EXTEND CLASS statement

The EXTEND CLASS statement extends an existing class.

Syntax

EXTEND CLASS name 
[{
    objectName1 [objectCaption1] [imageSetting1],
    ...
    objectNameM [objectCaptionM] [imageSettingM]
}] 
[: parent1, ..., parentN];

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. Name values are stored in the System.staticName system property.

• 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. Caption values are stored in the System.staticCaption system property.

• imageSetting1, ..., imageSettingM

  Settings for displaying icons in the captions of new static objects of this class. By default, the presence or absence of an icon is controlled by the parameters settings.defaultImagePathRankingThreshold and settings.defaultAutoImageRankingThreshold. The HTML class value used for displaying the icon is stored in the system property System.image[StaticObject]. This option allows you to manually configure the icon display. It can have one of two forms:

  • IMAGE [fileExpr]

    Specifying the relative path to the image file that will be displayed as the icon in the caption of the static object. If fileExpr is not specified, the default icon display mode is activated.

    • fileExpr

      Expression whose value specifies the path to the image file. The path is specified relative to the images directory.

  • NOIMAGE

    Keyword indicating that the static object's caption should have 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'
}