Binding ng-repeat and ng-model from controller - angularjs

Question

I'm new to AngularJS. I'm trying to build a form with ng-repeat and having trouble wrapping my head around the angular stuff.
This is my angular controller:
// Create the 'products' controller
angular.module('products').controller('ProductsController', ['$scope', '$routeParams', '$location', 'Authentication', 'Products',
function($scope, $routeParams, $location, Authentication, Products) {
// Expose the Authentication service
$scope.authentication = Authentication;
$scope.productProperty = {
productTitle: {slug: 'productTitle', label: 'Product Title', value: '', placeholder: 'Product Title'},
productCode: {slug: 'productCode', label: 'Product Code', value: '', placeholder: 'Product Code'},
productModel: {slug: 'productModel', label: 'Product Model', value: '', placeholder: 'Product Model'},
productColor: {slug: 'productColor', label: 'Product Color', value: '', placeholder: 'Product Color'}
};
// Create a new controller method for creating new products
$scope.create = function() {
// Use the form fields to create a new product $resource object
var product = new Products({
productTitle: this.productTitle,
productCode: this.productCode,
productModel: this.productModel,
productColor: this.productColor
});
// Use the product '$save' method to send an appropriate POST request
product.$save(function(response) {
// If an product was created successfully, redirect the user to the product's page
$location.path('products/' + response._id);
}, function(errorResponse) {
// Otherwise, present the user with the error message
$scope.error = errorResponse.data.message;
});
};
}
]);
HTML:
<!-- The create product view -->
<section data-ng-controller="ProductsController">
<h1>New Product</h1>
<!-- The new product form -->
<form data-ng-submit="create()" novalidate>
<div class="row" data-ng-repeat="(keyAssets, valueAssets) in productProperty">
<div>
<label for="{{productProperty[keyAssets]['slug']}}">{{productProperty[keyAssets]['label']}}</label>
<div>
<input type="text" data-ng-model="productProperty[keyAssets]['slug']" id="{{productProperty[keyAssets]['slug']}}" placeholder="{{productProperty[keyAssets]['placeholder']}}" required>
</div>
</div>
</div>
<div>
<input type="submit">
</div>
<!-- The error message element -->
<div data-ng-show="error">
<strong data-ng-bind="error"></strong>
</div>
</form>
</section>
I'm trying to get the 'data-ng-model' set to something unique in each instance of the data-ng-repeat. But I'm not getting the desired output.
I want something like the following output:
<!-- The create product view -->
<section data-ng-controller="ProductsController">
<h1>New Product</h1>
<!-- The new product form -->
<form data-ng-submit="create()" novalidate>
<div>
<label for="productTitle">Product Title</label>
<div>
<input type="text" data-ng-model="productTitle" id="productTitle" placeholder="Product Name" required>
</div>
</div>
<div>
<label for="productCode">Product Code</label>
<div>
<input type="text" data-ng-model="productCode" id="productCode" placeholder="Product Code" required>
</div>
</div>
<div>
<label for="productModel">Product Model</label>
<div>
<input type="text" data-ng-model="productModel" id="productModel" placeholder="Product Model" required>
</div>
</div>
<div>
<label for="productColor">Product Color</label>
<div>
<input type="text" data-ng-model="productColor" id="productColor" placeholder="Product Color" required>
</div>
</div>
<div>
<input type="submit">
</div>
<!-- The error message element -->
<div data-ng-show="error">
<strong data-ng-bind="error"></strong>
</div>
</form>
How can I get the 'data-ng-model' set to something unique in each instance of the ng-repeat?