Question

我在JavaScript中这样做：

function doClick() {
  var theValue = document.getElementById("theForm:theField").value;
  var theLength = theValue.length;

  if( theLength <= 3 )  --> Error
  {
    alert('Character length too small.');
  }
}

thefield是一个JSF组件：

<h:form id="theForm">
  <h:commandButton id="theField" action="#{theBean.doFunctionA}" onclick="doClick()"/>

当我在IE中呈现此内容时，它会显示此错误：

Caused by: javax.faces.view.facelets.FaceletException: Error Parsing /viewMetadata/pages/thePage.xhtml: Error Traced[line: 66] The content of elements must consist of well-formed character data or markup.
    at org.apache.myfaces.view.facelets.compiler.SAXCompiler.doCompileViewMetadata(SAXCompiler.java:716)
    at org.apache.myfaces.view.facelets.compiler.Compiler.compileViewMetadata(Compiler.java:126)
    at org.apache.myfaces.view.facelets.impl.DefaultFaceletFactory._createViewMetadataFacelet(DefaultFaceletFactory.java:311)
    at org.apache.myfaces.view.facelets.impl.DefaultFaceletFactory.getViewMetadataFacelet(DefaultFaceletFactory.java:394)
    at org.apache.myfaces.view.facelets.impl.DefaultFaceletFactory.getViewMetadataFacelet(DefaultFaceletFactory.java:376)
    at org.apache.myfaces.view.facelets.FaceletViewDeclarationLanguage._getViewMetadataFacelet(FaceletViewDeclarationLanguage.java:1940)
    at org.apache.myfaces.view.facelets.FaceletViewDeclarationLanguage.access$000(FaceletViewDeclarationLanguage.java:129)
    at org.apache.myfaces.view.facelets.FaceletViewDeclarationLanguage$FaceletViewMetadata.createMetadataView(FaceletViewDeclarationLanguage.java:2049)
    at org.apache.myfaces.lifecycle.RestoreViewExecutor.execute(RestoreViewExecutor.java:161)
    at org.apache.myfaces.lifecycle.LifecycleImpl.executePhase(LifecycleImpl.java:171)
    at org.apache.myfaces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118)
    at javax.faces.webapp.FacesServlet.service(FacesServlet.java:189)
    ... 52 more

如果我用这个替换错误行：

if( theLength == '3' || theLength == '2' || theLength == '1')

然后一切正常。我真的不明白究竟发生了什么？

Answer 1

给出错误消息：

Caused by: javax.faces.view.facelets.FaceletException: Error Parsing 
/viewMetadata/pages/thePage.xhtml: Error Traced[line: 66]
The content of elements must consist of well-formed character data or markup.

听起来它正试图将其解析为XML。您应该阅读JSF中通常需要的转义，但尝试的第一件事就是将其转换为XML：

if (theLength &lt;= 3)

在诊断错误时，重要的是要意识到这实际上并没有触及浏览器的Javascript引擎 - 问题在于生成页面。

JavaScript是否支持＆lt; =运算符？

1 个答案: