AngularJS Example:

HTML

<div ng-app="app">
    <div ng-controller="Ctrl">
        <input ng-model="myFile" onchange="angular.element(this).scope().onchange(this.files)" type="file" />
    </div>
</div>

JavaScript

var app = angular.module("app", []);

function Ctrl($scope) {
    $scope.onchange = function (files) {
        var file = files[0];
        var reader = new FileReader();

        reader.onload = function (e) {
            //doing some stuff here
            console.log(e)

            //finally clear the file for new selection
            $scope.myFile = null;
            $scope.$apply();
        };
        reader.readAsText(file);
    };
}