Using Application Views in WebLogic Process Integrator

 

This section contains information on the following subjects:

• Before You Begin

• Introduction to Using Application Views in WebLogic Process Integrator

• Using Application Views in WebLogic Process Integrator

  • Scenario 1: Setting Up a Task Node to Call an Application View Service

  • Scenario 2: Setting Up an Event Node to Wait for a Response from an Asynchronous Application View Service

  • Scenario 3: Creating a Workflow that is Started by an Application View Event

  • Scenario 4: Setting Up an Event Node to Wait for an Application View Event

 

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Before You Begin

The following prerequisites must have been met before you can invoke an application view service or receive an application view event in WebLogic Process Integrator:

• You have created an application view and defined services and events for the application view.

• The application view and its adapter are deployed. If you plan on calling application view services and events from a running workflow, the application view must be deployed, as well.

• WebLogic Process Integrator is running.

• WebLogic Application Integration is running.

• The Application Integration Plug-in (AI Plug-in) has been loaded.

• You have received information about the required business logic for the workflows you are defining. This information usually comes from the business analyst or someone similar.

• A workflow template definition is open.

 

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Introduction to Using Application Views
in WebLogic Process Integrator

After you create all the required application view services and events for your enterprise, use the application views to execute your business processes. The simplest way to do this is by using WebLogic Process Integrator to design workflows that use the application view services and events.

WebLogic Process Integrator provides a GUI-based environment for designing business process workflows. These workflows can include application view services and events defined using Application Integration. For complete information on Process Integrator, see "BEA WebLogic Process Integrator."

 

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Using Application Views in WebLogic Process Integrator

There are four ways to use application view services and events in WebLogic Process Integrator:

• Scenario 1: Setting Up a Task Node to Call an Application View Service

• Scenario 2: Setting Up an Event Node to Wait for a Response from an Asynchronous Application View Service

• Scenario 3: Creating a Workflow that is Started by an Application View Event

• Scenario 4: Setting Up an Event Node to Wait for an Application View Event

Use these scenarios in combination with each other to create your own workflows. This document does not fully explain how to use WebLogic Process Integrator. For complete information on WebLogic Process Integrator, see the WebLogic Process Integrator User Guide or see http://www.oracle.com/technology/documentation/index.html.

Scenario 1: Setting Up a Task Node to Call
an Application View Service

In your organization, there may be situations in which you want to call an application view service from within a workflow. To do this, add a task node to the workflow, then add an appropriate Application View Service action to the task node. When the workflow is saved and activated, the application view service will be called whenever the task node executes.

Steps for Setting up a Task Node to Call
an Application View Service

Follow these steps to create a task node that calls an application view service:

1. Within WebLogic Process Integrator Studio, open a template definition. The Workflow Design window displays.
   
   
    

2. Create a task node if one does not already exist.

3. Double-click the task node that will call the application view service. The Task Properties dialog box displays.
   
   
    
    

4. In the Actions area, select the tab from which you want the service to be called. Your tab choice depends on your business processes.

5. Click Add. The Add Action dialog box displays.
   
   
    

6. From the Action category tree, select Workflow Actions, Set Workflow Variable, and click OK. The Set Workflow Variable dialog box displays.
   
   
    

7. In the Variable To Be Set list, select an XML variable to contain the input data for the application view service.

8. Click OK.

9. On the Task Properties dialog box, click Add. The Add Action dialog box displays.
   
   
    

10. From the action tree, select AI Actions, Call Application View Service and click OK. The Call Service dialog box displays.
    
    
     

11. In the application view tree, navigate to and select the service you want to call.

    The application view tree organizes application view services by folder (example: EastCoast.Sales) and application view (example: CustomerManagement). All application view services are at the lowest level of the hierarchy.

    Note: To check for newly saved application views and events at any time, click Refresh Tree.

12. In the Request Document Variable list, select an XML variable.

    Because this XML variable serves as the input document of the application view service, make sure the variable is properly set before the service is called.

    Note: If you need to examine the XML schema of the input document, click View Request Definition. The View Definition dialog box displays. Click Close when finished.
    
    

    
     

13. To call the application view synchronously, select Synchronous, or select Asynchronous to call the application view asynchronously.

    Note: A node that synchronously calls a service will wait for the service to return a response document before the workflow can continue. If the node asynchronously calls a service, the workflow will continue.

14. For synchronous services that require a response, select an already-defined XML variable in the Response Document Variable list. When WebLogic Process Integrator calls the application view service, a response is returned. When WebLogic Process Integrator receives the response from the application view service, the Response Document Variable stores the response. If you do not care about the response, skip this step.

    Note: If you need to examine the XML schema of the response document, click View Response Definition. The View Definition dialog box displays. Click Close when finished.
    
    

    
     

15. For asynchronous services that require a response, select an already-defined string variable in the Request ID Variable list.

    When the node calls the application view service, the node does not wait for a response and allows the workflow to continue processing. The workflow uses the Request ID Variable to allow asynchronous event nodes to receive the service response. If you do not care about the asynchronous service response, skip this step.

    Note: When you set up a task node to call an asynchronous application view service, the result will be returned to WebLogic Process Integrator. The workflow identifies this response using the Request ID Variable you selected. In a typical workflow, you will want to set up a corresponding event node that waits for this response. For more information on creating such an event node, see Scenario 2: Setting Up an Event Node to Wait for a Response from an Asynchronous Application View Service.

16. Click OK to save the action.

17. On the Task Properties dialog box, click OK to save the node.

Scenario 2: Setting Up an Event Node to Wait for
a Response from an Asynchronous
Application View Service

This section explains how to receive an asynchronous application view service response and handle any errors it may contain.

Receiving an Asynchronous Application View
Service Response

In a workflow, whenever an action calls an application view service asynchronously (see Scenario 1: Setting Up a Task Node to Call an Application View Service), the application view service will return a response. Normally, if you care about the response, you will want to set up a corresponding asynchronous event node to wait for the response. This section explains a highly simplified scenario in which an event node receives an application view service response without checking for errors.

Handling Errors in an Asynchronous Application View
Service Response

Although this scenario does not handle errors returned in the application view service response, you will normally want to handle errors in your own workflows. To handle asynchronous service response errors in your workflows, use the new features included in the AI Plug-in.

The AI Plug-in includes a new variable type, AsyncServiceResponse, and three new functions:

• AIHasError()

• AIGetErrorMsg()

• AIGetResponseDocument()

For complete documentation of these functions, see Explanation of Functions Provided by the AI Plug-in.

Steps for Setting Up an Event Node to Wait for a Response
from an Asynchronous Application View Service

To set up an asynchronous event node to wait for a response from an asynchronous application view service, create an event node, then set up the event node to wait for an event of type "AI AsyncResponse." When you set up an event node to wait for an asynchronous response from an application view service, the event node uses a designated Request ID Variable to receive the response. As long as the service-calling task node and the response-receiving event node use the same Request ID Variable, the asynchronous event node will correctly receive the service response.

Follow these steps to set up an event node to wait for a response from an asynchronous application view service:

1. Within WebLogic Process Integrator Studio, open a workflow template definition. The Workflow Design window displays.
   
   
    

2. Create an event node if one does not already exist. This event node will wait for an asynchronous response from a designated application view service.

3. Double-click the event node. The Event Properties dialog box displays.
   
   
    

4. In the Description field, enter a name (optional).

5. In the Type list, select AI Async Response.

6. In the Request ID Variable list, select an already-defined string variable. WebLogic Process Integrator will listen for an asynchronous response with an ID matching this variable.

   Note: The purpose of this event node is to wait for a response to a Call Application View Service action that was called asynchronously earlier in the workflow. The Call Application View Service action sets the Request ID Variable. To make the action and this event node work together, they must both use the same Request ID Variable. For more information on setting up the Call Application View Service action, see Scenario 1: Setting Up a Task Node to Call an Application View Service.

7. In the Asynchronous Service Response Variable list, select a variable to store the response data itself. It must be of type AsyncServiceResponse. If you do not care about the response data, skip this step.

8. Click OK to save the event node.

Explanation of Functions Provided by the AI Plug-in

When using the Application Integration Plug-in, use the new functions AIHasError(), AIGetErrorMsg(), and AIGetResponseDocument() to interrogate AI Asynch Response. If the Application Integration Plug-in is installed in WebLogic Process Integrator, then you have access to these new functions. Using these functions, you can set up decision nodes to handle success and failure conditions.

AIHasError()

Use AIHasError() to determine the status of an asynchronous service response.

Operands:

AsyncServiceResponse variable

Preconditions:

You have created a variable of type AsyncServiceResponse. You have called an asynchronous application view service. The application view service has returned a response, which is stored in your AsyncServiceResponse variable.

Returns:

Boolean

Output explanation:

False: The asynchronous application view service call was successful.
True: The asynchronous application view service call failed.

AIGetErrorMsg()

Use AIGetErrorMsg() to retrieve the error message string returned by an asynchronous application view service.

Operands:

AsyncServiceResponse variable

Preconditions:

You have created a variable of type AsyncServiceResponse. You have called an asynchronous application view service. The application view service has returned a response, which is stored by your AsyncServiceResponse variable.

Returns:

String

Output explanation:

Error string: Returns an error string explaining why the asynchronous application view response failed.

Empty string: There was no error.

AIGetResponseDocument()

Use AIGetResponseDocument() to retrieve the actual XML response document returned by an asynchronous application view service.

Operands:

AsyncServiceResponse variable

Preconditions:

You have created a variable of type AsyncServiceResponse. You have called an asynchronous application view service. The application view service has returned a response, which is stored by your AsyncServiceResponse variable.

Returns:

XML

Output explanation:

XML document: Returns an XML document representing the asynchronous service response.

Null: No response document was returned, because an error ocurred.

Scenario 3: Creating a Workflow that is Started
by an Application View Event

You may want to create a workflow that starts whenever a designated application view event occurs. To set up a workflow to be started by an application view event, edit the workflow's start node so it responds to an event of type AI Start, then select the appropriate application view event. If necessary, you can set up conditions on which to filter the event. After you save and activate the workflow, the start node will execute each time the application view event occurs.

Steps for Creating a Workflow that is Started
by an Application View Event

Follow these steps to set up a workflow with a start node that is triggered by an application view event.

1. Within WebLogic Process Integrator Studio, open a template definition. The Workflow Design window displays.
   
   
    

2. Create a start node if one does not already exist. This start node will respond to an application view event that you specify.

3. Double-click the start node. The Start Properties dialog box displays.
   
   
    

4. In the Description field, enter a name (optional).

5. Click Event.

6. In the Event list, select AI Start.

7. In the application view tree, navigate to and select the application view event.

   The application view tree organizes application view events by folder (example: EastCoast.Sales) and application view (example: CustomerManagement). All application view events are at the lowest level of the hierarchy.

8. If necessary, filter the event by entering a condition in the Condition field, or click the A + B button to display the Expression Builder dialog box.

   For information on setting up conditions and XPath expressions, see the WebLogic Process Integrator User Guide.

9. In the Event Document Variable list, select an XML variable. When the start node receives data from the application view event, this variable stores the data. If you do not care about the event data, skip this step.

   Note: If you need to examine the XML schema of the event document, click View Definition. The View Definition dialog box displays. Click Close when finished.
   
   

   
    

10. Click OK. The start node is saved.

Scenario 4: Setting Up an Event Node to Wait for
an Application View Event

In a workflow, you may want to create an event node that is triggered by an application view event. To set up an event node to respond to an application view event, edit the event node so it responds to an event of type AI Event, then select the appropriate application view event. If necessary, you can set up conditions on which to filter the application view event. After you save and activate the workflow, the workflow will progress to this event node, wait for a specified application view event, and continue processing.

Steps for Setting Up a Node to Wait for
an Application View Event

Follow these steps to set up an event node to be triggered by an application view event.

1. Within WebLogic Process Integrator Studio, open a template definition. The Workflow Design window displays.
   
   
    

2. Create an event node if one does not already exist. This event node will be triggered by a designated application view event.

3. Double-click the event node. The Event Properties dialog box displays.
   
   
    

4. In the Description field, enter a name (optional).

5. In the Type list, select AI Event.

6. In the application view tree, navigate to and select an application view event.

   The application view tree organizes application view events by folder (example: EastCoast.Sales) and application view (example: CustomerManagement). All application view events are at the lowest level of the hierarchy.

   Note: To check for newly saved application views and events at any time, click Refresh Tree.

7. If necessary, filter the event by entering a condition in the Condition field, or click the A + B button to display the Expression Builder dialog box.

   For information on setting up conditions and XPath expressions, see the WebLogic Process Integrator User Guide.

8. On the Event Properties dialog box, select an XML variable in the Event Document Variable list. When the event node receives data from the application view event, this variable stores the data. If you do not care about the event data, skip this step.

   Note: If you need to examine the XML schema of the event document, click View Definition. The View Definition dialog box displays. Click Close when finished.
   
   

   
    

9. On the Event Properties dialog box, click OK.