We are developing a bookmarklet, and we use JSONP to communicate with the server. We have reached a phase when we must send from the browser to server parameters that will exceed the well know 2000ish URL length.
We are looking for solutions to overcome this problem. Please note that the bookmarklet will be executed on 3rd party URLS, some of them are HTTP and some of them HTTPS, and JSONP is limited to GET requests only
The only thing I can think of would be to do multiple requests – throw an id in with the request and setup the state server side in a persistent way and then request the data.
Multiple requests is pretty ugly too – what if one message gets lost while another makes it, etc.
Unfortunately, JSONP doesn’t have a lot of flexibility since its just simulating script loads – and theres really no way around this with current browser security standards.