Struct JSClassDefinition

#[repr(C)]
pub struct JSClassDefinition {

    pub version: c_int,
    pub attributes: JSClassAttributes,
    pub className: *const c_char,
    pub parentClass: JSClassRef,
    pub staticValues: *const JSStaticValue,
    pub staticFunctions: *const JSStaticFunction,
    pub initialize: JSObjectInitializeCallback,
    pub finalize: JSObjectFinalizeCallback,
    pub hasProperty: JSObjectHasPropertyCallback,
    pub getProperty: JSObjectGetPropertyCallback,
    pub setProperty: JSObjectSetPropertyCallback,
    pub deleteProperty: JSObjectDeletePropertyCallback,
    pub getPropertyNames: JSObjectGetPropertyNamesCallback,
    pub callAsFunction: JSObjectCallAsFunctionCallback,
    pub callAsConstructor: JSObjectCallAsConstructorCallback,
    pub hasInstance: JSObjectHasInstanceCallback,
    pub convertToType: JSObjectConvertToTypeCallback,
}

Contains properties and callbacks that define a type of object.

All fields other than the version field are optional. Any pointer may be NULL.

The staticValues and staticFunctions arrays are the simplest and most efficient means for vending custom properties. Statically declared properties automatically 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 JSClassRef 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 JSClassRef should not automatically generate such a prototype. The resulting JSClassRef 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.

Fields

version: c_int

The version number of this structure. The current version is 0.

attributes: JSClassAttributes

A logically ORed set of JSClassAttributes to give to the class.

className: *const c_char

A null-terminated UTF8 string containing the class’s name.

parentClass: JSClassRef

A JSClassRef to set as the class’s parent class. Pass NULL use the default object class.

staticValues: *const JSStaticValue

A JSStaticValue array containing the class’s statically declared value properties. Pass NULL to specify no statically declared value properties. The array must be terminated by a JSStaticValue whose name field is NULL.

staticFunctions: *const JSStaticFunction

A JSStaticFunction array containing the class’s statically declared function properties. Pass NULL to specify no statically declared function properties. The array must be terminated by a JSStaticFunction whose name field is NULL.

initialize: JSObjectInitializeCallback

The callback invoked when an object is first created. Use this callback to initialize the object.

finalize: JSObjectFinalizeCallback

The callback invoked when an object is finalized (prepared for garbage collection). Use this callback to release resources allocated for the object, and perform other cleanup.

hasProperty: JSObjectHasPropertyCallback

The callback invoked when determining whether an object has a property.

If this field is NULL, getProperty is called instead. The hasProperty callback enables optimization in cases where only a property’s existence needs to be known, not its value, and computing its value is expensive.

getProperty: JSObjectGetPropertyCallback

The callback invoked when getting a property’s value.

setProperty: JSObjectSetPropertyCallback

The callback invoked when setting a property’s value.

deleteProperty: JSObjectDeletePropertyCallback

The callback invoked when deleting a property.

getPropertyNames: JSObjectGetPropertyNamesCallback

The callback invoked when collecting the names of an object’s properties.

callAsFunction: JSObjectCallAsFunctionCallback

The callback invoked when an object is called as a function.

callAsConstructor: JSObjectCallAsConstructorCallback

The callback invoked when an object is used as a constructor in a new expression.

hasInstance: JSObjectHasInstanceCallback

The callback invoked when an object is used as the target of an instanceof expression.

convertToType: JSObjectConvertToTypeCallback

The callback invoked when converting an object to a particular JavaScript type.

Trait Implementations

impl Clone for JSClassDefinition

fn clone(&self) -> JSClassDefinition

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for JSClassDefinition

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for JSClassDefinition

fn default() -> Self

Returns the “default value” for a type.

impl Copy for JSClassDefinition