The Policy Activity implements a rule set, which is a list of conditions and related actions in the IF..THEN..ELSE format. The activity allows extensive validation and similar without large workflow structures.
Clicking the RuleSetReference property … button opens the Select Rule Set Window shown below:
From this window rules can be created, edited, renamed or deleted, using the New…, Edit…, Rename…and Delete buttons respectively. Selecting New… or Edit… opens the Rule Set Editor window shown below. Selecting the … button on the RuleSetDefinition property will also open the window.
As well as an if, then and else property, each rule has a Priority property and a Reevaluation flag. Rules with higher Priority values are evaluated first, although how rules are reevaluated depends on the Chaining property. The three modes of behavior are below.
|Rules are evaluated in strictly linear fashion. Each rule would be evaluated once and in the order of priority.
|Explicit Update Only
|Rules are only evaluated when the method
Update("x") is called. This method gives total control of which rules cause re-evaluation.
|Any potentially effected Rules are revaluated.