对于OmniFaces,我也曾经通过在方法中创建
<o:include>as
UIComponent而不是a
TagHandler进行过尝试。这样,在恢复视图阶段就可以记住正确的包含面,而包含组件树仅在渲染响应阶段发生变化,这正是我们想要实现的构造。
FaceletContext#includeFacelet()
enpreChildren()
这是一个基本的启动示例:
@FacesComponent("com.example.Include")public class Include extends UIComponentbase { @Override public String getFamily() { return "com.example.Include"; } @Override public boolean getRendersChildren() { return true; } @Override public void enpreChildren(FacesContext context) throws IOException { getChildren().clear(); ((FaceletContext) context.getAttributes().get(FaceletContext.FACELET_CONTEXT_KEY)).includeFacelet(this, getSrc()); super.enpreChildren(context); } public String getSrc() { return (String) getStateHelper().eval("src"); } public void setSrc(String src) { getStateHelper().put("src", src); }}注册
.taglib.xml如下:
<tag> <tag-name>include</tag-name> <component> <component-type>com.example.Include</component-type> </component> <attribute> <name>src</name> <required>true</required> <type>java.lang.String</type> </attribute></tag>
在以下视图中可以正常工作:
<h:outputscript name="fixViewState.js" /><h:form> <ui:repeat value="#{includeBean.includes}" var="include"> <h:commandButton value="Include #{include}" action="#{includeBean.setInclude(include)}"> <f:ajax render=":include" /> </h:commandButton> </ui:repeat></h:form><h:panelGroup id="include"> <my:include src="#{includeBean.include}.xhtml" /></h:panelGroup>以及以下辅助bean:
@ManagedBean@ViewScopedpublic class IncludeBean implements Serializable { private List<String> includes = Arrays.asList("include1", "include2", "include3"); private String include = includes.get(0); private List<String> getIncludes() { return includes; } public void setInclude(String include) { return this.include = include; } public String getInclude() { return include; }}(此示例期望include
filesinclude1.xhtml
,include2.xhtml
并且include3.xhtml
与主文件位于同一基本文件夹中)
本
fixViewState.js可以在这个回答中找到:H:的commandButton /
H:commandlink不首先点击工作,只能在第二次点击。为了修复JSF问题790,此脚本是必需的,从而在存在多个更新彼此父级的ajax表单时,视图状态会丢失。
还要注意,这种方式每个包含文件
<h:form>在必要时都可以拥有自己的文件,因此您不必将其放在包含文件周围。
这种方法即使在Mojarra中也可以正常工作,即使回发请求来自include内的表单,但是在MyFaces中也很难失败,但在初始请求期间已经存在以下异常:
java.lang.NullPointerException at org.apache.myfaces.view.facelets.impl.FaceletCompositionContextImpl.generateUniqueId(FaceletCompositionContextImpl.java:910) at org.apache.myfaces.view.facelets.impl.DefaultFaceletContext.generateUniqueId(DefaultFaceletContext.java:321) at org.apache.myfaces.view.facelets.compiler.UIInstructionHandler.apply(UIInstructionHandler.java:87) at javax.faces.view.facelets.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:49) at org.apache.myfaces.view.facelets.tag.ui.CompositionHandler.apply(CompositionHandler.java:158) at org.apache.myfaces.view.facelets.compiler.NamespaceHandler.apply(NamespaceHandler.java:57) at org.apache.myfaces.view.facelets.compiler.EncodingHandler.apply(EncodingHandler.java:48) at org.apache.myfaces.view.facelets.impl.DefaultFacelet.include(DefaultFacelet.java:394) at org.apache.myfaces.view.facelets.impl.DefaultFacelet.include(DefaultFacelet.java:448) at org.apache.myfaces.view.facelets.impl.DefaultFacelet.include(DefaultFacelet.java:426) at org.apache.myfaces.view.facelets.impl.DefaultFaceletContext.includeFacelet(DefaultFaceletContext.java:244) at com.example.Include.enpreChildren(Include.java:54)
MyFaces基本上在视图构建时结束时释放Facelet上下文,使其在视图渲染时不可用,从而导致NPE,因为内部状态具有多个无效属性。但是,可以在渲染期间添加单个组件而不是Facelet文件。我真的没有时间调查这是我的错还是MyFaces的错。这就是为什么它还没有出现在OmniFaces中的原因。
如果您仍在使用Mojarra,请随时使用。但是,我强烈建议在同一页面上使用所有可能的用例对它进行彻底的测试。Mojarra具有一些与状态保存有关的怪癖,这些怪癖在使用此构造时
可能会 失败。



