File pick with Angular JS

Angular doesn't yet support ng-change for input[type=file] so you have to roll onchange implementation yourself.

First, in the HTML, define Javascript for onchange as follows:

<input ng-model="photo"
       onchange="angular.element(this).scope().file_changed(this)"
       type="file" accept="image/*" />

And then in your Angular controller code, define the function:

$scope.file_changed = function(element) {

     $scope.$apply(function(scope) {
         var photofile = element.files[0];
         var reader = new FileReader();
         reader.onload = function(e) {
            // handle onload
         };
         reader.readAsDataURL(photofile);
     });
};

I used above method trying to load a preview image when new file is selected, however it didnt work when I tried it like that:

$scope.file_changed = function(element, $scope) {

     $scope.$apply(function(scope) {
         var photofile = element.files[0];
         var reader = new FileReader();
         reader.onload = function(e) {
            $scope.prev_img = e.target.result;
         };
         reader.readAsDataURL(photofile);
     });
});

I digged more into it and found that the $scope.$apply should be inside the reader.onLoad otherwise changing a $scope variables wont work, so I did the following and it worked:

$scope.file_changed = function(element) {

        var photofile = element.files[0];
        var reader = new FileReader();
        reader.onload = function(e) {
            $scope.$apply(function() {
                $scope.prev_img = e.target.result;
            });
        };
        reader.readAsDataURL(photofile);
 };