Using Caché Objects - InterSystems Documentation

Transient
Property Visibility
Specifies that the property is not stored in the database. By default, properties are
not transient. Subclasses inherit the value of the Transient keyword and cannot
override it.
Type
Specifies the name of the class associated with the property, which can be a data type
class, a persistent class, or an embeddable class. By default, the type of a property is
%String. Subclasses inherit the value of the Type keyword.
7.2 Property Visibility
Properties may be specified as being public or private. If they are public, they can be accessed
anywhere. If they are private, they can only be accessed by instance methods of the object
to which they belong.
Note:
Methods which are declared as classmethods do NOT have access to properties
declared to be private, even if they have a reference to an object of the class they are
declared in. Private properties are only accessible from within instance methods of
the class..
In Caché, private properties are always inherited and visible to subclasses of the class that
defines the property. Other languages often call these protected properties.
7.3 Property Behavior
Properties have a number of methods associated with them automatically. These methods are
not inherited via standard inheritance. Rather, they use a special property behavior mechanism
to generate a series of methods for each property.
Each property inherits a set of methods from two places:
• A %Property class that provides certain built-in behavior, such as Get, Set, and validation
code.
• The data type class of the property's data type, if it is a data type property. Many of these
methods are method generators.
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