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.
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ClassDefinition property |
Datatype |
Description |
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|---|---|---|---|---|---|---|
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Ancestor |
ClassDefinition |
An object that represents the ancestor class. Ancestor is NULL when the ClassDefinition is describing PowerObject. |
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|
Category |
TypeCategory |
Specifies whether the type is simple, enumerated, or a class or structure. For a class definition, the value is ClassOrStructureType!. |
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ClassDefinition |
PowerObject |
An object of type PowerObject containing information about the class definition of the object or control. |
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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:
For objects you have defined, the datatype is the system class from which your object is inherited. |
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IsAutoinstantiate |
Boolean |
Indicates whether the class is an autoinstantiated class. |
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IsStructure |
Boolean |
Indicates whether the class is a structure. |
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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. |
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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. |
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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. |
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LibraryName |
String |
The fully qualified name of the library the class was loaded from. |
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|
Name |
String |
The name of the class. For a nested class, the name is returned in the form of libraryEntryName`className. |
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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. |
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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. |
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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. |
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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. |
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ClassDefinition function |
Datatype returned |
Description |
|---|---|---|
|
String |
Returns the class of the object. |
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|
ScriptDefinition |
Finds a function that matches the specified name and argument list. |
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|
Integer |
Creates a reference to a context-specific instance of the specified service. |
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PowerObject |
Returns a reference to the name of the parent object. |
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|
Object |
Returns the type of the object. |
