Initializes a new instance of the RuleObjectExistsAttribute class.
public RuleObjectExistsAttribute( string id, string targetContextIDs, string criteria, string messageTemplate )
Public Sub New( id As String, targetContextIDs As String, criteria As String, messageTemplate As String )
A string value representing the current rule identifier. You can pass an empty value as the id parameter. An appropriate identifier will begenerated automatically, and set for the ID property of the Validation | Rules | Rule node in the Application Model.
A string value that specifies a list of identifiers of the contexts when the current rule should be checked. This value is set for the RuleBaseAttribute.TargetContextIDs property.
A string value representing the criteria that must be satisfied by the target type objects.
A string value representing information defining the current rule. This value is set for the RuleBaseAttribute.CustomMessageTemplate property.
If you are going to use a default message template for the rule, use a constructor without the messageTemplate parameter.
The common rules of writing a criteria are described in the Ways to Build Criteria topic. In addition, you can use the following construction: "PropertyName = '@PropertyName'" (the operator is optional). @PropertyName represents a parameter that is set to the value of the PropertyName property of the currently validated object, when the rule is checked.