使用Richfaces和Omnifaces CombinedResourceHandler的结果是h:dataTable值方法被调用，尽管rendered="false“

Question

我正在运行Tomcat 7、JSF2.2、OpenWebBeans 1.6、OmniFaces1.8和Richfaces 3。我最近添加了Omnifaces CombinedResourceHandler，并注意到当页面上的表单提交时，它会导致调用datatable的值方法，尽管该方法位于未呈现的块中。

示例：

<h:body styleClass="bdyPage">
    <h:form id="form">
        <h:commandButton value="test button" />
        <h:panelGroup rendered="false">
            <h:outputText value="#{testBean.getTestString()}" />
            <h:dataTable id="testtable22" value="#{testBean.strings}" var="str"
                rowClasses="odd, even">
                <h:column>
                    <f:facet name="header">
                        test
                    </f:facet>
                    <h:outputText value="str" />
                </h:column>
            </h:dataTable>
        </h:panelGroup>
    </h:form>
</h:body>

我有一个简单的测试bean：

@Named("testBean")
@RequestScoped
public class TestBean1 implements Serializable {

  private static final long serialVersionUID = 1L;

    public String getTestString() {
        System.out.println("Test string");
        return "test string";
    }

    public List<String> getStrings() {
        List<String> strings = new ArrayList<String>();
        strings.add("hej");
        strings.add("hejsan");
        strings.add("hej hej!");
        System.out.println("getting strings");
        return strings;
    }

}

通常，getStrings()不会被调用，因为panelGroup被设置为不呈现。但是，当我运行时-- Omnifaces CombinedResourceHandler和Richfaces --当提交按钮不止一次按下时，getStrings()就会被调用。这似乎只影响h:dataTable组件的value属性。其他el表达式不会被调用。

我使用以下maven依赖项设置了一个小示例项目：

    <dependencies>
    <dependency>
        <groupId>org.richfaces.ui</groupId>
        <artifactId>richfaces-components-ui</artifactId>
        <version>4.3.7.Final</version>
    </dependency>
    <dependency>
        <groupId>org.richfaces.core</groupId>
        <artifactId>richfaces-core-impl</artifactId>
        <version>4.3.7.Final</version>
    </dependency> 
<!--    <dependency>  
    <groupId>org.richfaces</groupId>  
    <artifactId>richfaces</artifactId>  
  <version>5.0.0.Alpha3</version>  
</dependency>  
     -->
    <dependency>
        <groupId>javax.validation</groupId>
        <artifactId>validation-api</artifactId>
        <version>1.0.0.GA</version>
        <type>jar</type>
        <classifier>sources</classifier>
    </dependency>
    <dependency>
        <groupId>javax.validation</groupId>
        <artifactId>validation-api</artifactId>
        <version>1.0.0.GA</version>
        <type>jar</type>
    </dependency>
    <dependency>
        <groupId>org.omnifaces</groupId>
        <artifactId>omnifaces</artifactId>
        <version>1.8</version>
    </dependency>
    <dependency>
        <groupId>javax.enterprise</groupId>
        <artifactId>cdi-api</artifactId>
        <version>1.2</version>
    </dependency>
    <dependency>
        <groupId>org.apache.openwebbeans</groupId>
        <artifactId>openwebbeans-impl</artifactId>
        <version>1.6.2</version>
    </dependency>
    <dependency>
        <groupId>org.apache.openwebbeans</groupId>
        <artifactId>openwebbeans-jsf</artifactId>
        <version>1.6.2</version>
    </dependency>
    <dependency>
        <groupId>org.apache.openwebbeans</groupId>
        <artifactId>openwebbeans-el22</artifactId>
        <version>1.6.2</version>
    </dependency>
    <dependency>
        <groupId>org.apache.openwebbeans</groupId>
        <artifactId>openwebbeans-web</artifactId>
        <version>1.6.2</version>
    </dependency>
    <dependency>
        <groupId>org.glassfish</groupId>
        <artifactId>javax.faces</artifactId>
        <version>2.2.6</version>
    </dependency>
</dependencies>

我不会在项目或测试页面中使用任何richfaces组件。我只是把Richfaces作为一种依赖关系。我没有任何被合并的javascripts。如果我禁用Omnifaces或从pom文件中删除Richfaces，它将按预期工作。

我试过使用Richfaces 5，但我在那里也有类似的行为(尽管getter被称为getter的次数较少)。我没有尝试过最新的Omnifaces版本，因为它与OWB 1.6不兼容。

最有趣的一点可能是，如果我用一个JSTL <c:if>包围datatable，它就能工作。但我不想这么做，很明显.

我在这里做错什么了吗？这些版本的Omnifaces和Richfaces是否存在兼容性问题？

编辑:从datatable的getter调用堆栈

TestBean1.getStrings() line: 33 
TestBean1$$OwbNormalScopeProxy0.getStrings() line: not available    
NativeMethodAccessorImpl.invoke0(Method, Object, Object[]) line: not available [native method]  
NativeMethodAccessorImpl.invoke(Object, Object[]) line: not available   
DelegatingMethodAccessorImpl.invoke(Object, Object[]) line: not available   
Method.invoke(Object, Object...) line: not available    
BeanELResolver.getValue(ELContext, Object, Object) line: 87 
DemuxCompositeELResolver._getValue(int, ELResolver[], ELContext, Object, Object) line: 176  
DemuxCompositeELResolver.getValue(ELContext, Object, Object) line: 203  
AstValue.getValue(EvaluationContext) line: 183  
ValueExpressionImpl.getValue(ELContext) line: 185   
WrappedValueExpression.getValue(ELContext) line: 70 
TagValueExpression.getValue(ELContext) line: 109    
ComponentStateHelper.eval(Serializable, Object) line: 194   
ComponentStateHelper.eval(Serializable) line: 182   
HtmlDataTable(UIData).getValue() line: 732  
HtmlDataTable(UIData).getDataModel() line: 1822 
HtmlDataTable(UIData).setRowIndexWithoutRowStatePreserved(int) line: 484    
HtmlDataTable(UIData).setRowIndex(int) line: 473    
HtmlDataTable(UIData).visitColumnsAndColumnFacets(VisitContext, VisitCallback, boolean) line: 2104  
HtmlDataTable(UIData).visitTree(VisitContext, VisitCallback) line: 1446 
HtmlPanelGroup(UIComponent).visitTree(VisitContext, VisitCallback) line: 1701   
HtmlForm(UIComponent).visitTree(VisitContext, VisitCallback) line: 1701 
HtmlForm(UIForm).visitTree(VisitContext, VisitCallback) line: 371   
HtmlBody(UIComponent).visitTree(VisitContext, VisitCallback) line: 1701 
UIViewRoot(UIComponent).visitTree(VisitContext, VisitCallback) line: 1701   
FaceletViewHandlingStrategy.locateComponentByClientId(FacesContext, String) line: 2082  
FaceletViewHandlingStrategy.reapplyDynamicRemove(FacesContext, ComponentStruct) line: 2174  
FaceletViewHandlingStrategy.reapplyDynamicActions(FacesContext) line: 2116  
FaceletViewHandlingStrategy.buildView(FacesContext, UIViewRoot) line: 966   
RenderResponsePhase.execute(FacesContext) line: 99  
RenderResponsePhase(Phase).doPhase(FacesContext, Lifecycle, ListIterator<PhaseListener>) line: 101  
LifecycleImpl.render(FacesContext) line: 219    
FacesServlet.service(ServletRequest, ServletResponse) line: 647 
ApplicationFilterChain.internalDoFilter(ServletRequest, ServletResponse) line: 305  
ApplicationFilterChain.doFilter(ServletRequest, ServletResponse) line: 210  
StandardWrapperValve.invoke(Request, Response) line: 222    
StandardContextValve.invoke(Request, Response) line: 123    
NonLoginAuthenticator(AuthenticatorBase).invoke(Request, Response) line: 472    
StandardHostValve.invoke(Request, Response) line: 171   
ErrorReportValve.invoke(Request, Response) line: 99 
AccessLogValve.invoke(Request, Response) line: 936  
StandardEngineValve.invoke(Request, Response) line: 118 
CoyoteAdapter.service(Request, Response) line: 407  
Http11Processor(AbstractHttp11Processor).process(SocketWrapper<S>) line: 1004   
Http11Protocol$Http11ConnectionHandler(AbstractProtocol$AbstractConnectionHandler).process(SocketWrapper<S>, SocketStatus) line: 589    
JIoEndpoint$SocketProcessor.run() line: 312 
ThreadPoolExecutor(ThreadPoolExecutor).runWorker(ThreadPoolExecutor$Worker) line: not available 
ThreadPoolExecutor$Worker.run() line: not available 
TaskThread(Thread).run() line: not available [local variables unavailable]  

Answer 1

首先，getter方法不应该执行业务逻辑：如何以及何时为h:dataTable从数据库加载模型。一旦您将getter方法修复为只返回属性，那么多次调用它的关注点就完全没有必要了。

回到观察到的行为，未呈现的<h:dataTable>的getter方法可能会在“意外”时被调用，此时代码执行不带VisitHint#SKIP_UNRENDERED和/或VisitHint#SKIP_ITERATION的UIComponent#visitTree()。CombinedResourceHandler本身并没有这么做。至少不是直接的。它只操作组件树中的组件资源。但是，它有一个特定于RichFaces的黑客攻击，以提取其本地资源库方法。尽管如此，它的源代码似乎不会在任何地方触发visitTree()。要确定真正的原因，只需在getter方法上放置一个调试断点，并探索负责调用的调用堆栈。

至于明显的JSTL <c:if>厌恶(这里的“显然”这个词有点太强烈了)，这是阅读的食物：JSF2中的JSTL .合乎道理?

也就是说，最新的OmniFaces 1.x版本是1.8.3，而不是1.8。还请参阅下载部分。这也是值得的努力，以升级Mojarra的最新，即现在是2.2.12。