Slide 38 - Use of $watch by Angular

Snippet

<div data-ng-controller="ProductController" id="productForm">
	Name *: <input type="text" id="inputName" data-ng-model="product.name"/>,
	Price *: <input type="number" id="inputPrice" data-ng-model="product.price"/> €,
	Quantity *: <input type="number" id="inputQty" data-ng-model="product.qty"/>
	<br/> <i id="errorMsg">{{mandatoryMsg}}</i>
</div>

snippet

var ProductController = function($scope) {
	
	$scope.product = { name: "", price: null, qty: null };
	
	tmpMessage = "All fields are mandatory!";
	
	$scope.$watch('product', function(newValue, oldValue) {
	    if(newValue.name === "" || newValue.price === null || newValue.qty === null){
	        $scope.mandatoryMsg = tmpMessage;    
	    } else {
	        $scope.mandatoryMsg = "";
	    }
		
	}, true);
};