Transition Lines
Workflow activities can have multiple transitions from and to other activities, allowing different processing based on the activity action. Once multiple exit transitions are defined for an activity, it is necessary to define their behavior. This is done by editing the activity properties itself.
Activity Properties
Open the Activity Properties dialog box and navigate to the Transitions tab. Here the user can define the behavior of the transitions (both entering and exiting).
Entry
The Entry section contains all of the transitions currently defined as entry transitions for the activity. The order is not as important as the exiting transitions. However, it is very important that their behavior reflects the type of transitions that are being executed upstream of them. The initial behavior of the entry transitions is that the "All Entry Transitions must qualify" checkbox is not selected. This means that the first transition to qualify as an entry transition for an activity (which is also the exiting transition for another Activity) results in the Activity being executed.
All Entry Transitions must qualify: When this option is selected, the Workflow engine will search for all qualifying entry transitions and only execute the new activity if all qualifying transitions have qualified and have been executed. The activity will wait until all previous, required processing is complete.
Exit
This section contains all of the transitions currently defined as exit transition for the activity. They are in the order in which they were created initially and, if unchanged, will be tested in that order. Therefore, when executing transitions in sequence, it is important to define the order correctly.
In specified order, stop after first qualifying Transition: The default behavior for all activity transitions is to stop after the first qualifying transition. However, the user can also define the transitions as parallel. This means that each qualifying path will be executed. To do so, the user needs to uncheck this box in the Exit section. If the user wants every qualifying transition to be executed, this checkbox should be selected.
Move Up Arrow: After selecting a transition in the exit, the user can click the Move Up arrow and position the transition up one in the transition order.
Move Down Arrow: After selecting a transition in the exit section, the user can click on the Move Down arrow and position the transition down one in the transition order.
Execution of Transitions
When the Workflow Engine wakes up and processes a Workflow model instance, it takes the internal data and moves through the Workflow model following transitions that qualify and executes activities that qualify. When faced with a conditional path, the internal data is selected against the condition defined in the transition. If true, the path is executed to the next activity. If false, the transition is ignored.
When transitions are defined as sequential, only the first qualifying transition is executed. All other transitions exiting from the activity are ignored even if they qualify. When transitions are defined as parallel, every transition exiting from the Activity is executed. Only transitions that do not qualify are ignored.
When entering an Activity, the first qualifying transition is executed when the entry transitions are set to "All Entry Transactions must qualify." If not, then all must qualify since the activity will wait for them to execute before the activity itself can execute.
It is critical that the first transition is attached to the starting point, since that is how the model defines it. The last item the user attaches to is the ending point for the transition.
Transition Line Properties
Right-click a transition line to access the Transition Properties dialog:
General
The General tab holds the transition name and a general description of what the transition flow requirements are.
Conditions
The Conditions tab displays data elements and conditional operators that are used to formulate additional transitional conditions. Nodes/sections that make up a transition evaluation should be individually wrapped. To illustrate this, review the following evaluations:
Sample 1 (evaluation does not work):
(({Approve} = "A" OR { Approve }="B") AND ({User ID}="X" OR { User ID }="Y") AND ({Name}="John" OR {Name}="Mike"))
Sample 2 (evaluation works):
((({Approve} = "A") OR ({ Approve }="B")) AND (({User ID}="X") OR ({ User ID }="Y")) AND (({Name}="John") OR ({Name}="Mike")))
View
The View tab is basically a troubleshooting tool. When the user defines a transition on the Condition tab and selects the View tab, it shows what the criteria looks like as an XML Search path and inform the user whether the path is correctly formatted. If you have an instance currently attached, it will also tell you if the transition is true or false based on the internal data. If it is blank, verify an instance is attached. If there is, then the Condition created is malformed and needs to be reviewed until you get a “Selection is TRUE” or “Selection is FALSE” message in the bottom-left portion of the window.