ngUploadBtn.js

app.directive('uploadButton', function($parse, $compile) {
  return {
    restrict: 'E',
    replace: true,
    transclude: true,
    template: '<span class="upload-button {{class}}">' +
        '<span ng-transclude></span>' +
        '<input type="file">' +
      '</span>',
    link: function(scope, element, attrs) {
      element.find('input').bind('change', function() {
        var fd = new FormData();
        fd.append('uploadFile', this.files[0]);
        var xhr = new XMLHttpRequest();
        // xhr.upload.addEventListener("progress", function(e) {
        //   var fn = $parse($scope.progress);
        //   $scope.$apply(function () {
        //     if (fn) { fn($scope, { $event: e }); }
        //   });
        // }, false);
        xhr.addEventListener("load", function(e) {
          var fn = $parse(attrs.complete);
          scope.$apply(function () {
            if(fn) { fn(scope, { $data: xhr.responseText, $status: xhr.status }); } 
          });
        }, false);
        xhr.open("POST", attrs.action);
        xhr.send(fd);
        
      });
    }
  };
});

uploadbtn.css

.upload-button {
  position: relative;
  overflow: hidden;
  margin-right: 4px;
}
.upload-button input {
  position: absolute;
  top: 0;
  right: 0;
  margin: 0;
  opacity: 0;
  filter: alpha(opacity=0);
  transform: translate(-300px, 0) scale(4);
  font-size: 23px;
  direction: ltr;
  cursor: pointer;
}