Defining Mapping 

To enable the exchange of data, you can bind nodes of a context to nodes from the context of a different controller. This process is called defining mapping. You define mapping for a node of the context that you are currently editing. The contexts of all cross-view controllers of the current component are always available as the target objects of mapping. The contexts of the interface controller of used components can also be used for mapping.

To define mapping, the following points must be observed:

 Regardless of whether you want to use a controller of the current or a used component, a usage declaration of the controller intended for mapping must be entered on the Properties tab page of the current controller.

 

You also have the option of creating the required controller usage directly on the Context tab page by clicking on Used Controller above the left context display. All available controllers are then displayed in a new window, that is, that all the controllers of your current component that can be used and the interface controllers of all components for which a component usage was declared.

 Just like mapping to the context of a view, it is not possible to map between two nodes of the same context.

Mapping that would lead to a recursive mapping relationship is not possible and is therefore not permitted by the Workbench.

 

It is not possible to define mapping for the root node CONTEXT. To create a mapping, it is therefore a prerequisite that a node is created below the root node first of all. However, for this sub-node of a root node, you can define mapping to the root nodes of a different context.

If the structure of the node to which mapping was defined is not yet available in the node of the context that is currently being edited, then it is created there as part of the mapping definition process.

 

Creating a Mapping Using Drag and Drop

The simplest way to create a mapping is to select the relevant context node of the used controller and then drag it to the desired node of the controller context being edited. After confirming the dialog box that follows, the context node of the foreign controller context has been copied to that of the currently edited context; at the same time, the desired mapping of this copy to the node in the original context was defined.

Updating Mapping

If changes were made within the node to which mapping was defined (in the graphic above, this is the context of the component controller), this leads to an inconsistent mapping status. If you check or activate the context that contains the note for which the mapping was defined (VIEW 1 in the above example), an error message is displayed. To overcome this inconsistency, in the context menu of the relevant node (in the example above, this is Node 1), choose Update Mapping. This has the result that the elements of the node of the current context are compared with the elements of the node on which the mapping was defined.

 When a view context node is updated, this can again result in an inconsistency of the existing data binding definitions with UI elements. You should therefore check whether, after updating the mapping, the data bindings of the UI elements to the elements of the context nodes are still correct.

Deleting Mapping

You can delete mapping between two context nodes by choosing the Delete Mapping context menu option.