AngularDart: file input model directive - dart

Question

I'm trying to make a directive similar to ng-model to work with file inputs. I am new to AngularDart so don't really know how to go about doing this.
Here is some code I managed to write by looking at the ng-model source files but it (obviously) doesn't work.
#Decorator(
selector: 'input[type=file][file-model]',
map: const {'file-model': '&filesSelected'})
class FileModel {
final InputElement inputElement;
String expression;
final Scope scope;
String _inputType;
List<File> files;
var filesSelected;
FileModel(this.inputElement, this.scope, NodeAttrs attrs) {
expression = attrs["file-model"];
inputElement.onChange.listen((event) {
files = inputElement.files;
filesSelected(files);
});
}
}
Any suggestions?

Answer 1

I've got it working.
#Decorator(
selector: 'input[type=file][file-model]',
map: const {'file-model': '&filesSelected'})
class FileModel {
Element inputElement;
String expression;
final Scope scope;
String _inputType;
List<File> files;
var listeners = {};
FileModel(this.inputElement, this.scope) {
}
initListener(var stream, var handler) {
int key = stream.hashCode;
if (!listeners.containsKey(key)) {
listeners[key] = handler;
stream.listen((event) => handler({r"files": (inputElement as InputElement).files}));
}
}
set filesSelected(value) => initListener(inputElement.onChange, value);
}
Usage: <input type="file" multiple file-model="cmp.filesSelected(files)">

Answer 2

For getting the files upon the change event, you can also just pass them via $event.target.files. Example:
import 'package:angular2/core.dart';
#Component(
selector: 'my-app',
template: r'''
<h1>{{title}}</h1>
<input class="btn" type="file" (change)="onFileUpload($event.target.files)">
''')
class AppComponent {
String title = 'File transfer';
onFileUpload(List<File> files) {
if (files == null) return;
// read file content as dataURL
final File file = files[0];
final FileReader reader = new FileReader();
reader.onLoad.listen((_) {
print(reader.result);
});
reader.readAsDataUrl(file);
}
}