### Creating an Invoking External Service

The Invoke External Service is used to invoke external, WSDL-based business or proxy services. Configuring an Invoke Service can include the following tasks:

- Select an Operation
- Define Input and Output Variables
- Add General Information

Related Topics

- Configuring the Start Node
- About Scope
- Split-Join Properties View - Invoke External Service

#### Selecting an Operation

An operation must be selected upon which to base the Invoke External Service. You must select this operation before you can configure Input and Output variables. To select an operation:

1. Select the Invoke External Service for which you wish to select an operation and open the Properties view.
2. From the Operations tab in the Properties view, select Browse to launch the Service Browser.
3. In the Service Browser, drill down to the desired service and select a Binding and then an operation.
4. Click OK. The selected operation and its Service Location appear in the operation page.

Note: | Clicking a selected Service Location will open the file.

#### Defining Input and Output Variables

An Invoke External Service requires both an Input Variable and an Output Variable, unless it is a one-way invocation. The procedure to configure these variables is essentially the same. Either type of variable can be global (that is, available within the entire Split-Join) or local (that is, available within a particular context Scope.) To define either an Input or Output variable:

1. Define the Message Variable. This can be done in two ways:

1. Select a pre-existing variable from the Message Variable menu.
2. Create a new Message Variable (following steps).

Note: | If there are no available Message Variables associated with the previously chosen operation, you must create a new Message Variable.

To create a new Message Variable:

1. Select Create Message Variable from the Message Variable menu. The Create Message Variable Dialog appears.
2. Provide a name for the variable.
3. Make the variable either global or local. Global variables are accessible within the entire Split-Join, whereas local variables are restricted to the current Scope.
4. Click OK.

Note that Message Type Namespace and Message Type are displayed automatically on the properties page once a variable is defined.

#### Adding General Information

General information is useful for making a node more legible. It includes the ability to add a unique identifier, or Label, to the node and to supplement it with notes, or Documentation. General information is optional.

1. To add a Label to a node, open the Properties view and enter a unique, identifying string in the Label field. The Label that you enter appears underneath the node in the Canvas Area. Alternatively, you can simply double-click the string under the icon and edit.
2. To add Documentation to a node, open the Properties view and enter any notes that you think are important in the Documentation field.