ValidationRule.TestExpression Property (Visio)

Gets or sets the logical expression that determines whether the target object satisfies the validation rule. Read/write.

Version Information

Version Added: Visio 2010

Syntax

expression .TestExpression

expression A variable that represents a ValidationRule object.

Return Value

String

Remarks

When you validate a diagram by calling the Validate method or by clicking Check Diagram on the Process tab, Microsoft Visio uses the test expression that you set as the TestExpression property value to determine whether the target object satisfies the validation rule. If the test expression evaluates to False, Visio generates a validation issue. If the test expression evaluates to True, no validation issue is generated.

Visio evaluates the test expression for target objects only when the value of the FilterExpression property of the ValidationRule object evaluates to True.

The syntax for the TestExpression property value is the same as that for a ShapeSheet expression. When you set the TestExpression property value, Visio does not check the syntax of the test expression. If the test expression is not syntactically correct, the evaluation of the expression fails during validation and Visio generates a validation issue at that time.

Example

The following Visual Basic for Applications (VBA) example shows how to use the TestExpression property to determine whether a particular shape target satisfies a validation rule.

' Add a validation rule to the document.
Set vsoValidationRule = vsoValidationRuleSet.Rules.Add(“Unglued2DShape”)
vsoValidationRule.Category = "Shapes"
vsoValidationRule.Description = "This 2-dimensional shape is not connected to
any other shape."
vsoValidationRule.Ignored = False
vsoValidationRule.TargetType = Visio.VisRuleTargets.visRuleTargetShape

' The validation function Is1D() returns a Boolean value that indicates 
' whether the shape is 1D (True) or 2D (False).
vsoValidationRule.FilterExpression = "NOT(Is1D())"

' The validation function GLUEDSHAPES returns a set of 
' shapes glued to the shape.
' It takes as input one parameter that indicates the direction of the glue.
' The direction values are equivalent to members of VisGluedShapesFlags:
' 0 = visGluedShapesAll1D, and 3 = visGluedShapesAll2D
' It takes as input one parameter indicating the direction of the glue.

' The validation function AGGCOUNT takes a set of shapes as its input, and 
' returns the number of shapes in the set.
vsoValidationRule.TestExpression = "AGGCOUNT(GLUEDSHAPES(0)) + AGGCOUNT(GLUEDSHAPES(3)) > 0"