Structure

JSClassDefinition

This structure contains properties and callbacks that define a type of object. All fields other than the version field are optional. Any pointer may be NULL.

Declaration

typedef struct {
    ...
} JSClassDefinition;

Overview

The staticValues and staticFunctions arrays are the simplest and most efficient means for vending custom properties. Statically declared properties autmatically service requests like getProperty, setProperty, and getPropertyNames. Property access callbacks are required only to implement unusual properties, like array indexes, whose names are not known at compile-time.

If you named your getter function "GetX" and your setter function "SetX", you would declare a JSStaticValue array containing "X" like this:

JSStaticValue StaticValueArray[] = { { "X", GetX, SetX, kJSPropertyAttributeNone }, { 0, 0, 0, 0 } };

Standard JavaScript practice calls for storing function objects in prototypes, so they can be shared. The default JSClass created by JSClassCreate follows this idiom, instantiating objects with a shared, automatically generating prototype containing the class's function objects. The kJSClassAttributeNoAutomaticPrototype attribute specifies that a JSClass should not automatically generate such a prototype. The resulting JSClass instantiates objects with the default object prototype, and gives each instance object its own copy of the class's function objects.

A NULL callback specifies that the default object callback should substitute, except in the case of hasProperty, where it specifies that getProperty should substitute.