List Types

Overview

A list type is a simple type that allows for values to be repeated, separated by a space.

In NIEM, multiple values are typically represented by a property that occurs multiple times. Lists are provided to represent larger sets of data values, such as readings from a sensor.

Modeling

Name

The name of a list type should end with the representation term “ListSimpleType”.

XML

Instance example

<nc:MeasureDecimalValueList>1.1 1.1 1.1 1.2 1.1 1.1 1.3 1.3 1.4 1.3 1.3 1.3 1.2 1.2 1.2 1.2 1.2 1.3 1.3 1.2 1.3 1.3 1.3</nc:MeasureDecimalValueList>

Schema example

The following example shows the declarations of

a simple list type,
a complex type with simple content based on the simple list type, and
an element with the complex type.

<xs:simpleType name="DecimalListSimpleType">
  <xs:annotation>
    <xs:documentation>A data type for a white space-delimited list of decimal.</xs:documentation>
  </xs:annotation>
  <xs:list itemType="xs:decimal"/>
</xs:simpleType>

<xs:complexType name="DecimalListType">
  <xs:annotation>
    <xs:documentation>A data type for a white space-delimited list of decimal.</xs:documentation>
  </xs:annotation>
  <xs:simpleContent>
    <xs:extension base="nc:DecimalListSimpleType">
      <xs:attributeGroup ref="structures:SimpleObjectAttributeGroup"/>
    </xs:extension>
  </xs:simpleContent>
</xs:complexType>

<xs:element name="MeasureDecimalValueList" type="nc:DecimalListType" substitutionGroup="nc:MeasureValueListAbstract" nillable="true">
  <xs:annotation>
    <xs:documentation>A list of decimal measurement values, all using the same measurement method/device and of the same units.</xs:documentation>
  </xs:annotation>
</xs:element>

Schema template

The following is a template for the declaration of a simple list type:

<xs:simpleType name="NAMEListSimpleType">
  <xs:annotation>
    <xs:documentation>A data type for a list of ...</xs:documentation>
  </xs:annotation>
  <xs:list itemType="BASE-TYPE"/>
</xs:simpleType>

JSON

JSON guidance for list types is not yet available.

References

Rule	Applicability	Title
NDR 9-15	REF, EXT	No list item type of xs:ID
NDR 9-16	REF, EXT	No list item type of xs:IDREF
NDR 9-17	REF, EXT	No list item type of xs:anySimpleType
NDR 9-18	REF, EXT	No list item type of xs:ENTITY
NDR 11-4	REF, EXT	Use lists only when data is uniform
NDR 11-5	REF, EXT	List item type defined by conformant schemas