是否将 f:event 放在 f:metadata 中重要吗？
wrt 如何使用 f 对 GET 请求执行操作:viewParam?
<f:metadata>
<f:viewParam name="id" value="#{tInputBean.id}" />
<f:event type="preRenderView" listener="#{tInputBean.init}" />
</f:metadata>
我有兴趣知道如果将 preRenderView f:event 放置在f：是否有元数据。我检查了 Java EE6 教程、Java Server Faces 2.0 Complete Reference 和 Core JSF2，它们都没有 f:metadata 中的 f:event 示例，但我在网上看到了很多这样的示例。
JSF2 Compl.Ref 说第 540 页
f:metadata 标签封装了用于指定的元素集 Facelet 视图的元数据，因此必须是 f:view 标签可能不会出现在模板中。从 JSF2.0 开始，唯一 该标签的目的是封装f:viewParam标签。
将 f:event （通常用于支持 f:viewParam）放入 f:metadata 中是否具有特殊含义，或者只是为了在视觉/逻辑上将其与 f:viewParam 一起分组？
w.r.t. How to execute action on GET request with f:viewParam?
<f:metadata>
<f:viewParam name="id" value="#{tInputBean.id}" />
<f:event type="preRenderView" listener="#{tInputBean.init}" />
</f:metadata>
I'm interested to know whether it matters if a preRenderView f:event is placed inside the f:metadata or not. I've checked the Java EE6 tutorial, Java Server Faces 2.0 Complete Reference, and Core JSF2, and none of them have examples of f:event inside f:metadata, but I've seen lots of examples online like this.
JSF2 Compl.Ref says p.540
The f:metadata tag encapsulates the set of elements used to specify
the metadata for a Facelet view, and therefore must be a child of the
f:view tag and may not appear in a template. As of JSF2.0, the only
purpose of this tag is to encapsulate f:viewParam tags.
Does placing the f:event (often used to support an f:viewParam) inside the f:metadata have a special meaning, or is it just to help group it alongside the f:viewParam visually/logically ?
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不，
并不严格要求放置在请注意，在即将推出的 JSF 2.2 中，将引入新的
标记。 No, the
<f:event>is not strictly required to be placed inside<f:metadata>. It can be attached to any component. It's indeed for pure self-documentary purposes placed inside the<f:metadata>whenever you have a bunch of<f:viewParam>s and would like to hook a<f:event>to invoke an action after all those view parameters have been set. It can even be placed outside/before those<f:viewParam>s, but it makes the code not more self-documenting.Note that in the upcoming JSF 2.2, a new
<f:viewAction>tag will be introduced which in turn is supposed to replace the<f:event type="preRenderView">in the<f:metadata>.