ValidationRules.AddDependentProperty

Frazer posted on Thursday, September 03, 2009

Chapter 17 states:

ValidationRules.AddDependentProperty(StartedProperty, EndedProperty, true);

This call to the AddDependentProperty() method tells the business rules subsystem in CSLA .NET that any time the rules for the Started property are checked, the rules for Ended should be checked too, because the last parameter is true.

What happens if the last parameter is false? Am I correct that the this would cause the EndedProperty to be validated if the StartedProperty is changed but not vice versa?

Frazer

JonnyBee replied on Thursday, September 03, 2009

Hi,
Last perameter tells if this dependency is bidirectional, meaning:

false:
     when StartedProperty is Changed - check rules for EndedProperty also

true:
     when StartedProperty is Changed - check rules for EndedProperty also
     when EndedProperty is Changed - check rules for StartedProperty also

Do not add:
ValidationRules.AddDependentProperty(StartedProperty, EndedProperty, false);
ValidationRules.AddDependentProperty(EndedProperty, StartedProperty, false);
as this vill make an infinite loop. If bidirectional use
ValidationRules.AddDependentProperty(StartedProperty, EndedProperty, true);

/jonnybee