Extensibility with Custom Properties
Note: There is a newer version of this specification see VEC 2.0.2
CustomProperties have been introduced to the VEC as the dedicated extension mechanism. All subclasses of ExtendableElement class are extendable by providing the possibility to define CustomProperties. CustomProperties allow the definition and transport of almost any piece of data in an embedded way, for which the VEC does not define a different means of expression.
If a VEC entity shall be extended with multivalued property this is done by adding multiple CustomProperties with the same propertyType. In cases where a custom property value consists of a tuple of other values, a ComplexProperty can be used. This is especially useful, when the respective property is multivalued. An example for such a property / structure that is already represented in the VEC are Colors where each color consists of a referenceSystem and a key in that referenceSystem and each entity can have multiple colors (the same color in different reference systems).
Note: According to this data format specification it is strictly forbidden to store data within CustomProperties for which the VEC knows a special predefined way of expression. VEC-Files that do not obey to this rule are not compliant to this data format specification.
Note: Please refer to the detailed class description for information about which elements inherit from ExtendableElement.