Inside a stored procedure, you must use Workflow Engine APIs to communicate with the
Workflow Engine. All Workflow Engine APIs are stored in a PL/SQL package called
WF_ENGINE. The following is the list of Workflow Engine APIs present inside the
WF_ENGINE package.
Procedure Name
|
Description
|
Variable(I=Input,
O=Output)
|
AddItemAttr
|
Add
a new unvalidated runtime item attribute.
|
Item
type(I)
|
SetItemAttrText
|
Set
the value of a text item attribute.
|
Item
type(I)
Item key(I) Attribute name(I) New value(I) |
SetItemAttrNumber
|
Set
the value of a number item attribute.
|
Item
type(I)
Item key(I) Attribute name(I) New value(I) |
SetItemAttrDate
|
Set
the value of a date item attribute.
|
Item
type(I)
Item key(I) Attribute name(I) New value(I) |
GetItemAttrInfo
|
Get
type information about an item attribute.
|
Item
type(I)
Attribute name(I) Attribute type(O) Subtype(O) Format(O) |
GetActivityAttrInfo
|
Get
type information about an activity attribute.
|
Item
type(I)
Item key(I) Activity ID(I) Attribute name(I)
Attribute
type(O)
Sub-type(O) Format(O) |
SetItemParent
|
Set
the parent/master process for a detail process.
|
Item
type(I)
Item key(I) Parent item type(I) Parent item key(I) Parent context(I) |
SetItemOwner
|
Set
the owner of an item.
|
Item
type(I)
Item key(I) Owner(I) |
Set
the user-friendly identifier for an item.
|
Item
type(I)
Item key(I) User key(I) |
|
CB
|
Callback
function used by the Notification System to get and set process attributes,
and mark a process complete.
|
Action(I)
Context(I) Attribute name(I) Attribute type(I) Text attribute value(I,O) Number attribute value(I,O) Date attribute value(I,O) |
ProcessDeferred
|
Process
all deferred activities within the threshold limits.
|
Item
type(I)
Minimum threshold(I) Maximum threshold(I) |
ProcessTimeOut
|
Pick
up one timed-out activity and execute time-out transition.
|
Item
type(I)
|
ProcessStuckProcess
|
Pick
up one stuck activity, mark error status, and execute error process.
|
Item
type(I)
|
Background
|
Process
all current deferred and/or time-out activities within the threshold limits.
|
Item
type(I)
Minimum threshold(I) Maximum threshold(I) Process deferred flag(I) Process timeout flag(I) |
BackgroundConcurrent
|
Send
background process for deferred and/or time-out activities to the concurrent
manager.
|
Error
buffer(O)
Return code(O) Item type(I) Minimum threshold(I) Maximum threshold(I) Process deferred flag Process timeout flag |
CreateProcess
|
Create
a new runtime process for an item.
|
Item
type(I)
Item key(I) Root process(I) |
Begins
execution of the process.
|
Item
type(I)
Item key(I) |
|
SuspendProcess
|
Suspends
process execution. Outstanding notifications will be allowed to finish, but
activity transitions will not occur.
|
Item
type(I)
Item key(I) Process to suspend(I) |
AbortProcess
|
Abort
process execution. Outstanding notifications are cancelled. The process is
then considered complete, with a status specified by the result variable.
|
Item
type(I)
Item key(I) Process to abort(I) Result(O) |
ResumeProcess
|
Returns
a process to normal execution status. Used after a process is suspended.
|
Item
type(I)
Item key(I) Process to resume(I) |
BeginActivity
|
Determines
if the specified activity may currently be performed on the item.
|
Item
type(I)
Item key(I) Activity(I) |
CompleteActivity
|
Notifies
the Workflow Engine that an activity for an item has been completed.
|
Item
type(I)
Item key(I) Activity(I) Result(I) |
AssignActivity
|
Assigns
the user or role (performer) who will perform an activity.
|
Item
type(I)
Item key(I) Activity(I) Performer(I) |
HandleError
|
Resets
the process thread to the entered activity and begins execution again from
that point.
|
Item
type(I)
Item key(I) Activity(I) Command(I) Result(I) |
The last section of the stored procedure body is the EXCEPTION
block for exception handling. Any kind of exception handling is allowed in
PL/SQL. The only thing you must do is set the context information.
This is done
by the API calls
WF_CORE.CONTEXT(‘your_package_name’,
‘your_procedure_name’, itemtype, itemkey, to_char(actid), funcmode)
Your stored procedure can be in a PL/SQL package. The package
groups store procedures within the same category.
Review
Questions
1.
Which Work Engine API should you use to begin execution of an activity?
2.
Which Work Engine API should you use to get information about an item’s
attributes?
3.
For which functions can you use the Work Engine API Background?
4.
How do you notify the Work Engine about a completed activity?
