Question

I am following this tutorial to build my first Asp.net Web API in a Web Form website but I am facing an issue. I have created two projects:

1. host project for the definition of the web service
2. client project to consume the web
   service.

Now my issue is that if I navigate to my web api URL using a web browser ex) http://localhost:39930/api/products/ then this works perfectly and an XML or Json data is returned depending on the browser.

However, if I use the web service URL of the in my client website then nothing get returned!

Here is how I call the web service from my client website:

<table>
    <thead>
        <tr>
            <th>Name</th>
            <th>Price</th>
        </tr>
    </thead>
    <tbody id="products">
    </tbody>
</table>

 <script type="text/javascript">
     function getProducts() {
         $.getJSON("http://localhost:39930/api/products",
             function (data) {
                 $('#products').empty(); // Clear the table body.

                 // Loop through the list of products.
                 $.each(data, function (key, val) {
                     // Add a table row for the product.
                     var row = '<td>' + val.Name + '</td><td>' + val.Price + '</td>';
                     $('<tr/>', { text: row })  // Append the name.
                         .appendTo($('#products'));
                 });
             });
     }

     $(document).ready(getProducts);
</script>

And here is a snapshot of the request in firebug:

Notice that the response is empty.

So, am I doing something wrong here? Is there some configuration that should be added to allow a service to be remotely called?

Thanks in advance.

Answer 1

It is because your host project and client project are running on different ports which is violating the same origin policy and its prohibited. See the details here http://en.wikipedia.org/wiki/Same_origin_policy

If you want this to work, you can use jsonp instead of json. Have a look at this article http://www.jquery4u.com/json/jsonp-examples/#.UISVAo3iYsc