Yes, keeping it separate makes sense to me. Let me explain my interest in this area. At joda.org (and for my day job) I have been developing classes to manage domain models. Part of this work has involved defining classes that provide bean meta data, similar to DynaClass and PropertyDescriptor and bean property access. Also built is code to query the object model using XPath backed by Jaxen. On my todo list was an implementation of the JEL syntax. I hadn't decided if that should be done as a plugin to Jaxen, or from scratch.
So two things are in my mind. 1) Can I reuse the (forthcoming) JEL implementation from commons? 2) Could the joda work potentially form the basis for the new commons component that James describes? Stephen From: Craig R. McClanahan <[EMAIL PROTECTED]> > I agree with keeping expression evaluation separate from DynaBeans. Not > only does this provide for consistency (what method on a standard JavaBean > knows how to interpret "one.two[3].four(5)" :-), but different > applications might want to use different expression language syntaxes -- > and baking a particular one into the beans themselves would really hamper > this. > > Craig > > > On Thu, 18 Apr 2002, James Strachan wrote: > > > Date: Thu, 18 Apr 2002 13:07:56 +0100 > > From: James Strachan <[EMAIL PROTECTED]> > > Reply-To: Jakarta Commons Developers List <[EMAIL PROTECTED]> > > To: Jakarta Commons Developers List <[EMAIL PROTECTED]> > > Subject: Re: [BeanUtils] PropertyUtils and DynaBeans > > (getPropertyDescriptors) > > > > From: "James Strachan" <[EMAIL PROTECTED]> > > > ----- Original Message ----- > > > From: "Stephen Colebourne" <[EMAIL PROTECTED]> > > > > This is what I was getting at. If DynaBeans were to become used as the > > > main > > > > interface (instead of PropertyUtils), then DynaBeans would need to > > support > > > > this notation. > > > > > > I think DynaBeans is a great abstraction for DynaBeans and regular beans. > > > DynaBeans can handle > > > > > > * regular properties via get(String name) > > > * indexed properties via get(String name, int index); > > > * mapped properties via get(String name, String key); > > > > > > Where DynaBeans are maybe not the best abstraction right now is for > > complex > > > expressions like one.two[3].four(5). > > > > Incidentally, there's an expression language I refer to as JEL (Java > > Expression Language) - I'm hoping the name catches on like JSTL did ;-). Its > > used in JSTL, will be native in JSP soon and I think JSF uses it too. Its > > quite similar to a superset of the expression language currently supported > > by beanutils. Right now it exists in the JSTL reference implementation over > > at jakarta-taglibs in the 'standard' taglib and hopefully its gonna move > > over to jakarta commons sometime soon. > > > > When JEL moves over here, we're gonna have a seperate commons component for > > parsing and evaluating complex expressions on beans, Maps, Lists, arrays > > (and hopefully DynaBeans too). So maybe its a good idea to consider > > expression languages as being logically seperate from an 'introspection > > wrapper'. i.e. that DynaBeans can be used as a great wrapper around > > introspection while supporting new features like mapped properties and > > DynaBeans themselves too and that expression languages should be used > > seperately, either via the API in beanutils right now or the JEL which will > > arrive here later. > > > > Does that sound a reasonable strategy? > > > > James -- To unsubscribe, e-mail: <mailto:[EMAIL PROTECTED]> For additional commands, e-mail: <mailto:[EMAIL PROTECTED]>
