ClassDefinition object

A ClassDefinition object is a PowerBuilder object that provides
information about the class definition of a PowerBuilder object. You can
examine a class in a PowerBuilder library or the class associated with an
instantiated object.

All the properties are read-only. You cannot change the class
definition using the ClassDefinition object. The ClassDefinition object
has no events.

The ClassDefinition object lets you check:

The name of the class

The library the class was loaded from

The class definition of its ancestor, if any

The class definition of its parent or container object, if
any

Whether the class is autoinstantiated

Whether the class is a system class (defined by PowerBuilder) or
a user-defined object (defined in a PowerBuilder PBL)

The classes the object contains, such as the controls contained
in a window

The variables and scripts defined in the class

Class names are always reported as lowercase, as you see them in the
Browser.

Global functions and variables

Call FindFunctionDefinition to get a ScriptDefinition object
describing the global function. Global variables are included in the
VariableList array in the ClassDefinition object for the Application
object.

Properties

ClassDefinition property

Datatype

Description

Ancestor

ClassDefinition

An object that represents the ancestor class.
Ancestor is NULL when the ClassDefinition is describing
PowerObject.

Category

TypeCategory

Specifies whether the type is simple, enumerated,
or a class or structure. For a class definition, the value is
ClassOrStructureType!.

ClassDefinition

PowerObject

An object of type PowerObject containing
information about the class definition of the object or
control.

DataTypeOf

String

The system class name of the object. DataTypeOf is
a string representation of a value of the Object enumerated
datatype. Values are lowercase with no exclamation point. Sample
values include:

window

string

any

dropdownlistbox

For objects you have defined, the datatype
is the system class from which your object is
inherited.

IsAutoinstantiate

Boolean

Indicates whether the class is an autoinstantiated
class.

IsStructure

Boolean

Indicates whether the class is a
structure.

IsSystemType

Boolean

Indicates whether the class is a system class —
that is, one of the classes defined within PowerBuilder as
opposed to a class defined in a PBL by a user.

IsVariableLength

Boolean

Specifies whether the datatype has a fixed size.
Values are:

TRUE — The datatype is variable length,
meaning the datatype is a string, any, blob, or unbounded
array.

FALSE — The datatype is a fixed
length.

IsVisualType

Boolean

Indicates whether the class is a visual
(displayable) or non-visual type. Values are:

TRUE
— The class is visual, for example, a window or a
control.

FALSE — The class is non-visual, for
example, a class user object or a simple
datatype.

LibraryName

String

The fully qualified name of the library the class
was loaded from.

Name

String

The name of the class. For a nested class, the name
is returned in the form of
libraryEntryName`className.

NestedClassList[ ]

ClassDefinition

An unbounded array of objects representing the
nested classes and local structures for the
object.

The array is empty if there are no nested
classes. Call the UpperBound function to find out the number of
nested classes.

ParentClass

ClassDefinition

An object that represents the parent class that
this class is nested within. The value is NULL if the class is
not a nested class.

ScriptList[ ]

ScriptDefinition

An unbounded array of objects representing the
scripts implemented or defined in the collapsed class
hierarchy.

The array is empty if there are no
scripts. Call the UpperBound function to find out the number of
scripts.

VariableList[ ]

VariableDefinition

An unbounded array of objects representing the
properties or shared variables in the collapsed class
hierarchy.

The array is empty if there are no
variables. Call the UpperBound function to find out the number
of variables.

Functions

ClassDefinition function	Datatype returned	Description
ClassName	String	Returns the class of the object.
FindMatchingFunction	ScriptDefinition	Finds a function that matches the specified name and argument list.
GetContextService	Integer	Creates a reference to a context-specific instance of the specified service.
GetParent	PowerObject	Returns a reference to the name of the parent object.
TypeOf	Object	Returns the type of the object.

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Powerbuilder Documentation 2019

August 21, 2023

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ClassDefinition object – PB Docs 2019