RailPanel
=========

.. granite:servercomponent:: /libs/granite/ui/components/coral/foundation/panel/railpanel

   The panel of the rail.

   It implements :doc:`/jcr_root/libs/granite/ui/components/coral/foundation/clientlibs/foundation/vocabulary/toggleable` vocabulary.

   Since the panel is usually hidden by default,
   app developer is encouraged to leverage situation to fetch the content of the panel lazily,
   especially then the content itself is quite expensive to prepare.

   It has the following content structure:

   .. gnd:gnd::

      [granite:PanelRailPanel] > granite:commonAttrs, granite:renderCondition, granite:container

      /**
       * The URL to fetch the content of the panel.
       *
       * If this property is specified then the content of the panel is loaded lazily instead.
       * Otherwise the content is loaded normally as per container convention.
       */
      - src (StringEL)

      /**
       * ``true`` to activate the panel initially; ``false`` otherwise.
       */
      - active (Boolean)


   Example::

      + mypanel
        - sling:resourceType = "granite/ui/components/coral/foundation/panel"
        + header
          - sling:resourceType = "granite/ui/components/coral/foundation/container"
        + body
          - sling:resourceType = "granite/ui/components/coral/foundation/container"
        + rail
          - sling:resourceType = "granite/ui/components/coral/foundation/container"
          + parentConfig
            - active = true
          + items
            + panel1
              - sling:resourceType = "granite/ui/components/coral/foundation/panel/railpanel"
              - active = true
            + panel2
              - sling:resourceType = "granite/ui/components/coral/foundation/panel/railpanel"
        + footer
          - sling:resourceType = "granite/ui/components/coral/foundation/container"