Question

我在服务中有这个代码，它对我有用。据我所知，$http.get()返回一个promise，promise是异步执行的，所以为什么我需要使用deffered.resolve(res.data)来返回我服务中的数据。非常感谢。

 data.posts = function(page, perPage, format, orderBy) {
        var deffered = $q.defer();
        $http.get(hostName, {
            params: {
                'page': page,
                'per_page': perPage,
                'filter[post_format]=': format,
                'filter[orderby]=': orderBy,
                'order': 'desc'
            }
        }).then(function(res) {
            deffered.resolve(res.data);
        })
        return deffered.promise;
    }

Answer 1

如果真的在服务中，则不需要推迟。服务中的方法从上面的$ http请求中返回promise。

function exampleService($http) {
    var data = this;
    data.post = function(page, perPage, format, orderBy) {
      return $http.get(hostName, {
          params: {
            'page': page,
            'per_page': perPage,
            'filter[post_format]=': format,
            'filter[orderby]=': orderBy,
            'order': 'desc'
          }
        }).then(function(res) {
          //do stuff with success
        })
        .catch(function(err) {
          //do stuff with error
        })
        .finally(function() {
          //optionally use this as well maybe if you had loading type overlay/icon
        });
    };
  }
  //preferred method as it makes methods available before the sevice has been returned  

function exampleService($http) {
  function post(page, perPage, format, orderBy) {
      return $http.get(hostName, {
          params: {
            'page': page,
            'per_page': perPage,
            'filter[post_format]=': format,
            'filter[orderby]=': orderBy,
            'order': 'desc'
          }
        }).then(function(res) {
          //do stuff with success
        })
        .catch(function(err) {
          //do stuff with error
        })
        .finally(function() {
          //optionally use this as well maybe if you had loading type overlay/icon
        });
    }
    //revealing module pattern 
  return {
    post: post,

  };
}

Answer 2

为什么要用它？因为作者并不了解更多。但是有many reasons not to use it。

代码应该是

data.posts = function(page, perPage, format, orderBy) {
    return $http.get(hostName, {
        params: {
            'page': page,
            'per_page': perPage,
            'filter[post_format]=': format,
            'filter[orderby]=': orderBy,
            'order': 'desc'
        }
    }).then(function(res) {
        return res.data;
    });
};

$ http得到一个承诺角度

2 个答案: