JSF f:event preRenderView 是由 f:ajax 调用和部分渲染触发的，还有别的吗? [英] JSF f:event preRenderView is triggered by f:ajax calls and partial renders, something else?

问题描述

所以我们有一个 f:event:

So we have an f:event:

   <f:metadata>
    <f:event type="preRenderView" listener="#{dashboardBacking.loadProjectListFromDB}"/>
   </f:metadata>

在初始页面加载(渲染)时根据需要触发.

Which is triggered as desired on initial page load (render).

然而，这个 preRenderView 事件也是由 ajax 部分页面渲染触发的，它重新渲染一个带有 id projectListing 的 h:panelgroup，如下所示.

However this preRenderView event is also triggered by an ajax partial page render, which re-renders an h:panelgroup with the id projectListing, as below.

<h:commandButton action="#{mrBean.addProject}" value="Create Project"
                                     title="Start a new project">
   <f:ajax render="projectListing" />
</h:commandButton>

我只希望在初始页面呈现时调用dashboardBacking.loadProjectListFromDB，而不是在有ajax 部分呈现时调用.我可以使用更合适的事件或方法吗?

I only want the dashboardBacking.loadProjectListFromDB to be called for the initial page render, but not when there is an ajax partial render. Is there a more appropriate event or method I could be using?

推荐答案

另一种选择是将您的 preRenderView 功能放在 @PostConstruct 的 方法中ViewScoped 托管 bean.此逻辑将在 bean 初始化时执行，并且您为所有 ajax 请求维护相同的 bean 实例，直到您更改视图.

Another option would be to put your preRenderView functionality in a @PostConstruct method of a ViewScoped managed bean. This logic would be executed when the bean is initialized, and you you maintain the same instance of the bean for all your ajax requests until you change views.

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