<af:train>

Model

The train takes a model of type org.apache.myfaces.adf.model.MenuModel that in turn extends a TreeModel. The last node along the focus path and its siblings are rendered as train stops. The default MenuModel implementation knows how to go from the current viewId to the focusRowKey. Notice that the MenuModel has no special knowledge of page navigation and places no requirements on the nodes that go into the tree. The last node along with its sibling, in the tree are stamped out using the "nodeStamp" facet, which should contain a commandNavigationItem component. This allows the default actionListener mechanism to be used for page navigation.

Note: When using Facelets as the page declaration language (PDL), the 'nodestamp' facet, if explicitly specified, should contain only one commandNavigationItem. Multiple components are not supported by this facet.

Behavior

The train behavior (how the train takes the user through its steps in a multi-step process) is dictated by the model implementation. Product teams are encouraged to implement custom behavior to suit their needs. The following behaviors allow the user to walk through a series of steps in a sequential order, but they exhibit slightly different behaviors.

• "Plus One" - From the current stop the user can navigate to any previous visited stops and the next enabled stop (in unvisited state). The remaining stops appear disabled.
  So, if the user is on the 5th step of a process and goes back to step 2, then the user can only navigate to step 1 (which appears as a visited stop) and step 3 (appears as an unvisited stop). Steps 4 and 5 cannot be reached (and the corresponding stops appear disabled).
• "Max Visited" - From the current stop the user can navigate to any previous stops and the next enabled stop (or upto the max visited stop). If the current stop happens to be the max visited stop then the next stop is enabled (and in unvisited state). The remaining stops appear disabled.
  So, if the user is on the 5th step of a process and goes back to step 2, then the user can navigate from step 2 to steps 1, 2, 3, 4, and 5, as they all have been visited (except for the current stop they all appear in visited state). Now if the user in on step 5, step 6 will be enabled (and the stop appears in unvisited state).

The class org.apache.myfaces.adf.model.ProcessMenuModel and org.apache.myfaces.adf.model.ProcessUtils were created to support the "Plus One" and "Max Visited" scenarios. Please see the javadoc for these classes for more information.

Sub-Process

A multi-step process may be launched from within another multi-step process, or a multi-step process may be nested inside another process as one of its steps. When the user navigates to a step in a sub-process, the parent train is represented as an icon appended before and after the sub-train, to indicate that the sub-train is a sub-process.

Simplified Train Tag Usage

The tag usage for the train component has been simplified. This tag can be used in its simpler form as below:
<af:train value="#{my_bean.menuModel}"/>

• The benefits of using the simpler tag are:
  • Simpler and smaller jspx pages. There is no need to specify the nodestamp facet (that includes a commandNavigationItem) in every page that contains a train component.
  • This means that the commandNavigationItem component (that is used to stamp out the train stops) is now created implicitly. Also the EL expressions are bound to the relevant properties of the component automatically.
  • The properties of commandNavigationItem that are EL bound automatically are - action, disabled, immediate, messageType, shortDesc, showRequired, textAndAccessKey and visited.
  • The only requirement for using the simplified train tag is that customers need to ensure that the object that represents the model for a train stop, resemble (contain the same methods as) oracle.adf.view.rich.model.TrainStopModel . IOW, the object returned from the call to CollectionModel.getRowData(int) should be an object resembling TrainStopModel or be a subclass of TrainStopModel.
  • NOTE: Customers can still use the full-blown tag usage, depending on their specific use cases.

Geometry Management

• This component can be stretched by a parent layout component that stretches its children, e.g. panelStretchLayout, panelSplitter.
• This component uses overflow when there is not enough horizontal space to display all items.

Overflow

Train is an overflow component. It must be part of a supported layout in order to work properly on the page.

An overflow component requires that it is either:

• in a container that stretches its children, or
• in a container that has a set width.

Under these circumstances, when the overflow component is larger than the parent container, the overflow component will display an overflow button. Selecting the overflow button will show a popup containing the items that didn't fit on the page.

Setting up an overflow component with the following layouts is not supported. If you use one of these layouts, you may have unexpected and inconsistent results:

• in a container that does not stretch its children.
• in a container that displays multiple children horizontally without explicit sizes for each child. For example, a panelGroupLayout with layout='horizontal' would be invalid, but panelSplitter is OK because it has an explicitly set splitter position.
• setting the overflow component with a styleClass or inlineStyle that assigns a percentage width value. Note that this includes assigning styleClass='AFStretchWidth' on an overflow component.

Screen Shot(s)

Train component

Code Example(s)

<af:train var="node" value="#{menuModel}" id="t1">
  <f:facet name="nodeStamp">
    <af:commandNavigationItem text="#{node.label}"
                              action="#{node.getOutcome`}"
                              immediate="#{node.immediate}"
                              disabled="#{node.disabled}"
                              visited="#{node.visited}"
                              id="cn1"/>
  </f:facet>
</af:train>