也许有人可以启发我。
如果放置
<f:metadata>
<f:viewParam name="test" value="#{test.value}"/>
</f:metadata>
在模板内，setter
setValueis never called, i.e. the preRender method 'call()' is called without prior call to setter (see below in code example for reference).
If however, putting the metadata block inside the composition, it gets called as expected.
Is this normal behaviour or am I doing something wrong?
Thanks very much for any insights.
Hanspeter
For reference, here the complete code example of the non working version:
testtemplate.xhtml
<?xml version='1.0' encoding='UTF-8' ?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:h="http://java.sun.com/jsf/html"
xmlns:f="http://java.sun.com/jsf/core"
xmlns:ui="http://java.sun.com/jsf/facelets">
<f:metadata>
<f:viewParam name="test" value="#{test.value}"/>
</f:metadata>
<f:event type="preRenderView" listener="#{test.call}" />
<h:head>
<title>Test Template</title>
</h:head>
<h:body>
<ui:insert name="text" />
</h:body>
</html>
testcomposition.xhtml
<?xml version='1.0' encoding='UTF-8' ?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<ui:composition xmlns:ui="http://java.sun.com/jsf/facelets"
template="/templates/testtemplate.xhtml"
xmlns:f="http://java.sun.com/jsf/core"
xmlns:h="http://java.sun.com/jsf/html">
<ui:define name="text">
some text
</ui:define>
</ui:composition>
这里是工作版本的完整代码示例:
testtemplate.xhtml
<?xml version='1.0' encoding='UTF-8' ?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:h="http://java.sun.com/jsf/html"
xmlns:f="http://java.sun.com/jsf/core"
xmlns:ui="http://java.sun.com/jsf/facelets">
<f:event type="preRenderView" listener="#{test.call}" />
<h:head>
<title>Test Template</title>
</h:head>
<h:body>
<ui:insert name="text" />
</h:body>
</html>
testcomposition.xhtml
<?xml version='1.0' encoding='UTF-8' ?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<ui:composition xmlns:ui="http://java.sun.com/jsf/facelets"
template="/templates/testtemplate.xhtml"
xmlns:f="http://java.sun.com/jsf/core"
xmlns:h="http://java.sun.com/jsf/html">
<f:metadata>
<f:viewParam name="test" value="#{test.value}"/>
</f:metadata>
<ui:define name="text">
some text
</ui:define>
</ui:composition>
最佳答案
这是按规范规定的。 <f:metadata> tag documentation中提到了它:
Declare the metadata facet for this view. This must be a child of the
<f:view>. This tag must reside within the top level XHTML file for the given viewId, or in a template client, but not in a template. The implementation must insure that the direct child of the facet is a UIPanel, even if there is only one child of the facet. The implementation must set the id of the UIPanel to be the value of theUIViewRoot.METADATA_FACET_NAMEsymbolic constant.
原因很简单，因为元数据应该是特定于 View 的，而不是特定于模板的。无论如何，为了达到您的要求，您不能/不想放置 <f:metadata>里面 <ui:define>每个模板客户端，那么您最好的选择是使用一些带有 @ManagedProperty 的通用 bean .
另请参阅:
关于JSF f :viewParam not calling setter if located in template. xhtml，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/9553659/