Therefore, we absolutely shouldn't have an expression parser, because
that would basically defeat the purpose. In the case of switching to a
JSR EL, but not using its native syntax, we lose the benefits an IDE can
give us by providing autocompletion and other assistance with
expressions.
Don
Alexandru Popescu wrote:
> On 9/29/06, tm jee <[EMAIL PROTECTED]> wrote:
>> 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.
>>
>
> This would be indeed a possible drawback, not to mention the confusion
> that will arise from the forum posts:
>
> [future-quote]
> Q: I have the following in my JSP and it is not working:
>
> <ww:property value="$tralala" />
>
> A: Oh no, you need to write it ${tralala}
>
> A: No, that's not true: you need to write it %{tralala}
>
> A: by the way what expression language are you using?
> [/future-quote]
>
>> 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?
>>
>
> AFAIR, considering that the expressions are already cached (which
> represents an improvement on the performance), the next problem is the
> value manipulation which is not so performant (though I haven't looked
> so deep to suggest some optimizations)
>
> ./alex
> --
> .w( the_mindstorm )p.
>
>> 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]
>>
>>
>>
>>
>>
>>
>>
>
> ---------------------------------------------------------------------
> 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]
