Interestingly, Digester already supports the expression replacement
mechanics (see org.apache.commons.digester.Substitutor), so it ought
to be really easy to do this kind of thing, and an elegant solution to
boot.
I'm +1 for it.
Craig
On Thu, 2 Dec 2004 16:40:31 -0600, Joe Germuska <[EMAIL PROTECTED]> wrote:
> In a discussion on the struts-user list, I got around to describing a
> configuration format which made me wonder if folks would tolerate
> some kind of expression evaluation engine in chain.
>
> The musing repeated below:
>
> At 1:57 PM -0600 12/2/04, Joe Germuska wrote:
> >I think you could find the view processor command by using the
> >standard Chain "lookup action". Well, out of the box, its "nameKey"
> >property would depend on some String value being placed into the
> >context under a certain key, and as it is now, we're talking about
> >using a String property of an Object in the context under a certain
> >key. If we gave the LookupCommand an expression language (JEXL,
> >perhaps?), then we could do something like this, which seems cool:
> >
> > <command
> > className="org.apache.commons.chain.generic.LookupCommand"
> > catalogName="struts-view-preprocess"
> > nameKey="${context.forward.name}"
> > optional="true"/>
> >
> >or possibly work some magic to make the "context" prefix assumed.
> >Anyone have an opinion about adding a JEXL dependency to Chain, or
> >whether this would be best left to a Struts subclass of
> >LookupCommand?
>
> Ideas? I'm not sure right now of the scope of this proposal -- is it
> just for the LookupCommand? Is it somehow implemented more widely?
> How can you do that when Chain is first-and-foremost an API?
>
> I can certainly see some of these questions leading folks to throw up
> their hands and say "let's just keep it simple." There's no critical
> reason to add this dependency to the core, but when you think about
> the expressive power it would provide in the config files, it seems
> pretty cool.
>
> 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]
>
>
---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
