12.10. Cross-domain Ajax

Cross-domain Ajax refers to a scenario in which an Ajax request is sent from a web page or portal page, downloaded from domain X, to a server that is in domain Y.

Let’s say your web portal’s domain name is www.my-bookportal.com (domain X), and one of the portlets in your web portal needs to asynchronously access a servlet hosted by www.your-bookportal.com (domain Y). You might think that you could easily go ahead and create an XMLHttpRequest object and send an Ajax request to www.your-bookportal.com, but it isn’t so simple. Web browsers limit Ajax requests from a web page or portal page to the server from which the web page or portal page was downloaded. So, in this scenario, you could only send Ajax requests to www.mybookportal.com.