I have not used this framework, but it certainly looks interesting. If I were writing a complicated GWT application, this LGPL framework would certainly be worth looking at.

Thanks for pointing out that I could have used plain old javascript to execute ‘my_fcn’. I used the term JSONP because of the article that introduced me to the concept ( http://code.google.com/support/bin/answer.py?answer=65632&topic=11368 ). You have to admit that JSONP is catchier than “just javascript”.

I believe what I’m calling JSON ({“msg”:”plain json”}) is JSON, according to the RFC you pointed me to. It’s a fair argument that using JSON in this case is overkill, since it really comes into its own when tranferring complicated data structures.

Thanks for the comments about the term ‘payload’ being outmoded–while I have heard about REST, I’m afraid I’m not as up to speed on the concept as I should be.

And thanks for your comments in general.

From the bit of looking, I see that the window.name apparently has no limit: http://www.boutell.com/newfaq/creating/scriptpass.html (that post does mention some security concerns).

First, “JSONP” having “JSON” in its name is an heresy, it’s just JavaScript; your example could have been written:
(function() { var obj={}; obj.msg = ‘plain jsonp’; my_fcn(obj); })();
and it would be clear that it’s not JSON (RFC 4627; see http://json.org for an overview)

What you’re calling “JSON” is just JavaScript too.

Finally, calling an URL “payload” takes us back in the days where people was saying “How to do a POST with a link? I don’t want to use a GET because it makes URLs ugly” (that was 10 years ago). Hopefully now people know about “REST principles” (“resources” and how URLs identify them) and HTTP caching.

http://timepedia.blogspot.com/2008/07/cross-domain-formpanel-submissions-in.html

Cheers

Cameron