8.1 Definition of Metrics

<metric name="metricname" domain="metricdomain" category="metriccategory"
  internal="true/false" inheritable="true/false"> 
  <description>Description of the metric.</description>
  <'metric definition' ...>
</metric>

• name (required): the name of the metric. The metric names serve as column names in the output tables, and are also used to reference the metrics.
• domain (required): the type of element for which the metric is defined (e.g., package, class, operation).
• category (optional): describes the structural property the metric measures, e.g., "size", "export coupling", "cohesion", etc. There is no preconceived classification of categories in SDMetrics, you can define any categories you deem fit. This attribute only serves documentation purposes and does not impact the calculation of the metric in any way.
• internal (optional): indicates if the metric is internal. An internal metric is not shown in the output tables. It is rather a "helper" metric that is used to define some other metrics, but by itself is probably not useful. Set the attribute value to "true" to mark a metric as internal. When omitted, the attribute defaults to "false".
• inheritable (optional): indicates if the metric should also be defined for all subtypes of the "domain" element type. When you set the attribute value to "true", all direct and indirect subtypes of the domain "inherit" the metric definition, and the metric will be calculated for all subtypes, too. When omitted or set to "false", the metric definition is not passed on to subtypes.

Following the metric tag is an optional description of the metric, which will be shown in the measurement catalog (see Section 4.13 "The View 'Catalog'"). Section 8.6 "Writing Descriptions" explains how to write metric descriptions.

Following the description is an XML element that defines the calculation procedure for the metric. We describe each calculation procedure in detail in the following subsections.