What would be the best client side javascript based XForms processor?
I'm trying to migrate plugin (activeX) based Xforms processing solution to a javascript based client side processor. But the migrating XForm does not work properly in any of the client side solutions I found. They give various unfriendly errors and its very hard to find why as it is unable to debug. Ideally migration should work without any changes isn't it? How should I approach my goal ?
I am working on Orbeon Forms, so my opinion is biased and I will refrain from answering your question about the "best solution" ;).
But since you already several implementations, I'll recommend you post about the specific issues you encountered either here on StackOverflow, or on the mailing list / forum specific to one of the implementation you tried. When doing so, pointing to a simple example that illustrates the problem you're seeing is always a plus.
I really don't have opinion which is the best, but I do participate in XSLTForms mailing list and there is a lot of activity there. People ask questions, get answers and the bugs they discover are often fixed. I suggest to give XSLTForms another try and take your problems into mailing list, if you haven't done it already. I think it's the only actively developed client side solution at the moment.
I too will refrain from saying which is the best solution. ;)
On your particular problem though, either you were using a non-standard feature in formsPlayer, or you were you were using a standard feature, but it is not implemented in the processor you are trying to move to.
Without seeing the form, I couldn't say.
On your other question about JavaScript client-side engines, you might want to take a look at [backplanejs][1]. It's a JavaScript library, built on YUI, and which provides an XForms processor and an RDFa parser, amongst other things. (The XForms support comes from the Ubiquity XForms engine, which we're working on with IBM -- they're keen to add Dojo support, and others want to add jQuery support.)
There will also be a successor to formsPlayer available soon, which will be a set of installable extensions to backplanejs, rather than a self-contained application.
[1]: http://backplanejs.googlecode.com/ backplanejs
You may also want to check out the EMC XForms Formula Engine (free for dev use); it seems like the most mature client side implementation right now... https://community.emc.com/docs/DOC-3100