ChildComponent.component

<apex:component controller="ChildComponentController">
  <apex:attribute name="componentValue" description="Attribute on the component."
                  type="String" required="required" assignTo="{!controllerValue}"/>
    <apex:pageBlock title="My Child Custom Component">
      <p>
        <code>componentValue</code> is "{!componentValue}"
        <br/>
        <code>controllerValue</code> is "{!controllerValue}"
      </p>
    </apex:pageBlock>
    <p>
    	Notice that the controllerValue has been lower cased using an Apex method.
    </p>
    <!--
        <p>
            Calling Parent Component: 
        </p>    
        <c:ParentComponent componentValue="Hi there, {!$User.FirstName}"/>
    -->
</apex:component>