|
public GetOwnPropertyDescriptor ( object key ) : |
||
| key | object | The property key (either a string or a Symbol). |
| return | ||
public static ObjectInstance DefineProperty([JSParameter(JSParameterFlags.DoNotConvert)] ObjectInstance obj, string propertyName, [JSParameter(JSParameterFlags.DoNotConvert)] ObjectInstance attributes)
{
var defaults = obj.GetOwnPropertyDescriptor(propertyName);
var descriptor = PropertyDescriptor.FromObject(attributes, defaults);
obj.DefineProperty(propertyName, descriptor, true);
return(obj);
}
public static ObjectInstance GetOwnPropertyDescriptor([JSParameter(JSParameterFlags.DoNotConvert)] ObjectInstance obj, string propertyName)
{
var descriptor = obj.GetOwnPropertyDescriptor(propertyName);
if (descriptor.Exists == false)
{
return(null);
}
return(descriptor.ToObject(obj.Engine));
}
public static ObjectInstance GetOwnPropertyDescriptor(ObjectInstance obj, object key)
{
var descriptor = obj.GetOwnPropertyDescriptor(TypeConverter.ToPropertyKey(key));
if (descriptor.Exists == false)
{
return(null);
}
return(descriptor.ToObject(obj.Engine));
}
public static bool DefineProperty(ObjectInstance target, object propertyKey, object attributes)
{
propertyKey = TypeConverter.ToPropertyKey(propertyKey);
var defaults = target.GetOwnPropertyDescriptor(propertyKey);
if (!(attributes is ObjectInstance))
{
throw new JavaScriptException(ErrorType.TypeError, $"Invalid property descriptor '{attributes}'.");
}
var descriptor = PropertyDescriptor.FromObject((ObjectInstance)attributes, defaults);
return(target.DefineProperty(propertyKey, descriptor, throwOnError: false));
}
public static ObjectInstance DefineProperty(ObjectInstance obj, object key, object attributes)
{
key = TypeConverter.ToPropertyKey(key);
var defaults = obj.GetOwnPropertyDescriptor(key);
if (!(attributes is ObjectInstance))
{
throw new JavaScriptException(obj.Engine, ErrorType.TypeError, "Invalid descriptor for property '{propertyName}'.");
}
var descriptor = PropertyDescriptor.FromObject((ObjectInstance)attributes, defaults);
obj.DefineProperty(key, descriptor, true);
return(obj);
}
public static ArrayInstance Keys(ObjectInstance obj)
{
var result = obj.Engine.Array.New();
foreach (var key in obj.OwnKeys)
{
if (key is string)
{
var propertyDescriptor = obj.GetOwnPropertyDescriptor(key);
if (propertyDescriptor.Exists && propertyDescriptor.IsEnumerable)
{
result.Push(key);
}
}
}
return(result);
}
public static ObjectInstance DefineProperties(object obj, ObjectInstance properties)
{
if (obj is ObjectInstance objectInstance)
{
foreach (var key in properties.OwnKeys)
{
var descriptor = properties.GetOwnPropertyDescriptor(key);
if (descriptor.IsEnumerable)
{
// Spec says call [[Get]] instead of just using the value from the descriptor.
DefineProperty(objectInstance, key, properties[key]);
}
}
return(objectInstance);
}
throw new JavaScriptException(ErrorType.TypeError, "Object.defineProperties called on non-object.");
}
/// <summary>
/// Gets a descriptor for the property with the given name.
/// </summary>
/// <param name="key"> The property key (either a string or a Symbol). </param>
/// <returns> A property descriptor containing the property value and attributes. </returns>
/// <remarks>
/// Enforces the following invariants:
/// * The result of [[GetOwnProperty]] must be either an Object or undefined.
/// * A property cannot be reported as non-existent, if it exists as a non-configurable own
/// property of the target object.
/// * A property cannot be reported as non-existent, if the target object is not
/// extensible, unless it does not exist as an own property of the target object.
/// * A property cannot be reported as existent, if the target object is not extensible,
/// unless it exists as an own property of the target object.
/// * A property cannot be reported as non-configurable, unless it exists as a
/// non-configurable own property of the target object.
/// * A property cannot be reported as both non-configurable and non-writable, unless it
/// exists as a non-configurable, non-writable own property of the target object.
/// </remarks>
public override PropertyDescriptor GetOwnPropertyDescriptor(object key)
{
// Check for revocation.
if (target == null || handler == null)
{
throw new JavaScriptException(ErrorType.TypeError, "Cannot call 'getOwnPropertyDescriptor' on a proxy that has been revoked.");
}
// Call the handler, if one exists.
var trap = handler.GetMethod("getOwnPropertyDescriptor");
if (trap == null)
{
return(target.GetOwnPropertyDescriptor(key));
}
var result = trap.CallLateBound(handler, target, key);
// Validate.
var targetDescriptor = target.GetOwnPropertyDescriptor(key);
if (result is ObjectInstance propertyDescriptorObject)
{
var propertyDescriptor = PropertyDescriptor.FromObject(propertyDescriptorObject, PropertyDescriptor.Undefined);
if (!IsCompatiblePropertyDescriptor(target.IsExtensible, propertyDescriptor, targetDescriptor))
{
throw new JavaScriptException(ErrorType.TypeError, $"'getOwnPropertyDescriptor' on proxy: trap returned descriptor for property '{TypeConverter.ToString(key)}' that is incompatible with the existing property in the proxy target.");
}
if (!propertyDescriptor.IsConfigurable)
{
if (!targetDescriptor.Exists || targetDescriptor.IsConfigurable)
{
throw new JavaScriptException(ErrorType.TypeError, $"'getOwnPropertyDescriptor' on proxy: trap reported non-configurability for property '{TypeConverter.ToString(key)}' which is either non-existent or configurable in the proxy target.");
}
if (!propertyDescriptor.IsWritable && targetDescriptor.IsWritable)
{
throw new JavaScriptException(ErrorType.TypeError, $"'getOwnPropertyDescriptor' on proxy: trap reported non-configurable and writable for property '{TypeConverter.ToString(key)}' which is non-configurable, non-writable in the proxy target.");
}
}
return(propertyDescriptor);
}
else if (result == null || result == Undefined.Value)
{
if (!targetDescriptor.Exists)
{
return(PropertyDescriptor.Missing);
}
if (!targetDescriptor.IsConfigurable)
{
throw new JavaScriptException(ErrorType.TypeError, $"'getOwnPropertyDescriptor' on proxy: trap returned undefined for property '{TypeConverter.ToString(key)}' which is non-configurable in the proxy target.");
}
if (!target.IsExtensible)
{
throw new JavaScriptException(ErrorType.TypeError, $"'getOwnPropertyDescriptor' on proxy: trap returned undefined for property '{TypeConverter.ToString(key)}' which exists in the non-extensible proxy target.");
}
return(PropertyDescriptor.Missing);
}
else
{
throw new JavaScriptException(ErrorType.TypeError, $"'getOwnPropertyDescriptor' on proxy: trap returned neither object nor undefined for property '{TypeConverter.ToString(key)}'.");
}
}
public static ObjectInstance GetOwnPropertyDescriptor(ObjectInstance obj, object key)
{
var descriptor = obj.GetOwnPropertyDescriptor(TypeConverter.ToPropertyKey(key));
if (descriptor.Exists == false)
return null;
return descriptor.ToObject(obj.Engine);
}
public static ObjectInstance DefineProperty(ObjectInstance obj, object key, object attributes)
{
key = TypeConverter.ToPropertyKey(key);
var defaults = obj.GetOwnPropertyDescriptor(key);
if (!(attributes is ObjectInstance))
throw new JavaScriptException(obj.Engine, ErrorType.TypeError, "Invalid descriptor for property '{propertyName}'.");
var descriptor = PropertyDescriptor.FromObject((ObjectInstance)attributes, defaults);
obj.DefineProperty(key, descriptor, true);
return obj;
}
/// <summary>
/// Sets the value of a object literal property to a setter. If the value already has a
/// getter then it will be retained.
/// </summary>
/// <param name="obj"> The object to set the property on. </param>
/// <param name="key"> The property key (can be a string or a symbol).</param>
/// <param name="setter"> The setter function. </param>
public static void SetObjectLiteralSetter(ObjectInstance obj, object key, UserDefinedFunction setter)
{
var descriptor = obj.GetOwnPropertyDescriptor(key);
if (descriptor.Exists == false || !descriptor.IsAccessor)
obj.DefineProperty(key, new PropertyDescriptor(null, setter, Library.PropertyAttributes.FullAccess), throwOnError: false);
else
obj.DefineProperty(key, new PropertyDescriptor(descriptor.Getter, setter, Library.PropertyAttributes.FullAccess), throwOnError: false);
}
