来自 Form 类的方法 form(Class<T>) 在 Play 中已弃用！框架 [英] The method form(Class&lt;T&gt;) from Form class is deprecated in Play! Framework

问题描述

我花了很多时间试图解决这个问题，并寻找替代方法，但没有成功.

I spent a lot of time trying so solve this problem, and searching the method to substitute this one, without success.

首先，玩！我有义务使用和注入 FormFactory(在 https://www.playframework.com/documentation/2.5.0/JavaForms).

First, Play! obligates me to use and inject the FormFactory (that is explained in https://www.playframework.com/documentation/2.5.0/JavaForms).

但只是为了实例化这个 FormFactory，我必须为它的构造函数传递 3 个参数，即 MessagesApi、Formatters 和 Validator.包括，我必须实例化 Validator 接口，但我不确定这样做是否正确.

But just for instantiate this FormFactory I had to pass 3 parameters for it's constructor, that is MessagesApi, Formatters and Validator. Including, I had to instantiate the Validator interface, and I'm no sure that is the right way to do it.

为了更简单，我把它放在另一个类中:

To make it more easy, I separated it in another class:

    package controllers;

    import java.util.Set;
    import javax.validation.ConstraintViolation;
    import javax.validation.Validator;
    import javax.validation.executable.ExecutableValidator;
    import javax.validation.metadata.BeanDescriptor;
    import play.data.FormFactory;
    import play.data.format.Formatters;
    import play.i18n.MessagesApi;

    class Validador implements Validator {

    @Override
    public ExecutableValidator forExecutables() {
        // TODO Auto-generated method stub
        return null;
    }

    @Override
    public BeanDescriptor getConstraintsForClass(Class<?> arg0) {
        // TODO Auto-generated method stub
        return null;
    }

    @Override
    public <T> T unwrap(Class<T> arg0) {
        // TODO Auto-generated method stub
        return null;
    }

    @Override
    public <T> Set<ConstraintViolation<T>> validate(T arg0, Class<?>... arg1) {
        // TODO Auto-generated method stub
        return null;
    }

    @Override
    public <T> Set<ConstraintViolation<T>> validateProperty(T arg0, String arg1, Class<?>... arg2) {
        // TODO Auto-generated method stub
        return null;
    }

    @Override
    public <T> Set<ConstraintViolation<T>> validateValue(Class<T> arg0,  String arg1, Object arg2, Class<?>... arg3) {
        // TODO Auto-generated method stub
        return null;
    }
}

public class FormCreator {

    MessagesApi msgAPI;
    Formatters formatador;
    Validador validador;
    FormFactory factory;

    public FormCreator() {
        msgAPI = new MessagesApi(null);
        formatador = new Formatters(msgAPI);
        validador = new Validador();
        factory = new FormFactory(msgAPI, formatador, validador);
    }


    // getters e setters
    public MessagesApi getmsgAPI() {
        return msgAPI;
    }
    public void setmsgAPI(MessagesApi msgAPI) {
        this.msgAPI = msgAPI;
    }
    public Formatters getFormatador() {
        return formatador;
    }
    public void setFormatador(Formatters formatador) {
        this.formatador = formatador;
    }
    public Validador getValidador() {
        return validador;
    }
    public void setValidador(Validador validador) {
        this.validador = validador;
    }
    public FormFactory getFactory() {
        return factory;
    }
    public void setFactory(FormFactory factory) {
        this.factory = factory;
    }
}

在我的控制器中，我必须输入如下内容:

And in my controller I have to put something like this:

@Inject
FormCreator formCreator = new FormCreator();

虽然我花了几个小时来发现这一点，但这个问题已经解决了.

althrough that I spent some hours to discover this, this question was solved.

另一个是，无论我做什么，bindFromRequest() 方法总是返回 null，并且没有，因为 eclipse，以及其他任何事情，这是因为我从这个工厂创建的表单中调用它.

Another one is, whatever I do, the method bindFromRequest() always returns null, and is no because the eclipse, and anything else, it's because I call it from a form created by this factory.

示例:

// never works
formCreator.getFactory().form(Diretor.class).bindFromRequest();

// works fine, but is deprecated
Form.form(Diretor.class).bindFromRequest();

使用这种已弃用方法的最新方法是什么?

What is the newest method to use instead this deprecated method?

提前致谢.

推荐答案

Play 2.5.x 文档说明:

The Play 2.5.x documentation states it:

要包装一个类，您必须将 play.data.FormFactory 注入您的控制器，然后允许您创建表单:

To wrap a class you have to inject a play.data.FormFactory into your Controller which then allows you to create the form:

Form userForm = formFactory.form(User.class);

Form userForm = formFactory.form(User.class);

所以第一步是将 FormFactory 注入您的控制器.你这样做:

So the first step is to inject the FormFactory into your controller. You do it like this:

package controllers;

import play.*;
import play.mvc.*;

public class Application extends Controller {

    @Inject FormFactory formFactory;

    ...
}

然后在处理表单提交请求的操作中，您可以像这样使用 FormFactory:

Then in the action where you handle the form-submission request you can use the FormFactory like this:

public Result handleFormSubmission() {
    formFactory.form(Director.class).bindFromRequest();
}

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