Creating Message Mapping Objects

The source or target structure is shown as a tree. The icons indicate which fields are obligatory fields. The structure also shows the cardinality. The cardinality defines how often an element or node is permitted to occur.

The figure shows the most important icons of the mapping editor and what they mean. Beneath the source and target structures, there is a window containing the expression editor. In the expression editor, you can display and edit the target field mapping for any target field.

If the elements of a particular node in the source structure have the same name as elements in the target structure, you can use the mass assignment option. To do so, drag the source node with the right mouse button and drop it to the target source node. Select Execute Default Matcher from the context menu. All lower-level fields with the same name are then assigned to each other.

In the Message Mapping Definition screen select Definition tab to see the field assignments (structure mapping) using connection lines, which are displayed between the source and target elements.

Alternatively you can display the mapping rules as text. To do so, do the following steps:

1. Close your Message Mapping screen.

2. In the menu select: Window → Preferences → Web Services → Enterprise Service Browser.

3. Set flag Use Expression Editor for Mapping.

4. Choose Apply.

5. Choose OK.

6. Open your Message Mapping.

   Now you can open the text based expression editor either by clicking on a target element or by clicking on the mapping function.

The figure shows the place, at which the flag Use Expression Editor for Mapping can be set.

To test your Message Mapping you need to create first an XML file with test data in the Enterprise Service Repository perspective.

The figure illustrates the steps described below.

To do so:

1. Open the context menu of your message mapping (click right mouse button).

2. Select Generate → XML File from the Context menu.

3. Maintain the required fields in the XML Generation Wizard.

4. Choose Finish.
5. Maintain the Data in the XML and save your settings.

Once you have created the XML File with your test data, you have to create a test case.

The figure illustrates the steps to create a test case for message mapping.

To create a test case, do the following:

1. Open again the context menu of your message mapping.

2. Select Run As → Run Configurations...-.

3. In the Run Configurations Wizard double click ESR Message Mapping.

4. Maintain the required fields and select the Message Mapping you want to test in Object Details area.

5. Specify the Test Data Details.

6. Apply and Run your Test.

Perform the following steps to use the concat function:

1. Select the target field in the target structure in which the result is to be entered.
2. To display the field in the expression editor, double click it.
3. Select the two fields in the source structure that are to be joined to form the target field.
4. To display the fields in the expression editor, use drag and drop.
5. Select the function type Text and choose concat.
6. To join the objects, choose the blue bubble in one of the source fields, keep the mouse button pressed, and drag the arrow across to the standard function.
7. Repeat the procedure with the remaining objects.

When you need to map data fields, use the function DateTrans to define transformations that transform one date format to another.

Perform the following steps to use the DateTrans function:

1. Choose the function type Date.
2. In the functions tree, choose TransformDate().
3. Join the objects.
4. Double-click the function to maintain the properties.
5. Specify the required date format.

On a technical level, a mapping tool must provide a solution for the following challenges:

• A unique result needs to be determined for each target field that is to be completed. In a message mapping, this is achieved by defining target field mappings.
• Optional nodes are only created if a rule is defined that specifies when an instance of the target structure is to be created. This creation can be achieved by assigning it to a source field or a source node. In the case of cardinalities > 1, you need to create rules to define how many instances of the target structure need to be created. If the source fields belong to a node with multiple instances, you need to define which instance of the source structure the field values are to be copied from, and to which instance of the target structure they are to be copied.

In a target field mapping, you create rules for each target field. These rules define the source fields used to determine the result value. The rules are not attached to the source field, but to the target field. Each source field can be reused in any number of target field mappings. However, there is only one target field mapping for each target field.

Functions of various types can be used within message mapping.

The mapping in the figure, Mapping with the If Function, shows whether the MaterialGroup tag is available in the source structure. If it is, the value is transferred to the target field; if not, a constant with the value Missing is entered.

If a structure is used more than once (multiple nodes) in a mapping, the structure is also relevant for the structure fields. To ensure that the source document is processed efficiently, the source document is placed in queues at runtime of message mapping. For every source field (and every source structure), a queue is created. This queue contains all values that appear. These queues are the basis for the mapping and are also created and used for all intermediate steps, such as standard functions. The queues also contain context information, for example, on which node the information about a value is contained.

Additional node functions are available for more complex mapping tasks; these node functions enable you to control the structure of the queue. You can display the queues for the current test instance in the data-flow editor.