JS_SetProperty

Syntax

JSBool JS_SetProperty(JSContext *cx, JSObject *obj,
    const char *name, jsval *vp);

JSBool JS_SetUCProperty(JSContext *cx, JSObject *obj,
    const jschar *name, size_t namelen, jsval *vp);

Description

JS_SetProperty assigns the value *vp to the property name of the object obj. JS_SetUCProperty is the Unicode version of the function.

vp points to a variable containing the new value to assign to the property.

If obj does not already have a name property of its own, this function creates it, and inherits its attributes from a like-named property in the object's prototype chain. For properties it creates, JS_SetProperty sets the JSPROP_ENUMERATE attribute in the property's flags field. (This is unclear: is the new property enumerable even if the like-named prototype property was DontEnum?)

On success, JS_SetProperty returns JS_TRUE. Otherwise it returns JS_FALSE.

If you attempt to set the value for a read-only property using JavaScript 1.2 or earlier, JS_SetProperty reports an error and returns JS_FALSE. For JavaScript 1.3 and greater, such an attempt is silently ignored.

If you attempt to set the value for a property that does not exist, and there is a like-named read-only property in the object's prototype chain, JS_SetProperty creates a new read-only property on the object, sets its value to JSVAL_VOID, and reports a read-only violation error.

See Also

LXR ID Search for JS_SetProperty
LXR ID Search for JS_SetUCProperty

JS_DefineProperty, JS_DefinePropertyWithTinyId, JS_DeleteProperty, JS_DeleteProperty2, JS_GetProperty, JS_LookupProperty, JS_PropertyStub