Attributesàlists the attributes for the current item type. Item type attributes describe features of an item type. For example, if an item type is a purchase order requisition, then an item type attribute can be the requisition amount or the requisition ID. Type
Processeàlists the process activities or workflow process definitions for the current item type.
Notificationsàlists the notification activities associated with the current item type. A notification activity sends a message to a user or role. The message may prompt for a response or may simply provide information.
Functionsàlists the function activities associated with the current item type. A function activity represents a PL/SQL stored procedure that the Workflow Engine executes automatically. A function activity can also have activity attributes associated with it.
Eventsàlists the event activities associated with the current item type. An event activity represents a business event that the process receives, raises, or sends.
Messagesàlists the messages that a notification activity associated with the current item type can send to a user or role. A message can have message attributes associated with it.
Lookup Typesàlists the lookup types associated with the current item type. A lookup type has one or more values called lookup codes associated with it. A lookup type is a list of values that can be referenced by a message, or by a notification, function, or process as its possible result type.
1. Choose New from the File menu to create a workspace for your new process definition.
2. Create a new item type. The item type classifies the work item to be managed by the process
3. You can define item type attributes to fully describe your item type and have the activities in your process refer to these attributes for information.
5. Create new lookup types.
The Lookup Type maps to the Result Type of an activity. A Result Type is a list of possible results that an activity can have upon completion.
Lookup types can also be referenced by item type attributes, activity attributes, messages, or message attributes.
6. Create new messages.
If you wish to create a notification activity for your process, you
should first create the message that you want the notification activity to send.
You can drag a new message onto a notification activity in the navigator tree to assign the message to that activity.
7. Create a new process activity
The process diagram establishes the relationship of all the activities in your process.
8. Save your work by choosing Save or Save As from the File menu.
9. In a database accessible by your Oracle Workflow server, create the PL/SQL stored procedures called by your PL/SQL function activities. You can do this through SQL*Plus or the Oracle Procedure Builder.
Depending on the workflow process you wish to create, you need to define all or some of the following types of components to make up the process:
- Item Types
- Lookup Types
- Messages
- Activities
- Attributes
- Roles
Item Types
An item type is a classification of the components that make up a workflow process.
Often it makes sense to define an item type so that it describes the item being managed by your workflow process.
An Item Type usually congregates all the items used in the Workflow process.
For example, purchase order requisition can be an item type while a purchase order requisition identified by a particular ID number is an item of that item type.
Item Type Attributes
An item type attribute is a property associated with a given item type.
It acts as a global variable that can be referenced or updated by any activity within a process. An item type attribute often provides information about an item that is necessary for the workflow process to complete.
Applications as well as function activities can reference and set item type attributes using the Oracle Workflow Engine APIs.
These are also used to show any dynamic values in the notifications.
Attribute Types
There are ten attribute types, as shown below. The type determines what values are acceptable and how the attribute is used.
- Text: The attribute value is a string of text.
- Number: The attribute value is a number with the optional format mask you specify.
- Date: The attribute value is a date with the optional format mask you specify.
- Lookup: The attribute value is one of the lookup code values in a specified lookup type.
- Form: The attribute value is an Oracle Applications internal form function name and its optional form function parameters. This attribute type is not relevant for the standalone version of Oracle Workflow.
- URL: The attribute value is a Universal Resource Locator (URL) to a network location.
- Document: The attribute value is an attached document. You can specify the following types of documents in the default value field:
- PL/SQL document – A document representing data from the database as a character string, generated from a PL/SQL procedure.
- PL/SQL CLOB document – A document representing data from the database as a character large object (CLOB), generated from a PL/SQL procedure. The CLOB can contain plain text, HTML, an Adobe Acrobat Portable Document Format (PDF) document, a Microsoft Rich Text Format (RTF) document, or, if your database version is Oracle9i Database or higher, binary data encoded to base64.
- PL/SQL BLOB document – A document representing data from the database as a binary large object (BLOB), generated from a PL/SQL procedure. The BLOB can contain an image or other types of application files that are stored as binary data.
- Oracle Applications Framework region – In Oracle Applications, a JSP call to an Oracle Applications Framework region for inclusion in a notification message.
- Role: The attribute value is the internal name of a role. If a message attribute of type role is included in a notification message, the attribute automatically resolves to the role’s display name, eliminating the need for you to maintain separate attributes for the role’s internal and display names. Also when you view the notification from a web browser, the role display name is a hypertext link to the e–mail address for that role. To set a default value for the attribute, you must initially load roles from the database.
- Attribute: The attribute value is the internal name of another existing item type attribute that you want to maintain references to in a process.
- Event: The attribute value is a Business Event System event message in the standard WF_EVENT_T structure.
Activities
An activity is a unit of work that contributes toward the accomplishment of a process.
An activity can be a notification, a function, an event, or a process.
A notification activity sends a message to a workflow user. The message may simply provide the user with information or request the user to take some action.
A function activity calls a PL/SQL stored procedure or some external program to perform an automated function.
An event activity receives, raises, or sends a business event. A process activity is a modeled workflow process, which can be included as an activity in another process to represent a sub–process.
Notification Activity:
When the workflow engine reaches a notification activity, it issues a Send ( ) API call to the Notification System to send the message to an assigned performer. You define the message that the notification sends.
You specify the performer of a notification activity when you include the notification activity as a node in the process.
You can either designate the performer to be a specific role or an item type attribute that dynamically returns the name of a role.
Function Activity:
A function activity is defined by the PL/SQL stored procedure or external program that it calls. Function activities are typically used to perform fully automated steps in the process. As a PL/SQL stored procedure, a function activity accepts standard arguments and can return a completion result.
If you pass a parameter for the stored procedure, you can expose that parameter as an activity attribute. The activity attribute’s value can be set when you define that activity as a node in your process. Note that these activity attributes are available only to the current activity and are not global like item type attributes.
To Validate a Process Definition
- Choose Verify from the File menu to validate all process definitions for the currently selected data store.
- The following list is an example of some of the validation that the Verify command performs:
- Checks that a process has at least one Start and one End activity.
- Verifies that a process does not contain itself as a process activity.
- Restricts the same sub process from being used twice in a process.
- Validates that all possible activity results are modeled as outgoing transitions. If an activity completes with a result that is not associated with an outgoing transition, and a <Default> transition doesn’t exist for that activity, the activity enters an ’ERROR’ state.
- Validates that activity nodes marked as END nodes do not have any outgoing transitions.
- Validates that a notification activity’s result type matches the lookup type defined for the message’s ’RESULT’ message attribute.
- Verifies that message attributes referenced in a message body for token substitution exist in the message definition.
- For processes that reference objects from another item type, verifies that the requisite item attributes associated with the referenced item type exists.
Defining Procedures and Functions for Oracle Workflow
Oracle Workflow lets you integrate your own custom PL/SQL and Java procedures and functions at certain points in your workflow processes and in the Business Event System. To ensure that Oracle Workflow can properly execute your custom code, follow these standard APIs when developing your procedures and functions.
- Standard API for PL/SQL Procedures Called by Function Activities
- Standard API for Java Procedures Called by Function Activities
- Standard API for an Item Type Selector or Callback Function
- Standard APIs for ”PL/SQL” Document
- Standard API for an Event Data Generate Function
- Standard APIs for a Queue Handler
- Standard API for an Event Subscription Rule Function
The standalone version of Oracle Workflow provides a web–based interface called Launch Processes for you to test any workflow definition you define and save to the database. Launch Processes is accessible only to users belonging to the Workflow Administrator role.
Although you can run the Launch Processes web page against any Oracle Workflow database, we advise that you create a separate environment for testing purposes. To test a workflow definition, you should set up the following in your test environment:
- Define test users/roles. You can test against the users and roles predefined in the Oracle Workflow demonstration data model.
- If you are using the standalone version of Oracle Workflow and you plan to use the notifications web page to view notifications, you need to define your test users/roles in your web security system. Refer to your web server documentation for more information.
- If you plan to use e–mail to view notifications, you can send all notifications to a single test e–mail address by setting the Test Address configuration parameter when you configure a notification mailer. For more information, please refer to the Oracle Workflow Manager sections of the Oracle Applications Manager online help for Oracle Workflow embedded in Oracle Applications, or to the Oracle Workflow Manager sections of the Oracle Enterprise Manager online help for standalone Oracle Workflow.
To Test a Workflow Definition:
1. Use a web browser to connect to the Oracle Workflow home page.
2. Select the Launch Processes link to display the Launch Processes web page.
3. The Launch Processes page displays all the item type definitions stored in the database except the Oracle Workflow seeded item types: Wferror, Wfmail, and Wfstd. The internal name and description for each item type also appears. Select the item type that owns the workflow process definition you wish to test.
4. Use the Initiate Workflow web page to specify the details for the process you wish to launch. To initiate an instance of a workflow process, you need to specify:
- A unique item key for the process instance.
- A user–defined key that you want to use to identify the process.
- The name of the process to test.
- An optional process owner.
- Values for any item type attributes associated with the item type of the process.
Select OK. To initiate the workflow process, the Initiate Workflow web page calls the Workflow Engine CreateProcess and Startprocess APIs for the item type and item key specified. It also calls the Workflow Engine SetItemOwner and SetItemAttr APIs to set the process owner and all the item type attributes to the values specified.
5. The Workflow Monitor Activities List for your initiated process instance appears. The Activities List displays the status of the activities that have been executed. You can also select the View Diagram button to display the status of the process graphically in the Workflow Monitor.
6. If the process you are testing contains notifications, you can navigate back to the Workflow Home page and select the Find Notifications link to find the outstanding Notifications that require responses to complete the process. Alternatively, if you prefer to test the notification responses via e–mail, you can connect to the e–mail test account you specified for the notification mailer to respond to the outstanding notifications for your process.
Event Manager for Standalone Oracle Workflow
The Oracle Workflow Business Event System is an application service that leverages the Oracle Advanced Queuing (AQ) infrastructure to communicate business events between systems. The Business Event System consists of the Event Manager and workflow process event activities.
The Event Manager contains a registry of business events, systems, named communication agents within those systems, and subscriptions indicating that an event is significant to a particular system. Events can be raised locally or received from an external system or the local system through AQ. When a local event occurs, the subscribing code is executed in the same transaction as the code that raised the event, unless the subscriptions are deferred.
Events
A business event is an occurrence in an internet or intranet application or program that might be significant to other objects in a system or to external agents.
For instance, the creation of a purchase order is an example of a business event in a purchasing application. You can define your significant events in the Event Manager.
When an event occurs in an application on your local system, an event key must be assigned to uniquely identify that particular instance of the event. Then the event must be raised to the Event Manager.
Event Subscriptions
An event subscription is a registration indicating that a particular event is significant to a particular system and specifying the processing to perform when the triggering event occurs. You can define your event subscriptions in the Event Manager.
When you install Oracle Workflow, several default subscriptions to predefined Workflow events are automatically created. You can enable, disable, or copy these subscriptions to perform the event processing that you want.
To Create or Update an Event
1. Navigate to the Create Event page or to the Update Event page.
The Create Event page and the Update Event page are identical, except that the fields in the Update Event page are populated with previously defined information for the selected event.
2. Enter the internal name of the event in the Name field. The internal name is case–sensitive. The suggested format is a compound structure of identifiers separated by periods (.) as follows:
<Company>.<family>.<product>.<
3. Enter a display name for the event.
4. Enter an optional description for the event.
5. Select Enabled or Disabled as the event status. If you disable an event, its definition remains in the Event Manager for reference, but you cannot use the event in active subscriptions.
6. If you are defining an event that occurs on your local system, enter the generate functions for the event. A generate function is a PL/SQL procedure or Java API that can produce the complete event data from the event name, event key, and an optional parameter list. You can assign the event a PL/SQL generate function if the event has PL/SQL subscriptions, a Java generate function if the event has Java subscriptions, or both a PL/SQL generate function and a Java generate function if the event has both types of subscriptions.
To assign the event a PL/SQL Generate function; enter the PL/SQL procedure in the Generate Function field in the following format:
<package_name>.<function_name>
• To assign the event a Java Generate function; enter the Java API in the Java Generate Function field in the following format:
<customPackage>.<customClass>
7. Identify the program or application that owns the event by entering the program name in the Owner Name field and the program ID in the Owner Tag field.
8. Review the customization level for the event.
- Core – No changes can be made to the event definition. This level is used only for events seeded by Oracle Applications.
- Limit – The event status can be updated to enable or Disabled, but no other changes can be made to the event definition. This level is used only for events seeded by Oracle Applications.
- User – Any property in the event definition can be updated. This level is automatically set for events that you define.
Oracle Workflow provides several predefined events for significant occurrences within the Business Event System and other Oracle Workflow components. You can define subscriptions to these events for replication, validation, or other purposes. You can enable or disable many of the events if necessary.
Some predefined events are referenced by default subscriptions that are created automatically when you install Oracle Workflow. The subscriber for all the default subscriptions is the local system. You can enable, disable, or copy many of these subscriptions to perform the event processing that you want.
Some of the Predefined Workflow Events:
Event Definition Events
Event Created
Oracle Workflow raises this event whenever a new individual event or event group definition is created.
Internal Name
Status
Generate Function
Owner Name
Owner Tag
Customization Level
Event Updated
Oracle Workflow raises this event whenever an individual event or event group definition is updated.
Internal Name
Status
Generate Function
Owner Name
Owner Tag
Customization Level
Event Deleted
Oracle Workflow raises this event whenever an individual event or event group definition is deleted.
Internal Name
Status
Generate Function
Owner Name
Owner Tag
Customization Level Limit
System Definition Events
System Created
Oracle Workflow raises this event whenever a new system definition is created.
Internal Name
Status
Generate Function
Owner Name
Owner Tag
Customization Level
System Updated
Oracle Workflow raises this event whenever a system definition is updated.
Internal Name
Status
Generate Function
Owner Name
Owner Tag
Customization Level
Requisition Process and Approval Hierarchy :-
The Requisition process is an example of a workflow process that is initiated when you create a new requisition to purchase an item. The Requisition process is based on two tables that store approval hierarchy and spending authority information.
When you submit a requisition in this demonstration, the process sends a notification to the next manager in the approval hierarchy to approve the requisition. If the spending limit of the approving manager is less than the requisition amount, the process forwards the requisition to the next higher manager in the approval hierarchy until it finds a manager with the appropriate spending limit to approve the requisition. Each intermediate manager must approve the requisition to move it to the next higher manager. Once a manager with the appropriate spending limit approves the requisition, the process ends with a result of Approve.
The process can end with a result of rejected if:
- Any manager rejects the requisition.
- The requisition amount is greater than the highest spending limit.
- The requisition’s requestor does not have a manager.
Summary of the Requisition Approval Process
To view the properties of the Requisition Approval process, select the process in the navigator tree, then choose Properties from the Edit menu. The Requisition Approval process has a result type of Approval, indicating that when the process completes, it has a result of Approve or Reject (the lookup codes in the Approval lookup type associated with the Standard item type). This process activity is also runnable, indicating that it can be initiated as a top level process to run.
Oracle Workflow provides default error handling for both workflow processes and event subscription processing. The default handling is defined by error processes provided in a special item type called System: Error, and, for events, by a special subscription to the Unexpected event with a source type of Error. You can also choose to define your own custom error handling by creating custom error processes and subscriptions.
Error Handling for Workflow Processes
Errors that occur during workflow execution cannot be directly returned to the caller, since the caller generally does not know how to respond to the error. In fact, the caller may be a background engine with no human operator. Instead, Oracle Workflow lets you define the processing you want to occur in case of an error by specifying an error handling process when you create your workflow process in Oracle Workflow Builder.
At design time, you can assign an error handling process for a process, function, or event activity in the activity’s Details property page. You must specify the internal names of both the item type that owns the error handling process and the error handling process itself.
Oracle Workflow provides a special item type called System: Error, which contains error processes called Default Error process and Retry–only process that you can use for generic error handling in any of your processes. However, you cannot modify the error processes in the System: Error item type. If you want to incorporate functionality that is not available in these error processes, you should create your own custom error handling process in your own item type. An error process can branch based on error codes, send notifications, and attempt to deal with the error using automated rules for resetting, retrying, or skipping the failed activity.
At runtime, the Workflow Engine traps errors produced by function activities by setting a save point before each function activity. If an activity produces an unhandled exception, the engine performs a rollback to the save point, and sets the activity to the ERROR status.
For this reason, you should never commit within the PL/SQL procedure of a function activity. The Workflow Engine never issues a commit as it is the responsibility of the calling application to commit.
The Workflow Engine then attempts to locate an error process to run by starting with the activity which caused the error and then checking each parent process activity until an associated error process is located. If the Workflow Engine finds an error process, it launches that process to handle the error. If no error process is assigned for the running process, the Workflow Engine performs a rollback to the save point and sets the activity to the ERROR status, but no error process can be launched.
Unexpected Events
Oracle Workflow also uses the Default Event Error process to handle unexpected events. If an event is received from an external source, but the local system does not have any subscriptions to that event, the Event Manager automatically searches for subscriptions to the unexpected event with the source type External. Oracle Workflow provides a predefined External subscription to the unexpected event that sends the event message to the Default Event Error process.
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