Compose Mapping Expression editor

The Compose Mapping Expression editor is used to qualify the field-to-field mappings already defined in the Mapping view. The editor allows you to define more specifically how the values should be assigned and manipulated, and if necessary define when they should, or should not, happen. You can also add other fields and apply different built-in and user-defined functions where required.

The editor is available in the Broker Application Development perspective; it is launched when you double-click on a Target value field in the Overview view.

Compose Mapping Expression editor views

General Layout

Beneath the Mapping Details section at the top of the window there is a field called Mapping that shows the mapping information currently being edited. Directly under that is another field called Value of target field showing the current target. Target message fields are prefixed with t_ and source message fields are prefixed with s_.

Input areas

The top white window contains the target value, or values, and can be manipulated using the editor tools described below. The lower white box can contain conditional information. That is, if the Apply Condition box is checked, conditional information can be entered defining the conditions that determine if and how the mapping should take place in the panel below.

Operator buttons

The buttons on the right-hand side of the screen represent all the operators that can be inserted into the input areas described above. Position the cursor where you want the operator inserted and click on the appropriate button. The chosen operator is placed at the cursor position.

Fields drop-down list

There are two drop-down lists available towards the bottom of the panel. The drop-down on the left by default shows Source fields. By clicking on the drop-down arrow, Target fields can also be selected. When the button immediately to the right of the drop-down button is clicked, a list of Source or Target fields is displayed. These can be selected and then dragged to their required position in one of the two input boxes above.

Functions drop-down list

The right-hand drop-down list by default shows String Functions. By clicking on the drop-down arrow, other function types can also be selected. Clicking on the arrow to the right shows all the functions available for the function type selected. To use one of these functions you can first highlight the field or fields you want to apply the function to, select the function you want to use, and then drag and drop it onto the highlighted fields. Alternatively you can simply drag and drop the function where you want it and complete the necessary fields later. Typing the function name manually without using drag and drop will not work.

Compose Mapping Expression editor toolbar

The Compose Mapping Expression editor does not provide any additional icons and actions on the toolbar.

Related concepts
Mappings
Mapping types
Message mapping

Related tasks
Developing mappings

Related reference
Broker Application Development perspective