mmh, after 13 years of OO, including 5 years Smalltalk, 6 years of Java and 2 years Apple WebObjects I would be *really* amazed if you could prove I have a problem discerning objects from classes. I think, with MB we are finally getting there. I'll be answering his mail in a few moments. This is really an amazing list.
----- Original Message ----- From: "kyle dawkins" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Thursday, December 19, 2002 7:41 PM Subject: Re: [Tapestry-developer] component definitions > Hey, I'm chiming in late here, but this discussion seems like we're > smacking our heads against a brick wall a little bit. I think this > whole confusion is kind of related to the problem that lots of > developers have understanding the difference between "Class" and > "Instance". Christian wants to put an *instance* of a component on > lots of pages, and doesn't seem to get that he needs to (to borrow the > OO term) *instantiate* it. In Java, you need to instantiate objects > that you want to use, or you create static methods that do it for you. > If you want a singleton for example, you still need to instantiate it > once, and you need to do that work yourself. This is no different to > how you set up your pages in Tapestry (or WebObjects, of course), > except it's not classes we're talking about, it's components. > > If you want an instance of your calendar object on a whole slew of > different pages, create a component that needs no parameters and > displays your component with all of its parameters set the way you like > them, and then put *that* component on all your pages. You get your > calendar all nicely configured and it doesn't take a bunch of lines in > your .jwc files, as described by MindBridge below. > > Or is that still too hard? > > Kyle Dawkins > Central Park Software > > On Thursday, Dec 19, 2002, at 12:27 US/Eastern, Mind Bridge wrote: > > > Hi Christian, > > > > I think am clear as to what you suggest (see below for an example). > > Here is > > an example of what I am talking about: > > > >>> New Component (Tapestry 2.4): > >>> ----------------------------- > >>> 1 x defining a new component > >>> 5 lines + 'component configuration', 1 line template, 1 line alias > >>> > >>> N x using the new component > >>> 1 line in template > > > >> huh? Sorry I really cannot follow. What are those 5 lines? > > > > JWC: > > ---- > > <?xml version="1.0" encoding="UTF-8"?> > > <!DOCTYPE component-specification PUBLIC "-//Howard Lewis > > Ship//Tapestry > > Specification 1.3//EN" > > "http://tapestry.sf.net/dtd/Tapestry_1_3.dtd";> > > <component-specification class="net.sf.tapestry.BaseComponent"> > > > > <!-- begin component configuration --> > > <component id="compId" type="SomeComponentThatNeedsToBeConfigured"> > > <binding name="someParameter1" expression="some value 1"/> > > <binding name="someParameter2" expression="some value 2"/> > > </component> > > <!-- end component configuration --> > > > > </component-specification> > > > > Template: > > --------- > > <span jwcid="compId"/> > > > > App spec: > > --------- > > <component-alias type="ConfiguredComponent" specification-path="..."/> > > > > Using the new component in every relevant page (same effect as what you > > suggest): > > ----------------------------------------------------------------------- > > - > > <span jwcid="@ConfiguredComponent"/> > > > > > > > >> What is "? lines + 'component configuration'"? > > > > What you suggest is to put the following block in the App spec instead: > > > > <!-- begin component configuration --> > > <component id="compId" type="SomeComponentThatNeedsToBeConfigured"> > > <binding name="someParameter1" expression="some value 1"/> > > <binding name="someParameter2" expression="some value 2"/> > > </component> > > <!-- end component configuration --> > > > > and make it possible for that component to be used in all application > > pages > > and components in the following way: > > > > <span jwcid="compId"/> > > > > > > As you can see, the difference between the above approaches is > > precisely 7 > > lines in the locations that I have specified. I have put the '? lines' > > because it is possible that additional code may be needed, although it > > is > > not apparent that it is at this point. > > > > Note that there is basically no difference between the two approaches > > when > > 'use' is concerned -- they both require one short line. > > > > > > I have to go out in about -5 minutes, so just a few quick final > > remarks for > > now: > > > >> 1. make type aliases optional (tapestry 2.4?) > > > > This is where we come from, actually. In the pre-2.2 world aliases were > > optional and Spindle, for example, did not use them at all. This is > > not very > > compatible with the notion of libraries, however. Please have a look > > at the > > mailing list archives on this topic, or perhaps Howard can explain his > > point > > of view. > > > > > > I hope this makes things clearer. > > > > You proposal is definitely interesting, but I think the 'composing > > component' one described above is very close. > > > > Best regards, > > -mb > > > > > > > > > > > > ------------------------------------------------------- > > This SF.NET email is sponsored by: Geek Gift Procrastinating? > > Get the perfect geek gift now! Before the Holidays pass you by. > > T H I N K G E E K . C O M http://www.thinkgeek.com/sf/ > > _______________________________________________ > > Tapestry-developer mailing list > > [EMAIL PROTECTED] > > https://lists.sourceforge.net/lists/listinfo/tapestry-developer > > > > > > ------------------------------------------------------- > This SF.NET email is sponsored by: Geek Gift Procrastinating? > Get the perfect geek gift now! Before the Holidays pass you by. > T H I N K G E E K . 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