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问题:

I have a static menu in the sidebar which I include in every JSF page. The menu looks like so:

  <li class="nav-header">Item 1</li>
  <li class="active"><a href="index.xhtml">Item 2</a></li>
  <li><a href="new_workload.xhtml">Item 3</a></li>
  <li><a href="import_workload.xhtml">Item 4</a></li>

Adding a class="active" to the <li> highlights the menu. How do I go about making sure selected item is highlighted dynamically in JSF2?

I know PrimeFaces and RichFaces have ready made components for this, but I want to try a pure JSF 2 solution first. A pure client side JavaScript solution is also acceptable.

回答1:

You can get the current view ID in EL as follows

#{view.viewId}

So, this should do

class="#{view.viewId eq '/index.xhtml' ? 'active' : ''}"

It'd be easier to hold all those links in some List<Page> so that you can just do something like

<li class="nav-header">#{menu.header}</li>
<ui:repeat value="#{menu.pages}" var="page">
    <li class="#{view.viewId eq page.viewId ? 'active' : ''}">
        <h:link value="#{page.title}" outcome="#{page.viewId}" />
    </li>
</ui:repeat>

instead of copypasting the same piece of code over and over.

回答2:

I've used @BalusC idea plus his other tip at 12473461 but with some modification:

<ul>
  <li class="#{view.viewId eq '/admin/index.xhtml' ? 'active' : ''}"><h:link value="Main" outcome="main"/></li>
  <li class="#{fn:startsWith(view.viewId, '/admin/sess1/') ? 'active' : ''}"><h:link value="Session 1" outcome="sess1"/></li>
  <li class="#{fn:startsWith(view.viewId, '/admin/sess2/') ? 'active' : ''}"><h:link value="Session 2" outcome="sess2"/></li>
  <li class="#{fn:startsWith(view.viewId, '/admin/sess3/') ? 'active' : ''}"><h:link value="Session 3" outcome="sess3"/></li>
</ul>

回答3:

My solution is based on custom component:

<?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:composite="http://java.sun.com/jsf/composite" xmlns:c="http://java.sun.com/jsp/jstl/core" >
<composite:interface>
    <composite:attribute name="outcome" />
    <composite:attribute name="label" />
</composite:interface>

<composite:implementation>
    <li class="menuItem #{view.viewId == cc.attrs.outcome ? 'active' : ''}">
        <h:outputText value="#{cc.attrs.label}" rendered="#{view.viewId eq cc.attrs.outcome}"/>
        <h:link outcome="#{cc.attrs.outcome}" value="#{cc.attrs.label}" rendered="#{view.viewId ne cc.attrs.outcome}" />
    </li>
</composite:implementation>
</html>

Used in code:

<html xmlns="http://www.w3.org/1999/xhtml" xmlns:h="http://java.sun.com/jsf/html" xmlns:ui="http://java.sun.com/jsf/facelets" xmlns:my="http://java.sun.com/jsf/composite/my">
...
<ul class="nav">
     <my:menuItem outcome="/home.xhtml" label="Home" />
</ul>