在 JSF 2 中，绑定过程发生在执行操作之前

发布于 2024-12-22 13:37:41 字数 1504 浏览 0 评论 0原文

我将 PrimeFaces 与 JSF 2.0 一起使用，我有这样的布局：

<h:panelGroup layout="block" id="panelGroup" binding="#{bean.boundPg}" />
<p:commandButton value="Update" action="#{bean.updateMe}" update="panelGroup" />

其中，bean 是 SessionBean。通过使用 log4j 进行调试，我发现绑定过程在执行 updateMe 操作之前调用了 getBoundPg。所以视图总是过时的。

你知道为什么以及如何颠倒这个顺序吗？谢谢！

------------- 编辑 ---------------

我正在为问答游戏制作一个网络应用程序。

<h:panelGroup layout="block" id="pgContents" binding="#{bean.boundContents}" />
<p:commandButton value="Prev page" action="#{bean.prevPage}" update="pgContents" /> 
<p:commandButton value="Next page" action="#{bean.nextPage}" update="pgContents" />

pgContents 包含许多 h:pannelGroup，每个子组包含一个显示测验内容的标签，一个用于播放器的 h:inputText给出他们的答案。由于某些原因，我必须以编程方式生成 pgContents 的子级。

上一页和下一页按钮将检索上一组/下一组测验

下面是bean（跳过getters和setters）

@ManagedBean(name = "bean")
@SessionScoped
public class LessonHelper {

    private int currentPage;
    private HtmlPanelGroup boundContents;

    public void prevPage() {
        // decrease currentPage
        // fetch contents
        // add children for boundContents (label, inputText)
    }

    // nextPage() is similar
}

我的问题是，当我单击Prev/Next 按钮，绑定过程中先调用 getter getBoundContents，后调用 prevPage()/nextPage()，导致内容始终显示已经过时了。

原文

I'm using PrimeFaces with JSF 2.0, I have this layout:

<h:panelGroup layout="block" id="panelGroup" binding="#{bean.boundPg}" />
<p:commandButton value="Update" action="#{bean.updateMe}" update="panelGroup" />

in which, the bean is SessionBean. By using log4j to debug I found out that the binding process called getBoundPg before executing the action updateMe. So the view is always out-of-date.

Do you know why and how to reverse that order? Thanks!

------------- Edit ---------------

I'm making a web app for a quiz game.

<h:panelGroup layout="block" id="pgContents" binding="#{bean.boundContents}" />
<p:commandButton value="Prev page" action="#{bean.prevPage}" update="pgContents" /> 
<p:commandButton value="Next page" action="#{bean.nextPage}" update="pgContents" />

pgContents contains many h:pannelGroups, each sub-group contains a label showing the content of a quiz, a h:inputText for the player to give their answer. Because of some reasons, I had to generate the children of pgContents programmatically.

The Prev page and Next page buttons will retrieve the prev/next group of quiz

Below is the bean (getters & setters are skipped)

@ManagedBean(name = "bean")
@SessionScoped
public class LessonHelper {

    private int currentPage;
    private HtmlPanelGroup boundContents;

    public void prevPage() {
        // decrease currentPage
        // fetch contents
        // add children for boundContents (label, inputText)
    }

    // nextPage() is similar
}

My problem is that, when I click the Prev/Next button, the getter getBoundContents is called first in binding process, and the prevPage()/nextPage() is called later, which cause the content always out-of-date.

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