Angular File Upload指令不更新控制器模型

Question

I am attempting to follow this [tutorial] but can't get it working.

My Angular controller is logging undefined for a model created in my directive. Here is a [JSFiddle] of it working created my author of tutorial.

The problem is the view can find $scope.myFile and but controller does not ( $scope.myFile is undefined ).

The view displays {{ myFile.name }} (as just example my-image.jpg ). The myFile variable is a JS object containing data on selected file. This works fine. The directive seems to be assigning the model the value of selected file (and thus displays it correctly in view).

<input file-model="myFile" type="file"/ >
<div class="label label-info">
  {{ myFile.name }}
</div>
<button ng-click="uploadDocs()">Click</button>

Here is the directive I got from this [tutorial] .

Since input type file can't use ng-model , this directive sets up the model to be associated with an file input, assigning to it every time the file fires change event.

directive('fileModel', [
  '$parse',
    function ($parse) {
      return {
        restrict: 'A',
        link: function(scope, element, attrs) {
          var model = $parse(attrs.fileModel);
          var modelSetter = model.assign;

          element.bind('change', function(){
            scope.$apply(function(){
              if (element[0].files.length > 1) {
                modelSetter(scope, element[0].files);
              }
              else {
                modelSetter(scope, element[0].files[0]);
              }
            });
          });
        }
      };
    }
  ]).

In the controller I just log $scope.myFile . This is called from the button in the HTML above. Ideally, I'd be uploading the files to server here, but I can't because $scope.myFile is undefined.

$scope.uploadDocs = function() {
  var file = $scope.myFile;
  console.log($scope.myFile);
};

Can someone tell me why the view would be recieving $scope.myFile but the controller logs undefined for $scope.myFile ?

Answer 1

I ran into the same problem when trying to access a directive's variable from the controller. In my case I could make myFile available to the controller, but I had to assign it to scope.$parent.$parent.myFile from within the directive. I didn't want to hard code in a depth of ancestry in order to access the variable, so I ended up using a service to share the variable between directive and controller:

.factory('fileService', function() {
    var files = [];
    return files;
})

My directive code changed to use the service instead of attrs.fileModel that was used in the tutorial:

.directive('fileModel', ['$parse', 'fileService', function ($parse, fileService) {
    return {
        restrict: 'A',
        link: function(scope, element) {
            element.bind('change', function(){
                scope.$apply(function(){
                    if (element[0].files != undefined) {
                        fileService.push(element[0].files[0]);
                        console.log('directive applying with file');
                    }
                });
            });
        }
    };
}])

Then, after injecting fileService into the controller I could access the file directly from fileService:

$scope.uploadDocs = function() {
    console.log(fileService);
};

Answer 2

This issue is seen in couple of Angular versions, where file object can't be set the scope variable. As a work around make, pass the field to controller, use this file object to upload ( not from scope)

HTML Form

<form>
    <div class="form-group">
                    <label for="myFileField">Select a file: </label> 
                    <input type="file" file-model="myFile" /> <label>File Name:</label> 
                    <input type="text" ng-model="filename"></input>
                </div>
                <button ng-click="uploadFile(myFile)" class="btn btn-primary">Upload File</button>
            </form>

Controller

 $scope.uploadFile = function (file1) {
            var file = $scope.myFile;  // this is undefined 
            console.log("My file =" +file1); // you get this 
            // Make http call to upload the file or make service call         
 }

Hope this solves the problem

Answer 3

我已经看过该教程但是选择使用这个库使得文件无缝上传： ng-file-upload

Answer 4

Try below solution: HTML code:

<div class="btn-header">
    <label for="attachment" class="control-label">Attachment</label>
    <div class="has-feedback">
        <input type="file" id="fileUpload" name="attachment" ng-disabled="BRPTab.BRPTelePhonyandTestScipt.Checked"
               class="form-control" data-ak-file-model="BRPTab.tutorial.attachment" />
        <span class="form-control-feedback" aria-hidden="true"></span>
        <div class="help-block with-errors"></div>
    </div>
</div>

Code For Service:

    AppService.factory("entityService", ["akFileUploaderService", function(akFileUploaderService) {
    var saveTutorial = function(tutorial, url) {

        return akFileUploaderService.saveModel(tutorial, url);
    };
    return {
        saveTutorial: saveTutorial
    };
}]);

(function() {
    "use strict"
    angular.module("akFileUploader", [])
        .factory("akFileUploaderService", ["$q", "$http",
            function($q, $http) {
                var getModelAsFormData = function(data) {
                    var dataAsFormData = new FormData();
                    angular.forEach(data, function(value, key) {
                        dataAsFormData.append(key, value);
                    });

                    return dataAsFormData;
                };

                var saveModel = function(data, url) {


                    var deferred = $q.defer();
                    $http({
                        url: url,
                        method: "POST",
                        //data:
                        //    {
                        //        tutorial: getModelAsFormData(data),
                        //        Object: Obj
                        //    },
                        //params: Indata,
                        data: getModelAsFormData(data),
                        transformRequest: angular.identity,
                        headers: {
                            'Content-Type': undefined
                        }
                    }).success(function(result) {

                        deferred.resolve(result);
                    }).error(function(result, status) {
                        deferred.reject(status);
                    });
                    return deferred.promise;
                };

                return {
                    saveModel: saveModel
                }

            }
        ])
        .directive("akFileModel", ["$parse",
            function($parse) {
                return {
                    restrict: "A",
                    link: function(scope, element, attrs) {
                        var model = $parse(attrs.akFileModel);
                        var modelSetter = model.assign;
                        element.bind("change", function() {
                            scope.$apply(function() {
                                modelSetter(scope, element[0].files[0]);
                            });
                        });
                    }
                };
            }
        ]);
})(window, document);

Let me know if you guys are facing any issue.

Answer 5

try this code

                <html>

               <head>
                  <script src = "https://ajax.googleapis.com/ajax/libs/angularjs/1.3.14/angular.min.js"></script>
               </head>

               <body ng-app = "myApp">

                  <div ng-controller = "myCtrl">
                     <input type = "file" file-model = "myFile"/>
                     <button ng-click = "uploadFile()">upload me</button>
                  </div>

                  <script>
                     var myApp = angular.module('myApp', []);

                     myApp.directive('fileModel', ['$parse', function ($parse) {
                        return {
                           restrict: 'A',
                           link: function(scope, element, attrs) {
                              var model = $parse(attrs.fileModel);
                              var modelSetter = model.assign;

                              element.bind('change', function(){
                                 scope.$apply(function(){
                                    modelSetter(scope, element[0].files[0]);
                                 });
                              });
                           }
                        };
                     }]);

                     myApp.service('fileUpload', ['$http', function ($http) {
                        this.uploadFileToUrl = function(file, uploadUrl){
                           var fd = new FormData();
                           fd.append('file', file);

                           $http.post(uploadUrl, fd, {
                              transformRequest: angular.identity,
                              headers: {'Content-Type': undefined}
                           })

                           .success(function(){
                           })

                           .error(function(){
                           });
                        }
                     }]);

                     myApp.controller('myCtrl', ['$scope', 'fileUpload', function($scope, fileUpload){
                        $scope.uploadFile = function(){
                           var file = $scope.myFile;

                           console.log('file is ' );
                           console.dir(file);

                           var uploadUrl = "/fileUpload";
                           fileUpload.uploadFileToUrl(file, uploadUrl);
                        };
                     }]);

                  </script>

               </body>
            </html>