将按照您的预期运行 .

  从JB Nizet's Plunkr开始，但重构为在最初要求的内容（即函数调用服务）的上下文中工作，并且实际在现场 .

  服务内...

  function getSomething(id) {
      // There will always be a promise so always declare it.
      var deferred = $q.defer();
      if (Cache[id]) {
          // Resolve the deferred $q object before returning the promise
          deferred.resolve(Cache[id]); 
          return deferred.promise;
      } 
      // else- not in cache 
      $http.get('/someUrl', {id:id}).success(function(data){
          // Store your data or what ever.... 
          // Then resolve
          deferred.resolve(data);               
      }).error(function(data, status, headers, config) {
          deferred.reject("Error: request returned status " + status); 
      });
      return deferred.promise;
  
  }
  

  控制器内部....

  somethingService.getSomething(5).then(    
      function(thing) {     // On success
          alert(thing);
      },
      function(message) {   // On failure
          alert(message);
      }
  );
  

  我希望它对某人有帮助 . 我没有发现其他答案非常明确 .

  回复于 2024-04-28T06:47:21+08:00
• 170

  如何在Angular 1.x中简单地返回预先解析的promise

  已解决的承诺：

  return $q.when( someValue );    // angular 1.2+
  return $q.resolve( someValue ); // angular 1.4+, alias to `when` to match ES6
  

  拒绝的承诺：

  return $q.reject( someValue );
  

  回复于 2024-04-28T06:47:21+08:00
• 0

  如果我想在数组或对象中实际缓存数据，我通常会这样做

  app.factory('DataService', function($q, $http) {
    var cache = {};
    var service= {       
      getData: function(id, callback) {
        var deffered = $q.defer();
        if (cache[id]) {         
          deffered.resolve(cache[id])
        } else {            
          $http.get('data.json').then(function(res) {
            cache[id] = res.data;              
            deffered.resolve(cache[id])
          })
        }
        return deffered.promise.then(callback)
      }
    }
  
    return service
  
  })
  

  DEMO

  回复于 2024-04-28T06:47:21+08:00
• 0

  您忘记初始化Cache元素

  function getSomething(id) {
      if (Cache[id]) {
          var deferred = $q.defer();
          deferred.resolve(Cache[id]); // <-- Can I do this?
          return deferred.promise;
      } else {
          Cache[id] = $http.get('/someUrl', {id:id});
          return Cache[id];
      }
  }
  

  回复于 2024-04-28T06:47:21+08:00
• 94

  我喜欢使用工厂从我的资源中获取数据 .

  .factory("SweetFactory", [ "$http", "$q", "$resource", function( $http, $q, $resource ) {
      return $resource("/sweet/app", {}, {
          "put": {
              method: "PUT",
              isArray: false
          },"get": {
              method: "GET",
              isArray: false
          }
      });
  }]);
  

  然后在这里像这样在服务中公开我的模型

  .service("SweetService",  [ "$q", "$filter",  "$log", "SweetFactory",
      function ($q, $filter, $log, SweetFactory) {
  
          var service = this;
  
          //Object that may be exposed by a controller if desired update using get and put methods provided
          service.stuff={
              //all kinds of stuff
          };
  
          service.listOfStuff = [
              {value:"", text:"Please Select"},
              {value:"stuff", text:"stuff"}];
  
          service.getStuff = function () {
  
              var deferred = $q.defer();
  
            var promise = SweetFactory.get().$promise.then(
                  function (response) {
                      if (response.response.result.code !== "COOL_BABY") {
                          deferred.reject(response);
                      } else {
                          deferred.resolve(response);
                          console.log("stuff is got", service.alerts);
                          return deferred.promise;
                      }
  
                  }
              ).catch(
                  function (error) {
                      deferred.reject(error);
                      console.log("failed to get stuff");
                  }
              );
  
              promise.then(function(response){
                  //...do some stuff to sett your stuff maybe fancy it up
                  service.stuff.formattedStuff = $filter('stuffFormatter')(service.stuff);
  
              });
  
  
              return service.stuff;
          };
  
  
          service.putStuff = function () {
              console.log("putting stuff eh", service.stuff);
  
              //maybe do stuff to your stuff
  
              AlertsFactory.put(service.stuff).$promise.then(function (response) {
                  console.log("yep yep", response.response.code);
                  service.getStuff();
              }).catch(function (errorData) {
                  alert("Failed to update stuff" + errorData.response.code);
              });
  
          };
  
      }]);
  

  然后，我的控制器可以包含它并将其暴露或者仅仅通过引用注入的Service来执行它在其上下文中所做的事情 .

  似乎工作正常 . 但我对角度有点新意 . *为了清楚起见，错误处理大多被遗漏

  回复于 2024-04-28T06:47:21+08:00