javascript - 带有 promise 的 Angular 异步上传文件

Question

我是 Angular 的新手，我对来自官方网站的文档有点困惑...

我有 Controller ，我有调用服务方法:

uploaderService.addImage(files);

和这样的服务:

.service('uploaderService', ['$http', 'settings', function ($http, settings) {

    var url = undefined;

    var addImage = function(files){
      var fd = new FormData();
      fd.append("file", files[0]);
      $http.post(settings.apiBaseUri + "/files", fd, 
        {
          withCredentials: true,
          headers: {'Content-Type': undefined },
          transformRequest: angular.identity
        })
        .success(function (data, status, headers, config) {         
            url = "temp.jpg";
        })
        .error(function (err, status) {
          console.log('operation failed, status: ' + status);
        });
    };

    var deleteImage = function(){      
    };   

    return {
      addImage: addImage,
      deleteImage: deleteImage
    }; 

我怎么能等到发布数据请求完成，然后传入 url 变量位置？我尝试了某某，但有些事情会变坏，需要帮助)

Answer 1

注入(inject) Angular 延迟:

.service('uploaderService', ['$http', '$q', 'settings', function ($http, $q, settings) {

然后在你的函数中使用它:

var addImage = function(files){

    var deferred = $q.defer();

    var fd = new FormData();
    fd.append("file", files[0]);
    $http.post(settings.apiBaseUri + "/files", fd, 
    {
        withCredentials: true,
        headers: {'Content-Type': undefined },
        transformRequest: angular.identity
    })
    .success(function (data, status, headers, config) {         
        url = "temp.jpg";
        deferred.resolve(data);
    })
    .error(function (err, status) {
        console.log('operation failed, status: ' + status);
        deferred.reject({msg: err});
    });

    return deferred.promise;
};

然后在你的 Controller 中:

uploaderService.addImage(files)
    .then(function(data){
        // success
        var url = data.url; // assuming the returned data of the ajax call contains an url variable
    }, function(error){
        // error
    }).finally(function(){
        // always
    });