Upgrade to 1.x.x - TypeError: "Uploader" must be an instance of FileUploader

[davidwparker]

When migrating, following the guide: https://github.com/nervgh/angular-file-upload/wiki/Migrate-from-0.x.x-to-1.x.x

I now get the following error whenever I use any of the directives:

TypeError: "Uploader" must be an instance of FileUploader
    at link (http://localhost:3000/assets/angular/angular-file-upload.js?body=1:1231:27)
    at nodeLinkFn (http://localhost:3000/assets/angular/angular.js?body=1:6228:13)
    at compositeLinkFn (http://localhost:3000/assets/angular/angular.js?body=1:5638:15)
    at compositeLinkFn (http://localhost:3000/assets/angular/angular.js?body=1:5641:13)
    at nodeLinkFn (http://localhost:3000/assets/angular/angular.js?body=1:6222:24)
    at http://localhost:3000/assets/angular/angular.js?body=1:6422:13
    at http://localhost:3000/assets/angular/angular.js?body=1:7574:11
    at wrappedCallback (http://localhost:3000/assets/angular/angular.js?body=1:10950:81)
    at wrappedCallback (http://localhost:3000/assets/angular/angular.js?body=1:10950:81)
    at http://localhost:3000/assets/angular/angular.js?body=1:11036:26

The element:

<input nv-file-select uploader="{{uploader}}" type="file" multiple="" class="hidden-file" id="attachment{{uploader._timestamp}}">

Any thoughts on what I should be looking at?

[davidwparker]

It appears I'm having some race conditions. It seems that ng-file-select directive is trying to read from the uploader attribute before it's ready to be used (my own directive, which has ng-file-select within it, creates the uploader). So it's still not created when it's called, but then it's created a moment later and then it's usable.

[nervgh]

Did you see this?

[davidwparker]

@nervgh - yeah, I have something similar, but I'm calling the whole thing from within a directive. So it's something like:

.directive('attachmentsBar', function(FileUploader) {
  return {
    restrict: 'E',
    replace: true,
    templateUrl:'attachments/_bar.html',
    link: function(scope, element, attrs) {
      var uploader = scope.uploader = new FileUploader();
...

But what ends up happening is it hits this new code:

throw new TypeError('"Uploader" must be an instance of FileUploader');

within:

.directive('nvFileSelect', ['$parse', 'FileUploader', function($parse, FileUploader) {
        return {
            link: function(scope, element, attributes) {
                var uploader = scope.$eval(attributes.uploader);

                if (!(uploader instanceof FileUploader)) {
                    throw new TypeError('"Uploader" must be an instance of FileUploader');
                }

                var object = new FileUploader.FileSelect({
                    uploader: uploader,
                    element: element
                });
            }
        };
    }])

But because of the way the directive works (calling the nv-file-select directive), it seems that nv-file-select doesn't wait until the uploader is created, so it's null when it first gets into the directive.

[nervgh]

You can use ng-if directive:

<element ng-if="case">
    <input type="file" nv-file-select uploader="uploader"/>
</element>

[davidwparker]

@nervgh - that wouldn't work either.

Here's a plunker of my exact problem:
http://plnkr.co/edit/SnoWSQDjqFrKArST4cDR?p=info

[nervgh]

For example:

1. ng-if
2. directive.compile
3. rootScope & instance of FileUploader

[davidwparker]

Thanks @nervgh - I think I should be able to get it working with those examples.

[elise-fastpay]

What was the solution to this problem?

[davidwparker]

@elise-fastpay -

I have the following template (used in a directive "A"):

<input nv-file-select uploader="uploader" type="file" multiple class="hidden-file" id="attachment{{uploader._timestamp}}" />

With that directive being called from another template in another directive "B":

        <attachments-bar uploader="uploader"></attachments-bar>

And the uploader being created in directive "B" compile/pre:

compile: function() {
      return {
        pre: function(scope, element, attrs) {
          scope.uploader = new FileUploader();
        },

[jackhsu978]

@nervgh the ng-if trick works for me. thanks!

[daleholborow]

I think, to avoid confusion, in @davidwparker 's solution, the uploader=uploader attribute on the attachments-bar directive definition is unnecessary, the nv-file-select uploader=x refers to the scope.x = new FileUploader... i was able to get this working without the additional attribute but found it confusing figuring out which "uploader" was which giving the same name being used all throughout the code. Hope this helps make it even clearer. Thanks guys, i was tearing my hair out for a while on this problem

[davidwparker]

@daleholborow - I only had to do that because I had an inner directive that needed access to the same Uploader as the parent directive. Works pretty well and is necessary for the two to talk.