3.8. Constraints

There are two types of constraints in business processes: code constraints and rule constraints.

Rule constraints do not have direct access to variables defined inside the process. However, it is possible to refer to the current process instance inside a rule constraint by adding the process instance to the working memory and matching for the process instance in your rule constraint. Logic is included to make sure that a variable processInstance of type WorkflowProcessInstance will only match the current process instance and not other process instances in the working memory. Note, it is necessary to insert the process instance into the session. If it is necessary to update the process instance, use Java code or an on-entry, on-exit, or explicit action in the process. The following example of a rule constraint will search for a person with the same name as the value stored in the variable name of the process:

processInstance : WorkflowProcessInstance()
Person( name == ( processInstance.getVariable("name") ) )
# add more constraints here ...

processInstance : WorkflowProcessInstance()
Person( name == ( processInstance.getVariable("name") ) )
# add more constraints here ...