The mapping between GIS and CIM classes and properties may depend upon the value of properties of source objects and upon relationships between source objects. Optional mapping directives in the mapping configuration govern these conditional transformations.

Classes and related classes

An <optional> tag within a cimClass definition in the mapping configuration specifies the characteristics of primary source objects and related objects transformed to the specified CIM class and its related classes in the CIM. In the following example, a PFCorrectingEquipment object in the GIS maps to a DeviceBank in the CIM only if it has related CAPACITORUNIT objects in the GIS.

 <cimClass name="cim:DeviceBank" primarySource="PFCorrectingEquipment">
 
  <optional>
   <HasRelatedObjects relatedClass="CAPACITORUNIT" atLeast="2" />
  </optional>

Properties

<option> and <default> tags within a cimProperty definition in the mapping configuration specify alternate derivations of a CIM property depending upon the value of fields in the source object and related objects. In the following example, the Equipment.isUnderground is set to true only if the source object in the GIS is PriUGElectricLineSegment.

  <cimProperty name="tdms:Equipment.isUnderground">
   <option>
    <SourceIs class="PriUGElectricLineSegment" />
    <constant value="true" />
   </option>
   <default>
    <constant value="false" />
   </default>
  </cimProperty>

Optional fields

When the CIM transformation does not find a field specified in a sourceField tag or if the value of the field is null, it ordinarily reports the missing data in a message log. The default and optional attributes can avoid these messages. When a sourceField tag includes both of these attributes, the sourceField operation returns the default value when data are missing and does not report the missing data in the message log.

The following expression yields the value of the GANGOPERATED field of a switch feature in the GIS. If the value of the field is Null in the GIS, it defaults to No in the CIM and no message indicating missing data appears in the message log.

 <sourceField name="GangOperated" default="No" optional="true" />