This article covers features introduced in SpiderMonkey 38
Create a new Function object from an existing JSFunction.
Syntax
JSObject *
JS::CloneFunctionObject(JSContext *cx, JS::HandleObject funobj);
JSObject *
JS::CloneFunctionObject(JSContext *cx, JS::HandleObject funobj,
JS::AutoObjectVector &scopeChain);
| Name | Type | Description |
|---|---|---|
cx |
JSContext * |
Pointer to a JS context from which to derive runtime information. Requires request. In a JS_THREADSAFE build, the caller must be in a request on this JSContext. |
funobj |
JS::HandleObject |
The Function to clone. |
scopeChain |
JS::AutoObjectVector |
The new function's scope chain. |
Description
JS::CloneFunctionObject creates a new function object from funobj. The new object has the same code and argument list as funobj. If scopeChain is supplied, it uses scopeChain as its enclosing scope. If scopeChain is omitted, it creates a new function object in cx's global. This can be helpful if funobj is an extant function that you wish to use as if it were enclosed by a newly-created global object.
The new object's prototype is Function.prototype; JS_NewObject : Choosing a Default Prototype explains exactly how this is computed. JS::CloneFunctionObject takes care to choose a prototype that shares a global object with the given parent whenever possible.
funobj must be a pointer to a JavaScript function object (see JS_ObjectIsFunction).
On success, JS::CloneFunctionObject returns a pointer to the newly created object. If the class of funobj is not Function, then JS::CloneFunctionObjectfunobj itself. On failure, it returns NULL.