angular factory for angular firebase upload

firebaseStorage.js

.factory('$firebaseStorage', ['$q', function($q) {
  var $firebaseStorage = {
    _ref: firebase.storage().ref(),
    upload: function(_path, _file, _onProgress) {
      return $q(function(resolve, reject) {
        if (!_path) {
          reject(new Error('no path'));
        }
        else if (!_file) {
          reject(new Error('no file'));
        }
        else {
          var storagePath = _path + _file.name;
          var storageRef = $firebaseStorage._ref.child(storagePath);
          var uploadTask = storageRef.put(_file);
          uploadTask.on('state_changed',
            function(snapshot) {
              // Get task progress, including the number of bytes uploaded and the total number of bytes to be uploaded
              // Put $scope.$digest() in the callback to update view
              var progress = (snapshot.bytesTransferred / snapshot.totalBytes) * 100;
              if (_onProgress) {
                _onProgress(progress);
              }
            }, function(error) {
              switch (error.code) {
                case 'storage/unauthorized':
                  // User doesn't have permission to access the object
                  break;
                case 'storage/canceled':
                  // User canceled the upload
                  break;
                case 'storage/unknown':
                  // Unknown error occurred, inspect error.serverResponse
                  break;
              }
              reject(error);
            }, function() {
              // Upload completed successfully, now we can get the download URL
              // Custom Metadata
              /*
              storageRef.updateMetadata({
                customMetadata: {
                  'fileName:' : _file.name
                }
              });
              */
              uploadTask.snapshot.ref.getDownloadURL().then(function(downloadURL) {
                resolve(downloadURL);
              });
            });
        }
      });
    }
  };
  return $firebaseStorage;
}]);

Updated for firebase js sdk ^5.0 (downloadURL now needs to be retrieved in a promise function), according to https://firebase.google.com/docs/storage/web/upload-files