Well, you were the one who said that if I created the unbound model (from(A.class)) then I could bind it to a plain IModel, without the extra type information :)
I just assumed that it would keep the 'A.class' information passed in the beginning and use it at runtime. It seems that the Evaluation holds the initial 'from' type, but it isn't passed down to LazyModel when it is created (it only receives target and stack), so it has to try to discover the type by itself, and fails. I'll try to do some experiments here... On Thu, Jun 13, 2013 at 6:21 PM, Sven Meier <[email protected]> wrote: > Well, here again LazyModel needs the type of the bound target at runtime. > Without any runtime information about the model's object type, LazyModel > cannot derive the type of the evaluation result. > > Sven > > > On 06/13/2013 10:55 PM, tetsuo wrote: > >> this test also passes here, but >> >> assertEquals(B.class, ((IObjectClassAwareModel<B>) >> model.bind(a)).getObjectClass(**)); >> >> assertEquals(B.class, ((IObjectClassAwareModel<B>) >> model.bind(Model.of(a))).**getObjectClass()); >> >> >> While the first assert passes, but the second one doesn't. >> >> The exception is thrown not when getting the object, but the object class >> (the AbstractTextComponent class calls this before rendering and while >> converting input). >> >> >> >> >> >> On Thu, Jun 13, 2013 at 5:40 PM, Sven Meier <[email protected]> wrote: >> >> Strange, works fine here: >>> >>> @Test >>> public void bindToModelAndGet() { >>> LazyModel<B> model = model(from(A.class).getB()); >>> >>> final A a = new A(); >>> a.b = new B(); >>> >>> assertEquals(a.b, model.bind(Model.of(a)).****getObject()); >>> >>> } >>> >>> Sven >>> >>> >>> On 06/13/2013 10:23 PM, tetsuo wrote: >>> >>> Thanks for the response! >>>> >>>> If I use an object instance, it works, but if I do as your third example >>>> (create a model from the class, then bind to a >>>> non-IObjectClassAwareModel-****model), >>>> >>>> it doesn't: >>>> >>>> public class TestPage extends WebPage { >>>> >>>> private String text; >>>> >>>> public TestPage(final PageParameters parameters) { >>>> >>>> super(parameters); >>>> >>>> add(new Form<Void>("form") >>>> >>>> .add(new TextField<String>("text", >>>> model(from(TestPage.class >>>> ).getText()).bind(Model.of(****this))))); >>>> >>>> >>>> } >>>> >>>> public String getText() { return text; } >>>> >>>> public void setText(String text) { this.text = text; } >>>> >>>> } >>>> >>>> >>>> If I change 'Model.of(this)' to 'this' or an IObjectClassAwareModel >>>> implementation, it works: >>>> >>>> >>>> class TestPageModel extends AbstractReadOnlyModel<****TestPage> >>>> >>>> implements IObjectClassAwareModel<****TestPage> { >>>> >>>> >>>> public TestPage getObject() { return TestPage.this; } >>>> >>>> public Class<TestPage> getObjectClass() { return >>>> TestPage.class; >>>> } >>>> >>>> } >>>> >>>> >>>> Is this a bug? I could create some wrapper models to make it work, but >>>> if >>>> this is a bug, I'd prefer to wait for a corrected version. >>>> >>>> >>>> Thanks again >>>> >>>> >>>> On Thu, Jun 13, 2013 at 4:52 PM, Sven Meier <[email protected]> wrote: >>>> >>>> Hi, >>>> >>>>> LazyModel needs to know the type of the model object to return an >>>>> appropriate proxy: >>>>> >>>>> model(from(a).getB()); // works >>>>> model(from(aModel).getB()); // aModel must be an >>>>> IObjectClassAwareModel >>>>> model(from(A.class).getB()).******bind(aModel); // works even if >>>>> aModel >>>>> >>>>> >>>>> does not reveal its object class >>>>> >>>>> Sven >>>>> >>>>> >>>>> On 06/13/2013 09:35 PM, tetsuo wrote: >>>>> >>>>> wait, wait, do you actually do something like >>>>> >>>>>> new TextField<String>("name", new IModel<String>(){ >>>>>> public String getObject() { >>>>>> return entity.getName(); >>>>>> } >>>>>> public void setObject(String value) { >>>>>> entity.setName(value); >>>>>> } >>>>>> public void detach(){} >>>>>> }); >>>>>> >>>>>> for every single field in your system, or you use LazyModel? >>>>>> >>>>>> Well, I've been trying to use LazyModel, but with it I have to pass >>>>>> the >>>>>> type of every field (the last arg of TextField's constructor) because >>>>>> if I >>>>>> don't, this exception is thrown: >>>>>> >>>>>> Caused by: java.lang.******IllegalArgumentException: T is not a >>>>>> class or >>>>>> parameterizedType >>>>>> >>>>>> at org.wicketstuff.lazymodel.******reflect.Generics.getClass(** >>>>>> Generics.java:78) >>>>>> >>>>>> at org.wicketstuff.lazymodel.******LazyModel.getObjectType(** >>>>>> LazyModel.java:139) >>>>>> >>>>>> at org.wicketstuff.lazymodel.******LazyModel.getObjectClass(** >>>>>> LazyModel.java:124) >>>>>> >>>>>> at org.apache.wicket.markup.html.******form.** >>>>>> AbstractTextComponent.**** >>>>>> getModelType( >>>>>> AbstractTextComponent.java:******167) >>>>>> >>>>>> at org.apache.wicket.markup.html.******form.** >>>>>> AbstractTextComponent.**** >>>>>> resolveType( >>>>>> AbstractTextComponent.java:******152) >>>>>> >>>>>> at org.apache.wicket.markup.html.******form.** >>>>>> AbstractTextComponent.**** >>>>>> onBeforeRender( >>>>>> AbstractTextComponent.java:******142) >>>>>> >>>>>> >>>>>> >>>>>> Any thoughts? >>>>>> >>>>>> I guess I'll just go back to CompoundPropertyModel... (sigh) >>>>>> >>>>>> >>>>>> (and no, I don't spend that much time debugging property models. I >>>>>> usually >>>>>> don't rename properties that often, and when I have to do some >>>>>> refactoring, >>>>>> usually the structure changes, and I have to revise all pages >>>>>> anyway...) >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> On Fri, May 31, 2013 at 10:49 AM, Martin Grigorov < >>>>>> [email protected] >>>>>> >>>>>> wrote: >>>>>>> >>>>>>> On Fri, May 31, 2013 at 4:24 PM, tetsuo <[email protected] >>>>>> > >>>>>> wrote: >>>>>> >>>>>> Black magic, or code generation? hard choice... :) >>>>>>> >>>>>>> I think I'll try the black magic, let's see how it goes :) >>>>>>>> >>>>>>>> I personally prefer writing the boilerplate of custom Model per >>>>>>>> field. >>>>>>>> >>>>>>>> It is a boring work but it gives me: >>>>>>> * type safety >>>>>>> * the fastest read/write access possible >>>>>>> * easier debugging >>>>>>> >>>>>>> (who knows - maybe I've spent less time to write such models than >>>>>>> you've >>>>>>> spent to debug your issues with property model after refactoring) >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> On Thu, May 30, 2013 at 8:16 PM, Igor Vaynberg < >>>>>>> >>>>>>>> [email protected] >>>>>>>> >>>>>>>> wrote: >>>>>>>> >>>>>>>>> On Thu, May 30, 2013 at 12:37 PM, tetsuo <[email protected]> >>>>>>>>> >>>>>>>>> wrote: >>>>>>>>> >>>>>>>> -1000! >>>>>>>> >>>>>>>>> This will be horrible! Even with the current API, most generics I >>>>>>>>>> >>>>>>>>>> have >>>>>>>>>> >>>>>>>>> to >>>>>>>> >>>>>>>> declare in my code don't add anything to type safety. For example: >>>>>>>> >>>>>>>>> while i am also not a fan of having component generified i do >>>>>>>>> believe >>>>>>>>> the example below is a bit contrived. >>>>>>>>> >>>>>>>>> first, i hope most people do not use PropertyModels because they >>>>>>>>> are >>>>>>>>> not compile-time-safe. there are plenty of project that implement >>>>>>>>> compile-time-safe models, personally i prefer >>>>>>>>> https://github.com/42Lines/******metagen<https://github.com/42Lines/****metagen> >>>>>>>>> <https://github.com/**42Lines/**metagen<https://github.com/42Lines/**metagen> >>>>>>>>> > >>>>>>>>> <https://github.com/**42Lines/**metagen<https://github.com/**42Lines/metagen> >>>>>>>>> <https://github.com/**42Lines/metagen<https://github.com/42Lines/metagen> >>>>>>>>> >>to >>>>>>>>> >>>>>>>>> using proxy-based solutions. >>>>>>>>> >>>>>>>>> >>>>>>>>> further, i hope even less people use compound property models. they >>>>>>>>> are even more unsafe then property models and make your code even >>>>>>>>> more >>>>>>>>> fragile. i would hate to refactor code that uses CPMs. >>>>>>>>> >>>>>>>>> add(new Form<Person>("form", new >>>>>>>>> CompoundPropertyModel<Person>( >>>>>>>>> **** >>>>>>>>> >>>>>>>>> new >>>>>>>>> >>>>>>>>>> PropertyModel<Person>(this, "person"))) >>>>>>>>>> .add(new TextField<String>("name")) >>>>>>>>>> .add(new TextField<Integer>("age")) >>>>>>>>>> .add(new TextField<Double>("salary")) >>>>>>>>>> .add(new Button("save", new >>>>>>>>>> >>>>>>>>>> PropertyModel<Person>(this,"******person")){ >>>>>>>>>> >>>>>>>>> public void onSubmit() { >>>>>>>>> >>>>>>>>> repository.save((Person)******getForm().**** >>>>>>>>>> getDefaultModelObject()); >>>>>>>>>> >>>>>>>>>> } >>>>>>>>> }); >>>>>>>>> >>>>>>>>>> In my experience, this kind of code is fairly common in Wicket >>>>>>>>>> applications. Every form component must be declared with a type, >>>>>>>>>> but >>>>>>>>>> >>>>>>>>>> none >>>>>>>>>> >>>>>>>>> has *any* kind of type safety gain. >>>>>>>>> but how often do you declare a form component without adding any >>>>>>>>> validators to it? the generic type of component also makes sure you >>>>>>>>> add the correct validator. for example it wont let you add a >>>>>>>>> validator >>>>>>>>> that expects strings to a component that produces integers. >>>>>>>>> >>>>>>>>> also, not sure why you are replicating the model in Button. first, >>>>>>>>> the >>>>>>>>> Button uses its model to fill its label; secondly, in real code the >>>>>>>>> model would be in a final var or field that things like onsubmit >>>>>>>>> can >>>>>>>>> access easily. >>>>>>>>> >>>>>>>>> -igor >>>>>>>>> >>>>>>>>> >>>>>>>>> - The property model uses reflection, so its type can't be >>>>>>>>> verified >>>>>>>>> by >>>>>>>>> >>>>>>>>> the >>>>>>>> >>>>>>>> compiler (this.person could be anything, not just a Person). >>>>>>>>> >>>>>>>>>> - Generics will guarantee that the form model will be of type >>>>>>>>>> Person, >>>>>>>>>> >>>>>>>>>> but >>>>>>>>>> >>>>>>>>> since it's all declared inline, and the real model isn't >>>>>>>>> verifiable, >>>>>>>>> it >>>>>>>>> >>>>>>>>> just adds lots of verbosity without any real gain. >>>>>>>> >>>>>>>> - Most form components use the implicit model, that also uses >>>>>>>>> >>>>>>>>>> reflection, >>>>>>>>>> >>>>>>>>> and also can't verify the actual type of the underlying property, >>>>>>>>> at >>>>>>>>> >>>>>>>>> compilation time. Even in runtime, *the type information is lost >>>>>>>>>> due >>>>>>>>>> >>>>>>>>>> erasure >>>>>>>>>> >>>>>>>>> *, so it can't use it to do any additional verification. >>>>>>>>> >>>>>>>>>> *- Worse, you can even declare the "name" TextField as <Integer> >>>>>>>>>> or >>>>>>>>>> <Double> (while maintaining the 'text' attribute as String), and >>>>>>>>>> >>>>>>>>>> since >>>>>>>>>> >>>>>>>>> there is no type information at runtime, it doesn't matter. It >>>>>>>> won't >>>>>>>> >>>>>>>> even >>>>>>>>> throw an exception (it will just work normally).* In this case, the >>>>>>>>> type >>>>>>>>> declaration is simply a lie. >>>>>>>>> >>>>>>>>> Just pain, no gain. In my code, I sometimes just add a >>>>>>>>>> >>>>>>>>>> @SuppressWarnings( >>>>>>>>>> >>>>>>>>> "rawtypes") to the class, and remove all useless generic type >>>>>>>>> declarations. >>>>>>>>> >>>>>>>>> If everything will be required to declare them, I will have do it >>>>>>>>> >>>>>>>>>> more >>>>>>>>>> >>>>>>>>> frequently. >>>>>>>> >>>>>>>> That said, repeater components benefit greatly from generics. So do >>>>>>>>> >>>>>>>>>> custom >>>>>>>>>> >>>>>>>>> models, validators, and converters. Or the rare cases that we >>>>>>>>> >>>>>>>>>> explicitly >>>>>>>>>> >>>>>>>>> declare the form component model. But forcing everything to be >>>>>>>>> >>>>>>>>> generic-typed will just make Wicket extremely verbose to use, with >>>>>>>>>> >>>>>>>>>> very >>>>>>>>>> >>>>>>>>> little benefit. >>>>>>>> >>>>>>>> >>>>>>>>>> On Thu, May 30, 2013 at 4:00 AM, Martin Grigorov < >>>>>>>>>> >>>>>>>>>> [email protected] >>>>>>>>>> >>>>>>>>> wrote: >>>>>>>> >>>>>>>> Hi, >>>>>>>>> >>>>>>>>>> I just pushed some initial work for [1] and [2] in >>>>>>>>>>> branch generified-component-4930. >>>>>>>>>>> >>>>>>>>>>> So far it doesn't look nice. >>>>>>>>>>> >>>>>>>>>>> The added generics break somehow setMetaData/getMetaData methods >>>>>>>>>>> - >>>>>>>>>>> >>>>>>>>>>> you >>>>>>>>>>> >>>>>>>>>> can >>>>>>>>> see compilation errors in Component and Page classes. I think it is >>>>>>>>> >>>>>>>>>> caused >>>>>>>>>> by the anonymous instance of MetaDataKey ( new >>>>>>>>>> MetaDataKey<T>(type) >>>>>>>>>> {} >>>>>>>>>> >>>>>>>>>> ). >>>>>>>>> Also the visit*** methods do not compile at the moment, but even if >>>>>>>>> >>>>>>>>>> we >>>>>>>>>> >>>>>>>>>> find >>>>>>>>> a way to fix their signature I think writing a visitor will become >>>>>>>>> >>>>>>>>>> quite >>>>>>>>>> >>>>>>>>>> cumbersome. >>>>>>>>> >>>>>>>>> At the moment we have IVisitor >>>>>>>>>> >>>>>>>>>>> and org.apache.wicket.util.******iterator.**** >>>>>>>>>>> AbstractHierarchyIterator >>>>>>>>>>> which >>>>>>>>>>> >>>>>>>>>>> do >>>>>>>>>>> >>>>>>>>>> the >>>>>>>>> same job. The Iterator API is supposed to be simpler to write for >>>>>>>>> >>>>>>>>>> the >>>>>>>>>> >>>>>>>>>> users. Maybe we can drop IVisitor ... ?! >>>>>>>>> I'd like to ask for help with this task. It is supposed to be the >>>>>>>>> >>>>>>>>>> biggest >>>>>>>>>>> >>>>>>>>>> API break for Wicket 7.0. My current feeling is that the end >>>>>>>>>> result >>>>>>>>>> won't >>>>>>>>>> be very pleasant for the user-land code. >>>>>>>>>> >>>>>>>>>> For example the application code will have to do something like: >>>>>>>>>>> >>>>>>>>>>> WebMarkupContainer<Void> wmc = new >>>>>>>>>>> WebMarkupContainer<>("id") >>>>>>>>>>> >>>>>>>>>>> It is not that much but we have to decide whether we want it. >>>>>>>>>>> But first let's try to fix the compilation problems. >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> 1. >>>>>>>>>>> https://issues.apache.org/******jira/browse/WICKET-4930<https://issues.apache.org/****jira/browse/WICKET-4930> >>>>>>>>>>> <https:**//issues.apache.org/**jira/**browse/WICKET-4930<https://issues.apache.org/**jira/browse/WICKET-4930> >>>>>>>>>>> > >>>>>>>>>>> <https:**//issues.apache.org/**jira/**browse/WICKET-4930<http://issues.apache.org/jira/**browse/WICKET-4930> >>>>>>>>>>> <http**s://issues.apache.org/jira/**browse/WICKET-4930<https://issues.apache.org/jira/browse/WICKET-4930> >>>>>>>>>>> >>(Add >>>>>>>>>>> generics >>>>>>>>>>> >>>>>>>>>>> to >>>>>>>>>>> >>>>>>>>>> o.a.w.Component) >>>>>>>>> 2. >>>>>>>>> >>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> https://cwiki.apache.org/******confluence/display/WICKET/**<https://cwiki.apache.org/****confluence/display/WICKET/**> >>>>>>>>>>> <h**ttps://cwiki.apache.org/****confluence/display/WICKET/**<https://cwiki.apache.org/**confluence/display/WICKET/**> >>>>>>>>>>> > >>>>>>>>>>> >>>>>>>>>>> Wicket+7.0+Roadmap#Wicket7.******0Roadmap-Genericsfororg.** >>>>>>>>>> >>>>>>>>> apache.wicket.Component<https:****//cwiki.apache.org/** >>>>>>> confluence/** <http://cwiki.apache.org/confluence/**> >>>>>>> display/WICKET/Wicket+7.0+****Roadmap#Wicket7.0Roadmap-** >>>>>>> Genericsfororg.apache.wicket.****Component<https://cwiki.** >>>>>>> apache.org/confluence/display/**WICKET/Wicket+7.0+Roadmap#** >>>>>>> Wicket7.0Roadmap-**Genericsfororg.apache.wicket.**Component<https://cwiki.apache.org/confluence/display/WICKET/Wicket+7.0+Roadmap#Wicket7.0Roadmap-Genericsfororg.apache.wicket.Component> >>>>>>> > >>>>>>> >>>>>>> >
