JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.0.7/angular.js"></script>
<div ng-controller="Ctrl">
    {{data}}
    <br>
    <chart ng-model='data'></chart>
</div>

JavaScript

var App = angular.module('myApp', []);

function Ctrl($scope, $timeout) {
   
    $scope.data="Initial";
    
    $timeout(function(){
        $scope.data="Updated"}, 1)
}

App.directive('chart', function(){
    return{
        restrict: 'E',
        link: function(scope, elem, attrs){
            scope.$watch(attrs.ngModel, function(v){
                alert(v)
                elem.html("Data="+v);
            });
        }
    };
});