Compose Mapping Expression editor

The Compose Mapping Expression editor is used to qualify the field-to-field mappings that are already defined in the Mapping view. Use the editor to define more specifically how the values should be assigned and manipulated, and if necessary, 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 a Target value field in the Overview pane.

Compose Mapping Expression editor views

General Layout

The Mapping field shows the mapping information that is currently being edited. The Value of target field field shows 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 check box is selected, you can enter conditional information that defines the conditions that determine if and how the mapping should take place.

Operator buttons

The buttons on the right 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 to be inserted and click the appropriate button. The chosen operator is inserted at the cursor position.

Fields drop-down list

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

Functions drop-down list

The right-hand drop-down list shows String Functions by default. By clicking on the drop-down arrow, you can also select other function types. Clicking on the arrow to the right shows all the functions that are available for the selected function type. To use one of these functions, highlight the field or fields to which you want to apply the function, select the function that you want to use, and drag it onto the highlighted fields. (Alternatively, 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
Related tasks
Developing mappings