EXTEND CLASS statement

The EXTEND CLASS statement extends an existing class.

Syntax

EXTEND CLASS name 
[{
    objectName1 [objectCaption1] [imageSetting],
    ...
    objectNameM [objectCaptionM] [imageSetting]
}] 
[: parent1, ..., parentN];

Where imageSetting is one of:

IMAGE [imageLiteral]
NOIMAGE

Description

The EXTEND CLASS statement extends an existing custom class with additional parent classes and new static objects. You can also extend abstract classes by adding parent classes to them.

Parameters

• name

  Class name. A composite ID.

• objectName1, ..., objectNameM

  Names of new static objects of the specified class. Each name is defined by a simple ID. The name[StaticObject] property returns this name qualified with the namespace and class — the object's canonical name.

• objectCaption1, ..., objectCaptionM

  Captions of new static objects of the specified class. Each caption is a string literal. If the caption is not defined, the name of the static object will be its caption. The caption of each static object is available through the caption[StaticObject] property.

• imageSetting

  Icon setting for a static object. One of:

  • IMAGE

    Manual icon specification, optionally followed by imageLiteral — a string literal whose value defines the icon. If imageLiteral is omitted, the automatic assignment mode is enabled.

  • NOIMAGE

    The static object has no icon.

• parent1, ..., parentN

  A list of names of new parent classes. Each name is defined by a composite ID.

Examples

CLASS ABSTRACT Shape;
CLASS Box : Shape;

CLASS Quadrilateral;
EXTEND CLASS Box : Quadrilateral; // Adding inheritance

CLASS ShapeType {
	point 'Dot',
	segment 'Line segment'
}

EXTEND CLASS ShapeType { // Adding a static object
	circle 'Circle'
}