Creating Titled Sections and Subsections
You may want to divide a page into sections and subsections, starting each section or subsection with a header. The af:panelHeader component enables you create sections and subsections with a label and an icon at the top of each section or subsection header, as shown in the first example in the slide.
To enable users to toggle the display of contents under each section or subsection header, use the af:showDetailHeader component instead. This is similar to the af:panelHeader component, except that it renders a toggle icon that enables users to hide or display the section or subsection contents. The second example in the slide shows a top section with its contents displayed, and a subsection with its contents hidden. Partial Page Rendering (PPR), which you learn about later in this lesson, is automatically used to refresh a section of the page when the user selects to hide or show contents under the header.
The disclosed attribute on af:showDetailHeader specifies whether to show or hide the contents under its header. The default is false, meaning the contents are hidden.