Type Alias


The callback invoked when getting a property’s value.


typealias JSObjectGetPropertyCallback = (JSContextRef?, JSObjectRef?, JSStringRef?, UnsafeMutablePointer<JSValueRef?>?) -> JSValueRef?



The execution context to use.


The JSObject to search for the property.


A JSString containing the name of the property to get.


A pointer to a JSValueRef in which to return an exception, if any.

Return Value

The property's value if the object has the property, otherwise NULL.


If you named your function GetProperty, you would declare it like this:

JSValueRef GetProperty(JSContextRef ctx, JSObjectRef object, JSStringRef propertyName, JSValueRef* exception);

If this function returns NULL, the get request forwards to object’s statically declared properties, then its parent class chain (which includes the default object class), then its prototype chain.

See Also


typealias JSObjectCallAsConstructorCallback

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

typealias JSObjectCallAsFunctionCallback

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

typealias JSObjectConvertToTypeCallback

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

typealias JSObjectDeletePropertyCallback

The callback invoked when deleting a property.

typealias JSObjectFinalizeCallback

The callback invoked when an object is finalized (prepared for garbage collection). An object may be finalized on any thread.

typealias JSObjectGetPropertyNamesCallback

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

typealias JSObjectHasInstanceCallback

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

typealias JSObjectHasPropertyCallback

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

typealias JSObjectInitializeCallback

The callback invoked when an object is first created.

typealias JSObjectSetPropertyCallback

The callback invoked when setting a property’s value.