title: Making an external API call from Javascript.
body: <p>Am I allowed to make an API call directly from Javascript to an external API ( in my case <a href="http://isbndb.com/docs/api/20-structure.html" rel="nofollow">http://isbndb.com/docs/api/20-structure.html</a> ) using the XMLHttpRequest object? If not how do I go about fetching data from this source? Do I have to add a PHP back end which makes the API call and then returns data to the front end JS? Is there any other way to fetch data without the need for back end code? I did some research online and found that this is possible in jQuery if the data format is JSON. But how do I do this with XML data? </p>