public static bool SetPrototypeOf(ObjectInstance target, object prototype)
{
// The prototype must be null or an object. Note that null in .NET is actually undefined in JS!
var prototypeObj = prototype as ObjectInstance;
if (prototypeObj == null && prototype != Null.Value)
{
throw new JavaScriptException(ErrorType.TypeError, "Object prototype may only be an Object or null.");
}
return(target.SetPrototype(prototypeObj));
}
public static ObjectInstance SetPrototypeOf(ObjectInstance obj, object prototype)
{
// The prototype must be null or an object. Note that null in .NET is actually undefined in JS!
var prototypeObj = prototype as ObjectInstance;
if (prototypeObj == null && prototype != Null.Value)
{
throw new JavaScriptException(ErrorType.TypeError, "Object prototype may only be an Object or null.");
}
// Attempt to set the prototype.
obj.SetPrototype(prototypeObj, throwOnError: true);
return(obj);
}
public static ObjectInstance SetPrototypeOf(ObjectInstance obj, object prototype)
{
// The prototype must be null or an object. Note that null in .NET is actually undefined in JS!
var prototypeObj = prototype as ObjectInstance;
if (prototypeObj == null && prototype != Null.Value)
{
throw new JavaScriptException(obj.Engine, ErrorType.TypeError, "Object prototype may only be an Object or null.");
}
// Attempt to set the prototype.
if (!obj.SetPrototype(prototypeObj))
{
// Attempt to throw a reasonable error message based on what we know about how SetPrototype works.
if (!obj.IsExtensible)
{
throw new JavaScriptException(obj.Engine, ErrorType.TypeError, "Object is not extensible.");
}
throw new JavaScriptException(obj.Engine, ErrorType.TypeError, "Prototype chain contains a cyclic reference.");
}
return(obj);
}
/// <summary>
/// Sets the next object in the prototype chain. Can be <c>null</c>, which indicates there
/// are no further objects in the chain.
/// </summary>
/// <param name="prototype"> The new prototype. </param>
/// <param name="throwOnError"> <c>true</c> to throw an exception if the prototype could not
/// be set. This can happen if the object is non-extensible or if setting the prototype
/// would introduce a cyclic dependency. </param>
/// <returns> <c>true</c> if the prototype was successfully applied; <c>false</c> otherwise. </returns>
internal override bool SetPrototype(ObjectInstance prototype, bool throwOnError)
{
// Check for revocation.
if (target == null || handler == null)
{
throw new JavaScriptException(ErrorType.TypeError, "Cannot call 'setPrototypeOf' on a proxy that has been revoked.");
}
// Call the handler, if one exists.
var trap = handler.GetMethod("setPrototypeOf");
if (trap == null)
{
return(target.SetPrototype(prototype, throwOnError));
}
var result = TypeConverter.ToBoolean(trap.CallLateBound(handler, target, prototype));
// Validate.
if (result == false)
{
if (throwOnError)
{
throw new JavaScriptException(ErrorType.TypeError, "'setPrototypeOf' on proxy: trap returned falsish.");
}
return(false);
}
if (target.IsExtensible)
{
return(true);
}
// Trap returned true, and target is non-extensible.
if (target.Prototype != prototype)
{
throw new JavaScriptException(ErrorType.TypeError, "'setPrototypeOf' on proxy: proxy target is non-extensible but the trap did not return its actual prototype.");
}
return(true);
}
