在JSF 2.0中用于向导模式的范围是什么? [英] What scope to use in JSF 2.0 for Wizard pattern?

问题描述

我有一个多页表单，又称向导模式，其中第1页对应于向导表单的第1步，第2页对应于第2步，依此类推.除最后一页外，每个页面上都有一个Next按钮，将您带到表单的下一页.最后一页上有一个提交按钮，用于提交向导中所有页面的所有数据.

I have a multi-page form, aka a Wizard pattern, where Page 1 corresponds to Step 1 of the wizard form, Page 2 corresponds to Step 2, etc. Each page other than the last has a Next button on it that takes you to the next page in the form. The final page has a submit button that submits all the data for all pages in the wizard.

我应该使用什么范围来维护在每个表单上输入的数据的状态?例如我应该使用包含在所有页面上输入的所有数据的View Scoped bean吗?因为我将导航到不同的页面(我认为这被认为是不同的视图"；所以如果我认为这是不同的视图"，则我相信，当您导航到下一个页面时，视图范围"数据将丢失)向导)

What scope should I use to maintain the state of the data entered on each form? e.g. should I use a View Scoped bean that holds all the data entered on all pages? Will that work since I'll be navigating to different pages (Which I believe are considered to be different "views"; and if they're different views, I believe the View Scoped data will be lost when you navigate to the next page in the wizard)

推荐答案

我相信，当您导航到向导的下一页时，查看范围"数据将会丢失)

是正确的.只要您与同一个视图进行交互，该视图作用域就会存在，并在创建新视图时将其丢弃.您正在寻找对话范围".任何JSF托管Bean范围都无法使用此功能.但是CDI @ConversationScoped .因此，如果您的环境碰巧支持CDI，则可以使用它:

That's correct. The view scope lives as long as you're interacting with the same view and get trashed whenever a new view get created. You're looking for the "conversation scope". This isn't available by any of the JSF managed bean scopes. This is however available by CDI @ConversationScoped. So if your environment happen to support CDI, you could make use of it:

import javax.enterprise.context.Conversation;
import javax.enterprise.context.ConversationScoped;
import javax.inject.Inject;
import javax.inject.Named;

@Named
@ConversationScoped
public class Wizard implements Serializable {

    @Inject
    private Conversation conversation;

    @PostConstruct
    public void init() {
        conversation.begin();
    }

    public void submitFirstStep() {
        // ...
    }

    // ...

    public String submitLastStep() {
        // ...

        conversation.end();
        return "someOtherPage?faces-redirect=true";
    }

    // ...
}

通过自动插入的cid请求参数来管理会话.

The conversation is managed by the automatically inserted cid request parameter.

如果您希望坚持使用JSF视图范围，那么最好的选择是创建一个页面，在其中您可以有条件地呈现多个步骤:

If you'd like to stick to the JSF view scope, then your best bet is to create a single page wherein you render the multiple steps conditionally:

<h:panelGroup rendered="#{wizard.step == 1}">
   <ui:include src="/WEB-INF/wizard/step1.xhtml" />
</h:panelGroup>
<h:panelGroup rendered="#{wizard.step == 2}">
   <ui:include src="/WEB-INF/wizard/step2.xhtml" />
</h:panelGroup>
<h:panelGroup rendered="#{wizard.step == 3}">
   <ui:include src="/WEB-INF/wizard/step3.xhtml" />
</h:panelGroup>

或者，您可以使用第三方组件库，例如 PrimeFaces ，该库具有

Or, you could use a 3rd party component library like PrimeFaces which has a <p:wizard> component for exactly this purpose.

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