Question

When I loaded a web page after submitting something into a javascript-type “form” I looked at the HTTP headers with the Firefox add-on. Everything in the headers make sense except for 16 random characters in the middle that always came after the word “callback”. I don’t know what they mean or where they come from.

These are all from SEPERATE “form submissions” if you will.

“http://www.locationary.com/access/proxy.jsp?ACTION_TOKEN=proxy_jsp$JspView$SaveAction&callback=callback8FDRUTrnQgGI2iuZ&inPlaceID=1003168722&xxx_c_1_f_987=http%3A%2F%2Fwww.yellowpages.com%2Fdallas-tx%2Fmip%2Fdallas-womens-foundation-13224281%3Flid%3D13224281”

“http://www.locationary.com/access/proxy.jsp?ACTION_TOKEN=proxy_jsp$JspView$SaveAction&callback=callbackPAgvDXBbZuLXbAHw&inPlaceID=1014875244&xxx_c_1_f_987=http%3A%2F%2Fwww.yellowpages.com%2Fmorrill-me%2Fmip%2Fshear-talent-country-style-14741614%3Flid%3D14741614”

“http://www.locationary.com/access/proxy.jsp?ACTION_TOKEN=proxy_jsp$JspView$SaveAction&callback=callback5GgVkaOind0ySooX&inPlaceID=1015406723&xxx_c_1_f_987=http%3A%2F%2Fwww.yellowpages.com%2Fgalesburg-mi%2Fmip%2Fmichigan-grower-products-8776287%3Flid%3D8776287”

As you can see, they all start out with the same thing:

“http://www.locationary.com/access/proxy.jsp?ACTION_TOKEN=proxy_jsp$JspView$SaveAction&callback=callback”

But after that, there is always a set of 16 seemingly random characters. I understand the rest of this “url” but these 16 characters don’t make sense to me. Is there any way to generate them or get them before the request is sent?

Thanks!

Answer 1

These are almost certainly “AJAX” requests, being used as JSONP. The callback... value is the name of a dynamically-created JavaScript function to handle the results of the data returned by the HTTP request.

I’d recommend using Firebug to view all of this – it may help shed a little more light on things.