Best Practices for <apex:panelbar>

Adding a Collection of Child <apex:panelBarItem> Components to an <apex:panelBar> Component
An <apex:panelBar> component can only have <apex:panelBarItem> child components. Sometimes, though, you want to add a collection of child components. For example, you may want to add an item for each contact associated with an account. You can do this by wrapping <apex:panelBarItem> in an <apex:repeat> component, as follows:
Note

Note

For this page to display account data, the ID of a valid account record must be specified as a query parameter in the URL for the page. For example: https://Salesforce_instance/apex/myPage?id=001D000000IRosz

<apex:page standardController="account">
  <apex:panelBar >
    <apex:repeat value="{!account.contacts}" var="c">
      <apex:panelBarItem label="{!c.firstname}">one</apex:panelBarItem>
    </apex:repeat>
  </apex:panelBar>
</apex:page>