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    JS_NewObjectForConstructor

    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

    Document Tags and Contributors

    Contributors to this page: Sheppy, tschneidereit, Dmandelin, Waldo, arai
    Last updated by: arai,
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