Angular JS reset custom directive
<p>I want to reset this directive(clear the file chosen) when clear button is clicked. Currently even though when clear button is clicked , the file chosen is still exits and its not cleared.</p>

<p>test.html</p>

<pre><code>&lt;form class="form form-basic" id="testForm" name="testForm"&gt;

      &lt;div class="row"&gt;
        &lt;label class="col-md-6 control-label"&gt;File :&lt;/label&gt;
        &lt;div class="col-md-6"&gt;
            &lt;div class="form-group"&gt;
                &lt;input type="file" ng-model="test" on-read-file="loadContent($fileContent)" /&gt;
            &lt;/div&gt;
        &lt;/div&gt;
    &lt;/div&gt;


    &lt;button class="btn btn-primary" ng-click="clear()"&gt;Clear&lt;/button&gt;
&lt;/div&gt;
</code></pre>

<p></p>

<p>directive.js</p>

<pre><code>fileAccessModule.directive('onReadFile', function ($parse) {
return {
    restrict: 'A',
    scope: false,
    link: function (scope, element, attrs) {
        var fn = $parse(attrs.onReadFile);

        element.on('change', function (onChangeEvent) {
            var reader = new FileReader();

            reader.onload = function (onLoadEvent) {
                scope.$apply(function () {
                    fn(scope, {$fileContent: onLoadEvent.target.result});
                });
            };

            reader.readAsText((onChangeEvent.srcElement || onChangeEvent.target).files[0]);
        });
    }
};
</code></pre>

<p>});</p>

<p>testController.js</p>

<pre><code>    testControllerModule.controller('testController', function ($scope, $log, $location, deviceDetailsService) {
  $scope.clear = function () {
        $scope.connectionParams = null;
    };
$scope.loadContent = function ($fileContent) {
        $scope.connectionParams.privateKey = $fileContent;
    };
});
</code></pre>