AngularJS

$interpolate

HTML

<div ng-app="MyApp">
    <div ng-controller="MyController">
        <input ng-model="myName" type="text" placeholder="Type Your Name">
        <textarea ng-model="myTextarea" cols="30" rows="10"></textarea>
        <div ng-bind="interpolatedValue"></div>
    </div>
</div>

JavaScript

angular.module("MyApp", [])
.controller("MyController", function($scope, $interpolate){
    $scope.$watch("myTextarea", function(newVal, oldVal, scope){
        var interpolatedFunc = $interpolate(newVal);
        $scope.interpolatedValue = interpolatedFunc({sb: $scope.myName});
        //$scope.interpolatedValue = interpolatedFunc(scope);        
    });
    
});