I'm just now catching up on some of this....but I was wondering.....if you configure "ignoreReturnValue" or "abortIfContextValueTrueOrNull" or "whatchaMaCallit", then how would you (in a looked up chain) tell the calling chain to abort without having to throw an exception?
When a command returns false, that is intended as a sign to its caller that it thinks it has "finished". ChainBase interprets a "true" return from a command as a sign to stop executing the chain. It also returns whatever it received from the last command it executed, so the fundamental design denies the possibility of autonomous subchains and commands. I can see where this would sometimes be the way you'd want it, but I think that if it's the only way, one must configure chains relatively obtusely in order to ensure that conditional commands never get called, or, as in Struts, one must burden commands with more contextual knowledge than they should have -- there's absolutely no reason an "ExecuteAction" command should care if the form was valid or not; something else should prevent it from being called in that case. I thought an "abort chain" command was a good idea, but it doesn't work in the current design. The alternative is to relegate the "only-if-validation-passed" commands to their own sub-chain which only gets executed if validation passed.
So for now, I think the best strategy is a variant of LookupCommand which branches: perhaps generically implemented with a context key name to look up a boolean value and then configured with a "true" command, a "false" command, and perhaps a "null" command.
That one would be a lot tidier with the not-yet-released Chain functionality to specify a catalog/command pair with a single String. Is it time to roll a 1.0.1 (or 1.1.) commons-chain release? Is there anything else which should maybe go in it?
Joe
--
Joe Germuska [EMAIL PROTECTED] http://blog.germuska.com "Narrow minds are weapons made for mass destruction" -The Ex
--------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
