Its doable I guess. If we have an Expression parser / converter like Alex pointed out, we could have a standard syntax, but it would be more complicated to implement. Without an Expression parser / converter, it'd likely to get users confused as it depends on what implementation is being used. Either case, I think we should stick with a standard supported implementation i guess. Personally, I think that Ognl is still the most powerfull expression language. :-) Btw, is Ognl so slow? I think there's some caching done to the expression evaluation, is that not sufficient to make the performance acceptable as well? rgds
----- Original Message ---- From: Alexandru Popescu <[EMAIL PROTECTED]> To: Struts Developers List <dev@struts.apache.org> Sent: Friday, 29 September, 2006 3:38:45 PM Subject: Re: Abstracting Ognl from XWork and Struts 2? On 9/29/06, Don Brown <[EMAIL PROTECTED]> wrote: > I've been toying with this idea of severing XWork and Struts 2's strict > dependency to OGNL. The goal is not necessary to remove OGNL outright, > but to make it possible to replace it with another expression language. > I'm happy with OGNL right now, however a couple things - its slow, > mostly unsupported, doesn't have tool support, and did I mention slow? - > inspire me to want to start to wean Struts off of it. > > How would we do it? > 1. Pull out a ValueStack interface from OgnlValueStack > 2. Create an abstract factory, ValueStackFactory, to create the ValueStack > 3. Pull out an interface from OgnlUtils and create a factory for it > 4. Replace/abstract the custom type conversion stuff > > I've done 1 and 2, compiling and tests passing. #3 seems pretty easy, > but the big question mark is #4. Also, I'd imagine things like our tags > are tied to the OGNL grammer, which might be interesting. > > Again, my goal isn't to remove it completely, but just to make it > possible to swap it out sometime in the future with JEXL, JSP EL, custom > OGNL (like Wicket and Stripes have done), WW 1 EL, or BeanUtils EL. The > last two might be interesting to assist in migration situations. > > What does some of the Webwork veterans think? Is this doable? > IMO, this is doable. But I think it may require yet another abstraction: an expression converter, as the engines you are mentioning are using different types of syntax. Or, if this is something that comes in the XValueStack implementation than I guess it may work too. ./alex -- .w( the_mindstorm )p. > Don > > --------------------------------------------------------------------- > 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]
