commons-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Joe Germuska <>
Subject Re: [chain] LookupCommand's return value
Date Wed, 16 Feb 2005 14:20:32 GMT
At 8:08 AM -0500 2/16/05, Sean Schofield wrote:
>  > As it is now, there's no way to abort a looked-up chain without
>>  causing the base chain to also abort.  It seems like this would not
>>  always be the desired result.  [snip]
>Interesting way of thinking about it.  I still think the way
>LookupCommand works now should be the default behavior.
>-1 on changing that (which I don't think you are really proposing)

Not changing as in breaking, but perhaps extending.  What about a 
property "ignoreReturnValue" which would always return "false" 
instead of returning what the looked up command sought.

>>  I'm just hesitant to add a new dependency on my own whim.  JEXL isn't
>>  very heavy (132 K) but I think people are keen on keeping Chain light
>>  too.
>Keeping chain light would be nice.  I don't know too much about JEXL
>personally although I will be investigating it shortly as an
>alternative to Velocity for some template stuff I have.  How would you
>propose doing it if you didn't use JEXL?

Well, I have zero interest in developing any other expression parser, 
so from there, I think you're limited to very crude things, like a 
bunch of properties on a command that would specify context keys and 
imply handling, like 'abortIfContextValueTrueOrNull'

Basically, the JEXL dependency would only be a runtime dependency for 
people who chose to use those implementations of commands which 
depended upon it.  We could have a subproject for "contrib" or 
something, but my feeling is that that's more trouble than its worth. 
If the binary JAR for commons-chain is readily available and the API 
has no dependencies, then why not include useful implementations in 
the same JAR with clear instructions on when they require auxiliary 
libraries?  Still, if people would prefer a commons-chain-contrib 
project, I wouldn't complain; I'd just want some opinions on where 
exactly to put it.


Joe Germuska       
"Narrow minds are weapons made for mass destruction"  -The Ex

To unsubscribe, e-mail:
For additional commands, e-mail:

View raw message