Wicket依赖注入 [英] Wicket Dependency Injection

问题描述

我在Wicket中有一个带有表单的页面，其中表单需要协作者完成其工作。合作者注入（我正在使用Guice），看起来像：

I've got a page with a form in Wicket where the form requires a collaborator to get its job done. The collaborator is injected (for which I'm using Guice) and looks something like:

public class RegistrationPage extends WebPage {
    @Inject
    public RegistrationPage(RegistrationService service) {
        this.service = service;
        add(new RegistrationForm());            
    }

    private class RegistrationForm extends Form {
        public RegistrationForm() {
            // setup
        }

        protected void onSubmit() {
           service.doSomething();
        }
    }
}

我不喜欢想法只是在需要它的RegistrationForm时将RegistrationService注入到RegistrationPage中。我可以更改RegistrationForm以接收RegistrationService：

I don't like the idea that the RegistrationService is injected into the RegistrationPage when it's just the RegistrationForm that needs it. I could change the RegistrationForm to receive the RegistrationService:

public RegistrationForm(RegistrationService service) {
    this.service = service;
}

并从RegistrationPage中删除该字段，但RegistrationPage仍在使用做传递。

and remove the field from the RegistrationPage, but the RegistrationPage is still being used to do the pass-through.

我想我问的是这样做的最佳做法是什么？这样做是否可行，或者将RegistrationForm注入页面可能更好：

I guess what I'm asking is what the best-practise is for doing this? Is this ok to do, or would it perhaps be better to inject the RegistrationForm itself into the Page:

   public class RegistrationPage extends WebPage {
        @Inject
        public RegistrationPage(RegistrationForm form) {
            add(form);
        }
   }

   ---

   private class RegistrationForm extends Form {
        private RegistrationService service;

        @Inject
        public RegistrationForm(RegistrationService service) {
            this.service = service;
        }

        protected void onSubmit() {
           service.doSomething();
        }
    }

我更喜欢这个，因为我想将RegistrationForm放在一个单独的类/文件中。我对Wicket很陌生，所以不确定规范是什么 - 有人能告诉我引导光吗？ ：）

I'd prefer this as I'd like to have the RegistrationForm in a separate class/file. I'm quite new to Wicket so unsure of what the norm is - can someone show me the guiding light? :)

推荐答案

wicket + ioc的基本范例是：大多数依赖项应该通过setter注入注入。 WebPages是不可能构造函数注入的。

the basic paradigm with wicket+ioc is: most dependencies should be injected via setter injection. constructor injection is impossible for WebPages.

组件/面板/表单/页面应仅在接收端。

components/panels/forms/pages should only be on the recieving end.

所以，将依赖项 RegistrationService 快乐地注入 RegistrationForm ，然后在RegistrationPage中使用add（new）创建它RegistrationForm（））;

so, inject the dependency to RegistrationService happily into the RegistrationForm , then create it in the RegistrationPage with add(new RegistrationForm());

wicket有IComponentInstantiationListener - 其中一个是guice。他们会在每个组件/网页的构造函数中得到通知。因此，您的RegistrationForm将在您的代码的任何部分可以执行之前注入其依赖项。

wicket has IComponentInstantiationListener - one of them is guice. they get notified during the constructor of each component/webpage. so your RegistrationForm will have its dependencies injected before any part of your code can execute.

我的方式：
（当然RegistrationForm可以在另一个文件）

the way i would do it: (of course RegistrationForm can be in another file)

public class RegistrationPage extends WebPage {

@Inject
public RegistrationPage() {
    add(new RegistrationForm());            
}

---
private static class RegistrationForm extends Form {
   RegistrationService service;

      @Inject
     public void setRegistrationService (RegistrationService  service){
     this.service = service;
        }
    public RegistrationForm() {
        // setup
    }

    protected void onSubmit() {
       service.doSomething();
    }
}
}

如果您决定放入RegisterForm里面的Page作为内部类，记得把它声明为静态！你很可能不需要任何对封闭类的引用。

if you decide to put the RegistrationForm inside the Page as inner class, remember to declare it static! you will most likely not need any references to the enclosing class.

这篇关于Wicket依赖注入的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！