SDMetrics User Manual

SDMetrics - the UML design measurement tool

Contents > 8 Defining Custom Design Metrics and Rules > 8.3 Definition of Design Rules > 8.3.1 Violation

8.3.1 Violation

The "violation" procedure defines a condition expression for a model element. If the condition evaluates to true, the model element violates the rule and is reported.

For example, consider a rule stating that an abstract class should have child classes. The abstract class itself cannot be instantiated, so child classes are required for the class to become useful in the system. That rule can be defined as follows:

<rule name="NoSpec" domain="class" category="Completeness" severity="2-med">
  <description>Abstract class has no child classes, must be 
               specialized to be useful.</description>
  <violation condition="abstract='true' and NOC=0" />
</rule>

The condition expression condition checks if the class is abstract, and the number of children of the class (metric NOC) is zero.

The "violation" procedure has two attributes;

condition (required). Defines a condition expression (see Section 8.5.4 "Condition Expressions"); the rule is violated if the condition expression is "true".
value (optional). Specifies a metric expression that is evaluated for the violating model element. The value is displayed to the user and can be used to provide additional details how the model element violates the rule.

Section 8.3 "Definition of Design Rules"

Contents

Section 8.3.2 "Cycle"