I provided a couple of thoughts below with [[[ -----Original Message----- From: Dirk Möbius [mailto:[email protected]] Sent: Thursday, June 10, 2010 3:30 AM To: [email protected] Subject: RE: Component names inside the containers
aappddeevv <[email protected]> wrote: > We'll after looking this over I'm not sure that this implements my thinking > although I believe that I understand Dirk's comments now. I think I saw: > > a) The IDProperty annotation indicates which property the id/name should be > placed into. > b) The default for a Component is "name" but it could be overridden of > course with the annotation on a subclass. > > I am not sure that overriding the property that sets the id is useful in > practice. You're right, _overriding_ the property is not useful, and although you can do that you shouldn't do it. The annotation is for _defining_ the property without enforcing a certain name, as you would do with an interface. See my explanation below. [[[[Yes, however using the name property has no interface either. But I get your point. > The reason why this is different than BeanNameAware is that BeanNameAware > always set the property "beanName" so it always goes through the same > property/setter interface. Clients then propagate the name to anywhere they > want underneath which as far as I ever seen, most clients set the bean name > to a property "name." If you want the equivalent of the BeanNameAware, > without any extra annotations, just use the "name" property. By using the > idproperty annotation, you are actually changing the property that the name > is set through...very different than BeanNameAware. > > As for invasiveness, since the "id/name" property must be defined at the > Component level, which is fairly high up in the wtx hierarchy. The > invasiveness concept is less a concern than with pojo objects that have no > common class hierarchy--where I would agree it is more of a concern and pojo > invasiveness is more of an issue. Note that WtkxSerializer is not only meant for creating Component trees. You can create _any_ pojos. You can see WtkxSerializer as a configuration tool, similar to the deserialization part of XMLBeans or SimpleXML (http://simple.sf.net). WtkxSerializer has been carefully crafted without any references to wtk classes. In fact, the name "Wtkx" is misleading, that's why it gets renamed to BeanSerializer and moved to another package in the next release. So, the fact that WtkxSerializer/BeanSerializer populates any pojo, calls for a more flexible solution to inject the id into an arbitrary pojo. Maybe your pojo already contains either an 'id' property or a 'name' property, why should Pivot impose the other one on it? [[[I hear you on this. In fact, you can consider the serializer to almost be a DI-container, however, its not. I can send you my spring serializer extension that allows all objects in the serializer to participate in full DI creation and initialization semantics if you want. That was the point of doing a very small change request to the serializer. This allows me, while not making the serializer significantly different, to automatically create a spring application context based off the pivot component class name, use full DI semantics to initialize the pivot component and then start it doing "something" as its added back into the component tree. You could use the serializer extension to also have finalization semantics implemented but I had not thought about object lifecycle enough yet. In the case of the serializer and creation and initialization semantics, we'll probably have to define a few well thought-out APIs that allow stronger contracts and more communication between components for creation, initialization, tree construction and tree deconstruction. For example, I can easily create a full style defaulting system if I can just receive a notification about component adds/removes across the component tree (and not just across the superclass tree). > Also, to make this useful, you need to > guarantee there is a "get" property to get the id value. The idproperty > annotation does not guarantee this in a subclass override--in other words, > external processing operations cannot rely on being able to get the name and > this makes processing ill-specified. I see. But I think the evil doer here is the developer who overrides Component and changes the @IdProperty annotation. I think it is sufficient to document clearly that overriding the @IdProperty annotation is an evil thing. Note that WtkxSerializer would also need a setter. I admit it's a unfortunate situation if the @IdProperty annotation is there but the setter is missing and no one enforces it. But WtkxSerializer can fail fast in this case so the developer would notice it soon. I guess that by now you realized that I'm more on the pragmatic side of development -- or rather, I'm all for freedom, not for restrictions. I don't like a framework to be too restrictive (eg. all things private/package private/protected etc.). I think we're all adults who know what to do when we realize the intention of a framework. But that's just my personal opinion. I make my suggestions here, but the decision is of course up to the Pivot developers. I'm not a Pivot team member. [[[I've noticed that about your recommendations. I think you have alot of good ideas and I believe your intent is all in the right direction. I myself think that solid engineering backing simplistic API makes pivot a huge winner. That's why I always push for the strategy design pattern to be used, for extensibility without subclasses, etc. All this makes for solid engineering that allows API creation that is simplistic for people like me. That being said, I would not break down in tears if Pivot goes for the BeanNameAware interface route. It would be a great improvement anyway if the id can be injected into the pojos by any means. [[[I would not frame it as annotation versus BeanNameAware. I think That with using "name", there is no interface as well. But I get your point and I am not hard and fast on it as long as we can write a tree walker and make it easier for everyone to walk by id. Which, with a pivot official "tree walker by id" utils method, works fine for me. Regards, Dirk. > -----Original Message----- > From: Greg Brown [mailto:[email protected]] > Sent: Wednesday, June 09, 2010 10:56 AM > To: [email protected] > Cc: [email protected] > Subject: Re: Component names inside the containers > > I have prototyped this change - see attached patch. Let me know if this is > consistent with what you are envisioning. I added a static findAnnotation() > method to BeanAdapter. WTKXSerializer uses this method to locate an > IDProperty annotation and, if present, uses the value to set the given > property. > > Note that we may not be able to apply this change to Pivot 1.5.1. Adding the > name property requires a change to the ComponentListener interface, which > would break backwards compatibility. We could potentially add the ID > annotation handling to 1.5.1, though. > > G
