Usages of jQuery's ajax crossDomain property?

Question

According to jQuery :

crossDomain (default: false for same-domain requests, true for cross-domain requests) Type: Boolean If you wish to f

Answer 1

If your are already specifying JSONP, then the crossDomain parameter doesn't do much. It just tells jQuery to ask for JSONP even if it's a local domain.

Let's say you are working on your machine with a local service that returns JSON or JSONP. You can use a plain $.ajax() call, which works fine. In production however, the server redirects your request to a different domain if you meet some special conditions. Prod needs to ask for JSONP, because sometimes the response comes from off-domain.

Making that $.ajax() call without crossDomain: true or datatype: 'jsonp' will assume the response can be plain JSON, so the code will fail in production.

You can also get cross-domain XML through prestidigitation like loading cross-domain XML through JSONP with YQL, which is really just wrapping it in JSONP.