Convenience function to create a new object exactly as a constructor function would.
Syntax
JSObject * JS_NewObjectForConstructor(JSContext *cx, const JSClass *clasp, const JS::CallArgs& args); // Added in JSAPI 32 JSObject * JS_NewObjectForConstructor(JSContext *cx, JSClass *clasp, const jsval *vp); // Added in JSAPI 14, Obsolete since JSAPI 32 JSObject * JS_NewObjectForConstructor(JSContext *cx, const jsval *vp); // Obsolete since JSAPI 14
Name | Type | Description |
---|---|---|
cx |
JSContext * |
The context in which to create the new object. Requires request. In a JS_THREADSAFE build, the caller must be in a request on this JSContext . |
clasp |
const JSClass * |
The class of the object to create. Added in SpiderMonkey 17 |
vp |
jsval * |
Pointer to a constructor. This must be an object that has a prototype property. |
args |
JS::CallArgs & |
Call argument to get a constructor as callee . Added in SpiderMonkey 38 |
Description
JS_NewObjectForConstructor
creates a new object exactly as the given constructor would if invoked with new
. This function does not run the code of the constructor function--it just creates the object.
If the constructor argument is not an object jsval
, this function will assert (in debug builds). If the constructor does not have a prototype
property, this function will return NULL
and set an exception on cx
.
The standard object creation API, JS_NewObject
, takes explicit arguments for the class, prototype, and parent of the new object. With JS_NewObjectForConstructor
, the prototype and parent are determined by the constructor, and class is still determined by the caller. The prototype is the prototype of the constructor if it is an object, otherwise NULL
. The parent is the constructor's parent.
See Also
- MXR ID Search for
JS_NewObjectForConstructor
JS_NewObject
OBJECT_TO_JSVAL
- bug 581263 - added
- bug 738075 - added
clasp
parameter - bug 959787 - added
args
parameter