很少$ scope变量值未定义

Question

我有一个添加路线表格。我能够从视图到控制器获取距离，描述$scope值，但是对于一个字段终端站点，在提交表单之前是自动生成的值，在$ scope值中是未定义的。 你有没有人能告诉我什么是错的，这是任何回电/加载问题。

  <form class="well form-horizontal" id="addRouteForm" ng-submit="r.addRoute()">
    <fieldset>
        <!-- Route Description-->
        <div class="form-group">
            <label class="control-label">Description</label>
            <div class="inputGroupContainer">
                <div class="input-group">
                    <span class="input-group-addon"><i class="glyphicon glyphicon-pencil"></i></span>
                    <textarea name="description" ng-model="route.description" placeholder="Enter route description" class="form-control" type="text" required></textarea>
                </div>
            </div>
        </div>
        <!-- Route distance-->
        <div class="form-group">
            <label class="control-label">Route Distance</label>
            <div class="inputGroupContainer">
                <div class="input-group">
                    <span class="input-group-addon"><i class="glyphicon glyphicon-road"></i></span>
                    <input name="distance" ng-model="route.distance" placeholder="12.56 km" class="form-control" type="number" step="00.01" required>
                </div>
            </div>
        </div>
        <!-- Route distance-->
        <div class="form-group">
            <label class="control-label">Terminal stop</label>
            <div class="inputGroupContainer">
                <div class="input-group">
                    <span class="input-group-addon"><i class="glyphicon glyphicon-road"></i></span>
                    <input name="terminalstop" ng-model="route.routeTerminalStop" id="terminalstop" value={{route.routeTerminalStop}} placeholder="Terminal stop" class="form-control" type="text">
                </div>
            </div>
        </div>
    </fieldset>
    <button type="submit" id="submitRoute" value="addRoute" class="btn btn-warning btn-sm" data-placement="top" ng-disabled="r.isNotLoaded" ng-show="saveRoute">Save <span class="glyphicon glyphicon-send"></span>
    </button>

ctrl.js：

vm.addRoute = function () {

    vm.isNotLoaded = true;            
    vm.responseMessage = "";

    var route = $scope.route;
    var y = document.getElementById("terminalstop").value; 
    var x = $scope.routeTerminalStop;

通过var y，我能够得到但是var x未定义。路线的终点站是未定义的。