Required Rule
Can be used with: Task, Stage and Milestone
A plan item may be required, meaning that it has to reach an end-like state before the containing stage can complete. Whether a plan item is required can be specified by a required rule.
This rule is evaluated when the milestone, stage or task is instantiated and transitions to the state AVAILABLE
, and its result value of type boolean
is maintained throughout the remainder of the case instance. If this rule evaluates to true
, the plan item’s parent stage instance must not transition to COMPLETED
state unless the plan item is in the COMPLETED
, TERMINATED
or DISABLED
state. For example, a task that has not yet been worked on, i.e., is in state ENABLED
, prevents its containing stage to complete. If the rule is not present, then it is considered to be false
.
<planItem id="PlanItem_HumanTask_1" definitionRef="HumanTask_1">
<itemControl>
<requiredRule>
<condition>${true}</condition>
</requiredRule>
</itemControl>
</planItem>
<humanTask id="HumanTask_1">
</humanTask>
The specified expression ${true}
evaluates to the boolean value true
and means that the plan item is required.
For a plan item definition, the following XML can be used:
<planItem id="PlanItem_HumanTask_1" definitionRef="HumanTask_1"/>
<humanTask id="HumanTask_1">
<defaultControl>
<requiredRule>
<condition>${true}</condition>
</requiredRule>
</defaultControl>
</humanTask>
The rule specified in the humanTask
element is valid and individually evaluated for all plan items that reference it, here PlanItem_HumanTask_1
.
As with any expression, you can use case variables to determine the result of a required rule. The following snippet expresses that the plan item is required when a variable var
has a value greater than 100:
<requiredRule>
<condition>${var > 100}</condition>
</requiredRule>