Binding not working between components AngularJS

I do have a problem with bindings in AngularJS. I created 2 components (leftForm and rightForm) those components have an input and a p element. This p element is a count number that increases when you click the input button of the other component.

For example I click in leftButton (left component) then the count number in the right button(right component) needs to be incremented, I've accomplished this, but the problem is that I can't see those variables in the view, so I'm guessing I'm doing something wrong with the binding. Here is my code:

angular.module('testApp', [])
    .controller('Controller', function ($rootScope) {
        var vm = this;
        $rootScope.valueLeft = 0;
        $rootScope.valueRight = 0;

        vm.rightButton = function () {
            $rootScope.valueLeft += 1;
        }

        vm.leftButton = function () {
            $rootScope.valueRight += 1;
        }

    })

    .component('leftForm', {
        templateUrl: 'leftForm.html',
        controller: 'Controller',
        controllerAs: 'vm',
        bindings: {
            onUpdate: '&'
        }
    })

    .component('rightForm', {
        templateUrl: 'rightForm.html',
        controller: 'Controller',
        controllerAs: 'vm',
        bindings: {
            onUpdate: '&'
        }
    });

<!doctype html>
<html ng-app="testApp">
<head>
    <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.6.1/angular.min.js"></script>
    <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.3/css/bootstrap.min.css"
          crossorigin="anonymous">
</head>

<body>
<div ng-controller="Controller as vm">
    <div class="container" style="text-align: center; padding-top: 2%;">
        <div class="row" style="padding: 2%; border: 1px solid;">
            <div class="col">
                <left-form></left-form>
            </div>
            <div class="col"></div>
            <div class="col">
                <right-form></right-form>
            </div>
        </div>
    </div>
</div>
</body>

<script type="text/ng-template" id="leftForm.html">
    <p>{{$rootScope.valueLeft}}</p>
    <button ng-click="vm.leftButton()">+1</button>
</script>

<script type="text/ng-template" id="rightForm.html">
    <p>{{$rootScope.valueRight}}</p>
    <button ng-click="vm.rightButton()">+1</button>
</script>

</html>

Solution

To access $rootScope variables in your templates you can just use $root as a reference to the $rootScope as {{$root.valueLeft}} and {{$root.valueRight}}. Here is a working example:

angular.module('testApp', [])
    .controller('Controller', function ($rootScope) {
        var vm = this;
        $rootScope.valueLeft = 0;
        $rootScope.valueRight = 0;

        vm.rightButton = function () {
            $rootScope.valueLeft += 1;
        }

        vm.leftButton = function () {
            $rootScope.valueRight += 1;
        }

    })

    .component('leftForm', {
        templateUrl: 'leftForm.html',
        controller: 'Controller',
        controllerAs: 'vm',
        bindings: {
            onUpdate: '&'
        }
    })

    .component('rightForm', {
        templateUrl: 'rightForm.html',
        controller: 'Controller',
        controllerAs: 'vm',
        bindings: {
            onUpdate: '&'
        }
    });

<html ng-app="testApp">
<head>
    <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.6.1/angular.min.js"></script>
    <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.3/css/bootstrap.min.css"
          crossorigin="anonymous">
</head>

<body>
<div ng-controller="Controller as vm">
    <div class="container" style="text-align: center; padding-top: 2%;">
        <div class="row" style="padding: 2%; border: 1px solid;">
            <div class="col">
                <left-form></left-form>
            </div>
            <div class="col"></div>
            <div class="col">
                <right-form></right-form>
            </div>
        </div>
    </div>
</div>
</body>

<script type="text/ng-template" id="leftForm.html">
    <p>{{$root.valueLeft}}</p>
    <button ng-click="vm.leftButton()">+1</button>
</script>

<script type="text/ng-template" id="rightForm.html">
    <p>{{$root.valueRight}}</p>
    <button ng-click="vm.rightButton()">+1</button>
</script>

</html>