Working with Workflow Components

 

The following sections describe how to use workflow components:

• Adding Workflow Components to a Workflow Diagram

• Deleting Components from a Workflow Diagram

• Defining Variables

• Defining Start

• Defining Dones

• Defining Decisions

• Defining Tasks

• Defining Events

• Using Joins (And/Or)

 

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Adding Workflow Components to a Workflow Diagram

After you first create a workflow template definition, the workflow toolbar and workflow drawing area are displayed on the right side of the WebLogic Process Integrator Studio main window.

By default, the drawing area already contains three shapes (components) that you must define: start, task, and done. If you will be adding a shape to an existing workflow diagram, right-click the workflow template definition in the folder tree and choose Open from the pop-up menu to open the workflow diagram.

Add new shapes to the diagram by clicking the shape in the toolbar, then clicking in the workflow diagram where you want to drop the shape. To identify icons to the toolbar, see Workflow Drawing Area in WebLogic Process Integrator Overview.

 

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Deleting Components from a Workflow Diagram

Delete a component from a workflow diagram in one of two ways:

• Select the shape in the drawing area, right-clicking it, and choose Delete from the pop-up menu.

• In the folder tree, right click the Start node and choose Delete from the pop-up menu.

A confirmation dialog box is always presented.

 

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Defining Variables

Not all workflow template definitions require variables. However, for those workflow template definitions containing processes that require variables, you should define these before you begin defining the workflow template definition. You can also add these variables as you create the workflow template definition.

Process variables have a workflow-global scope. That is, a single variable instance is shared by all objects within a workflow template definition instance. Process variables are therefore defined at the workflow template definition level in the folder tree and are referred to as workflow variables.

Each workflow template definition can have a set of variables associated with it. A variable is typically used to store application-specific information required by the workflow at run time. Variables are created and assigned values largely to "control" the logical path through a workflow instance; the same workflow template definition is instantiated multiple times and can be traversed in different ways if the flow contains decision nodes, which test workflow variable values to branch to either the next True or next False within the workflow.

Defining Variables

To define a variable:

1. In the folder tree, right-click Variables under the appropriate workflow template definition, and choose New Variable to display the Variable Properties dialog box.

   Figure 4-1 Variable Properties Dialog Box

   

2. Complete the following fields:

   • Name — Enter a meaningful name for the variable, such as ItemNumber, in the Name field.

   • Type — Variable type: String, Integer, Double, Date, Boolean, Complex Object, XML.

   • Parameter — Input or Output. For Input, choose whether the parameter is a mandatory one. The parameter is defined for workflow variables that have a called start node. These parameters are passed to (Input) and returned from (Output) a sub-workflow.

   • Notes — A free-form text field that can be used to make notes for the variable.

Updating Variables

To update an existing variable:

1. Right-click an existing variable in the folder tree and choose Properties from the pop-up menu. The Variable Properties dialog box is displayed.

2. Make changes to the variable as needed, and click OK.

Locating Variables in the Workflow

To see where a variable is used within the workflow, right-click the variable in the folder tree and choose Usage from the pop-up menu. This displays the Variable Usage dialog box.

Figure 4-2 Variable Usage Dialog Box

The Variable Usage dialog box lists the nodes within a workflow template definition in which the selected variable is used and the value assigned to that variable. Variables can be used in all workflow nodes except joins and dones.

In the preceding figure, the Confirm variable is used in the Confirm Order task and has a value of :Confirm="yes".

The dialog box contains the following buttons:

• Update — Update the selected action. Opens the action dialog box to allow the variable expression to be edited.

• Delete — Delete the selected action.

• OK — Close the Variable Usage dialog box.

Variable Conversion Rules

The following table details the implicit conversions that are handled automatically by WebLogic Process Integrator between different variable types.

Table 4-1 Variable Conversions

Value Converted To	String	Integer	Double	Date	Boolean	XML	NodeList 1
String	X 2	X 3	X 4	X 5	X 6	X 7	X 8
Integer	X 9	X 10	X 11	NS	X 12	NS	X 13
Double	X 14	X 15	X 16	NS	X 17	NS	X 18
Date	NS	NS	NS	X 19	NS	NS	NS
Boolean	X 20	X 21	X 22	NS	X 23	NS	X 24
XML	X 25	NS	NS	NS	NS	X 26	X 27

Note: NS is Not Supported.

The following are notes relating to certain conversions in the preceding table:

1. org.w3c.dom.NodeList, which is typically the output of Xpath() function. The Xpath() function also returns Double, Boolean, String, and Integer types.

2. As it is

3. Java Integer.toString() output

4. Java Double.toString() output

5. Java Date.toString() output

6. Java Boolean.toString() output: "true" and "false"

7. DOM serializing

8. DOM serializing

9. An ILLEGAL_CONVERSION warning WorkflowException is thrown if parsing cannot occur (NumberFormatException).

10. As it is

11. Double's Integer value

12. 1 if true, 0 if false

13. DOM serialized to string, then convert to Integer (See note 9.)

14. An ILLEGAL_CONVERSION warning WorkflowException is thrown if parsing cannot occur (NumberFormatException).

15. Integer's Double value

16. As it is

17. 1.0 if true, 0 if false

18. DOM serialized to string, then convert to Double (See note 14.)

19. As it is

20. True if string value is "true", "t", "1"; false if string value is "false", "f", "0". Any other string value throws an ILLEGAL_CONVERSION warning WorkflowException.

21. False if Integer value is 0, true if any other value

22. False if Double value is 0, true if any other value

23. As it is

24. DOM serialized to string, then convert to Boolean (See note 20.)

25. DOM parsing to a XML document element (not simply a node, which means when it is dumped back to a String, it will have XML header similar to the following: <?xml version="1.0" encoding="UTF-8"?>). An ILLEGAL_CONVERSION warning WorkflowException is thrown if DOM parsing cannot occur.

26. As it is

27. DOM serialized to string, then convert to XML node (See note 25.)

 

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Defining Start

Every workflow has at least one start shape that indicates the beginning of the workflow. The first node after the start will be the first activated node of the workflow, which can be a task, decision, or event.

Specifying Multiple Starts

You can specify more than one start shape, if more than one simultaneous path through the workflow is to be started. For example, when you want two streams of work to start at the same time within a single workflow, you can define two starts within the workflow.

These two streams of work can be started at simultaneously, if they have the same triggering event and are both marked as manual starts or timed starts set to the same time. Otherwise, the two streams can be started separately with each start being an alternate way of starting the workflow.

The benefit to the ability to specify more than one start is visual access to both streams of work within the same workflow and these streams of work can share the same variables. You have the flexibility to take a portion of a workflow and starting it in a different manner or at a different time within the workflow.

Note: If no Start shape is specified, then no task activation can occur in the workflow.

You specify the triggering properties of a workflow in the start node. If a workflow contains multiple starts, each start can have its own triggering method and start independently.

Defining a Start Node

To define a Start shape:

1. Display or add the Start shape as described in Adding Workflow Components to a Workflow Diagram.

2. Double-click the Start shape to display the Start Properties dialog box.

   Figure 4-3 Start Properties Dialog Box

   

3. The Description field by default contains the name Start. Modify this name as needed to create a unique, identifiable name.

4. Select a workflow triggering method:

   • Event — If you choose this triggering option, complete the procedure in Defining a Workflow Event Trigger in Understanding WebLogic Process Integrator Events and XML Documents.

   • Timed — If chosen, the following fields appear. Define an exact date and time when the workflow will start.

     Figure 4-4 Timed Option

     

     Start Date Expression — Enter the expression that defines the start date for the workflow; you must use a date function, such as Date or DateAdd, in this expression. Refer to Using Expression Components in Using Expressions and Conditions.

     Reschedule — Reschedule the timed workflow. If you define this option, the workflow will be rescheduled according to the incremental values entered here.

     Calendar — Select the business calendar that is used to evaluate the start date.

     Start Organization — Select a Start Organization from the drop-down list containing those organizations already defined within WebLogic Process Integrator. When the start node is an event or timed type, you must specify the organization for which the workflow instance will be started, because you can start the same workflow template definition for different organizations.

     If you want to define the Start Organization using an SQL expression, select the Workflow Expression option. The Expression Builder is displayed; use this to enter an expression that will be evaluated at run time and become the name of an organization. The expression can be either a string that specifies the organization (case sensitive) or an expression using information passed in the XML document.

     Note: Expressions are built using structured query language (SQL). If you know the syntax of the expression you want to use, you can type the expression directly in the field. Alternatively, click the A+B button to display the Expression Builder dialog box. The Expression Builder helps you construct an expression, which is made up of functions, operators, literals, and variables. For more information on constructing expressions, see Using Expressions and Conditions.

   • Manual — If chosen, the workflow must be started manually by an end user from the WebLogic Process Integrator worklist. This type of start requires that the end user know the specific business conditions that determine when to start the workflow. You might create a manual start when you cannot create a trigger that captures all required conditions.

   • Called — If chosen, the workflow is called by another workflow using the Start Workflow action. Refer to Start Workflow in Using Actions, for more information on this action.

5. Complete or view the fields on the tabs:

   • Variables — Assign workflow variables to be initialized at the start of your workflow. For example, you might have a counter in your workflow that you wish to take the value of 1 at the start of the workflow; you can assign a variable specifying that the counter takes the value of 1 upon initialization of the start node. Clicking Add displays the following dialog box where each variable can be assigned an XML Expression. The variables in the pull-down list are those defined in the Variables Properties dialog box. (See Defining Variables.)

     Note: Expressions are built using structured query language (SQL). If you know the syntax of the expression you want to use, you can type the expression directly in the field. Alternatively, click the A+B button to display the Expression Builder dialog box. The Expression Builder helps you construct an expression, which is made up of functions, operators, literals, and variables. For more information on constructing expressions, see Using Expressions and Conditions.

     Figure 4-5 Workflow Variable Assignment Dialog Box

     

   • Next — Displays a list of all task, decision, join, and done nodes in the current workflow. An start can have one or more successors. Select the node(s) that will serve as the next activated node(s) in the workflow when the start node is initiated.

   • Actions — Displays the list of all actions to be performed when the start node is initiated. Click Add to display the list of available actions. Refer to Using Actions, for further details on selecting actions.

     Figure 4-6 Add Action Dialog Box

     

   • Notes — A free form text field for recording notes about the start.

 

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Defining Dones

A done shape represents the point within the workflow where the process completes. Once a done node is reached in the workflow, the running instance of the workflow is marked done, regardless of whether all the done nodes have been reached or not.

You can specify any number of done shapes in a workflow. If a workflow can exit from various points, you have the option of placing separate done nodes wherever needed.

To define a done:

1. Add or view a done shape as described in Adding Workflow Components to a Workflow Diagram.

2. Double-click the done shape or right-click it in the folder tree and choose Properties to display the Done Properties dialog box.

   Figure 4-7 Done Properties Dialog Box

   

3. Complete or view the fields:

   • Actions — Displays the list of all actions to be performed when the Done node is reached. Click Add to display the list of available actions. Refer to Using Actions, for further details on selecting actions.

   • Notes — A free form text field for recording notes about the done.

 

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Defining Decisions

The workflow can use any number of decision shapes. Each decision shape contains a condition that is evaluated when a transition to that decision node occurs. The result is either true or false, with subsequent flow of control passed to the subsequent task, decision, event, and join or done node(s). Additionally, it is possible to specify actions to be executed on both a True and a False evaluation of the condition. (If the condition is verified, it is True. If it is not, it is False.)

To define a decision:

1. Add or view a Decision shape as described in Adding Workflow Components to a Workflow Diagram.

2. Double-click the Decision shape or right-click it in the folder tree and choose Properties to display the Decision Properties dialog box.

   Figure 4-8 Task Properties Dialog Box

   

3. Complete the following fields:

   • Condition — Specify the conditional expression to evaluate at run time. When the decision is activated in a running workflow (that is, a transition is made to the decision shape), this conditional expression is evaluated.

     Note: Expressions are modeled on structured query language (SQL). If you know the syntax of the expression you want to use, you can type the expression directly in the field. Alternatively, click the A+B button to display the Expression Builder dialog box. The Expression Builder helps you construct an expression, which is made up of functions, operators, literals, and variables. For more information on constructing expressions, see Using Expressions and Conditions.

   • Actions — A tabbed display showing the list of actions to be executed if the specified condition is evaluated and the result is either false or true. The tab that appears foremost indicates which of the two lists (False or True) is currently displayed. See Using Actions, for a description of how to specify actions.

     False — Actions defined in this tab are executed if the condition evaluates to false (is not verified).

     True — Actions defined in this tab are executed if the condition evaluates to true (is verified).

4. Provide or view information in the tabs of the Properties section of the dialog box.

   • Next True — A list of all nodes in the current workflow. On a True evaluation of the specified Decision condition, the indicated item(s) will be the next activated in the flow. If you have defined a sequence to the shapes on the workflow diagram using connector lines, a check mark (¸) is displayed next to any successor shapes. Place a check mark beside any other shape you want to execute after a true evaluation of this decision. A connector line is automatically drawn on the workflow diagram. You can also create the true connection from the decision shape to a subsequent node by clicking the connector on the drawing area toolbar, clicking in the drawing area to drop.

   • Next False — A list of all nodes in the current workflow. On a False evaluation of the specified decision condition, the indicated item(s) will be the next activated in the flow. If you have defined a sequence to the shapes on the workflow diagram using connector lines, a check mark (¸) is displayed next to any successor shapes. Place a check mark beside any other shape you want to execute after a false evaluation of this decision. A connector line is automatically drawn on the workflow diagram. The false connection from the decision shape to a subsequent node can also be created by clicking the connector on the drawing area toolbar, clicking in the drawing area to drop it, and then moving its end points to make the connections.

   • Decision Notes — A free-form text field that can be used to make comments or notes for the Decision shape.

   • Action Notes — A read-only text field showing the defined notes for the action selected on the left-hand side of the dialog box.

 

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Defining Tasks

A workflow contains a series of tasks, each of which represents a discrete activity to be performed automatically by the WebLogic Process Integrator server or by a workflow user. The task behavior is determined by various task properties and by the task actions that define the processing to be performed as certain task events occur.

To define a task:

1. Display or add a task as described in Adding Workflow Components to a Workflow Diagram.

2. Double-click the task shape or right-click the task in the folder tree and choose Properties to display the Task Properties dialog box.

   Figure 4-9 Task Properties Dialog Box

   

3. Complete the following fields:

   • Task Name — Enter a meaningful name, such as ConfirmOrder. This value is used primarily in the worklist, but it is visible from the various WebLogic Process Integrator monitoring reports. The system automatically assigns a unique temporary name to new tasks (in the form of Task n, where n is a number).

   • Priority — Select Low, Medium, or High priority. This field is displayed in the worklist and can be used to sort the worklist by priority. The initial default value is Medium.

   • Actions — Tabbed display of four separate lists of actions for the task, corresponding to the task events. See Using Actions, for a description of how to specify actions. A task responds to an event at run time by executing the associated actions; actions defined within these task events are guaranteed to occur in sequence. The four task events are as follows:

     Created — The workflow is started and all tasks in the workflow are created.

     Activated — The workflow diagram indicates a task transition has occurred, usually as a result of another task being marked as done or a decision being evaluated. The task is available to be performed.

     Executed — An event has occurred that causes this task to be executed. This usually occurs when a user selects a task in the worklist and executes it, often by double-clicking the task, or when an Execute Task action is performed for that task.

     Marked Done — The task has been completed. This event occurs usually in response to the execution of a Mark Task as Done action.

     To display the list of actions for a different event, select the appropriate tab.

4. View or provide information on the following tabs:

   • Next — A list of all nodes in the current workflow. When this task is marked done, the selected item(s) will be the next activated in the flow. If you have defined a sequence to the shapes on the workflow diagram using connector lines, a check mark (¸) is displayed next to any successor shapes. Place a check mark beside any other shape you want to execute after this task is complete. A connector line is automatically drawn on the workflow diagram. You can also create the connection from the task shape to a subsequent shape by dragging the Next connector from the workflow toolbar, dropping it on the workflow drawing and then moving its end points to make the connections.

   • Permissions — Specifies how a task instance can be modified or processed once the workflow is started. Select a permission to activate it. The permissions can be selected in any combination. Five different permissions are maintained for each task:

     Mark done without executing — Allows users to mark the task as having been done without actually executing it.

     Re-execute if marked done — Allows users to re-execute the task when it is already marked as done.

     Unmark if marked done — Allows users to change the status of the task back to not done when the task is marked as done. (If a user marks a completed task as not done, the task status is set to Active; it does not, however, reverse the effects of any actions that have been executed.)

     Modifiable — Allows users to change the properties of an existing task from the worklist.

     Re-assignable — Allows users to reassign the task to another user.

   • Task Notes — A free-form text field where you can make comments or notes for the task shape.

   • Action Notes — A read-only text field showing the defined notes for the action selected on the left-hand side of the dialog box.

 

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Defining Events

A workflow event shape represents a notification node. The workflow waits for an XML message to trigger the event. Upon that trigger, actions defined within the event can be executed and/or workflow variables can be set.

To define an event:

1. Display or add a task as described in Adding Workflow Components to a Workflow Diagram.

2. Double-click the event shape or right-click it in the folder tree and choose the Properties command to display the Event Properties dialog box.

   Figure 4-10 Event Properties

   

3. To define the event, follow the procedure in Using the XML Notification: The WebLogic Process Integrator Event in Understanding WebLogic Process Integrator Events and XML Documents.

 

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Using Joins (And/Or)

The possibility of multiple paths being active in the same workflow gives rise to the issue of path joining. There are two types of joining: AND joining and OR joining.

How Joins Work

AND joining melds multiple separate paths of control back into a single path, synchronizing them such that control does not continue until all paths converge. This type of join derives its name from the fact that control continues when the AND of all inputs is true. That is, when Path 1 and Path 2 and Path 3 ... etc. are all present, then control proceeds. An AND join will reset itself immediately after it is activated, in order to allow a looping process.

OR joining allows multiple path threads to enter and traverse down the same line of control within the workflow. In this case, the threads do not meld; the nodes along this part of the flow are executed multiple times, once for each thread control passing through it. This type of joining derives its name from the fact that control passes to the next node when the OR of its inputs is true. That is, if Path 1 or Path 2 or Path 3 ... etc. is present, then control proceeds.

An OR join can only be activated once. This avoids the multiple occurrence of actions and events succeeding the OR, which can happen by the completion of the various predecessors of the join. However, this single activation prevents a flow from looping when an OR join is defined, as the flow stops the second time at the OR join.

Use AND and OR joins to link task, decision, and event shapes and thus control the transition coming to the join and flowing from it.

Defining a Join

To define a join:

1. Display or add a join as described in Adding Workflow Components to a Workflow Diagram.

2. Double-click the join shape or right-click it in the folder tree and choose Properties to display the Join Properties dialog box.

   Figure 4-11 Join Properties Dialog Box

   

3. Complete or view the fields as follows:

   • Specify whether the join is an AND or OR.

   • Next — Displays a list of all nodes in the current workflow. A join can have one or more successors. Select items in this list to activate them in the flow after the join is satisfied.

   • Join Notes — A free form text field to record any specific notes or comments about the join.