|  | /* | 
|  | * | 
|  | * Copyright 2015 gRPC authors. | 
|  | * | 
|  | * Licensed under the Apache License, Version 2.0 (the "License"); | 
|  | * you may not use this file except in compliance with the License. | 
|  | * You may obtain a copy of the License at | 
|  | * | 
|  | *     http://www.apache.org/licenses/LICENSE-2.0 | 
|  | * | 
|  | * Unless required by applicable law or agreed to in writing, software | 
|  | * distributed under the License is distributed on an "AS IS" BASIS, | 
|  | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | 
|  | * See the License for the specific language governing permissions and | 
|  | * limitations under the License. | 
|  | * | 
|  | */ | 
|  |  | 
|  | #import "GRXMappingWriter.h" | 
|  |  | 
|  | @interface GRXForwardingWriter ()<GRXWriteable> | 
|  | @end | 
|  |  | 
|  | @implementation GRXMappingWriter { | 
|  | id (^_map)(id value); | 
|  | } | 
|  |  | 
|  | - (instancetype)initWithWriter:(GRXWriter *)writer { | 
|  | return [self initWithWriter:writer map:nil]; | 
|  | } | 
|  |  | 
|  | // Designated initializer | 
|  | - (instancetype)initWithWriter:(GRXWriter *)writer map:(id (^)(id value))map { | 
|  | if ((self = [super initWithWriter:writer])) { | 
|  | _map = map ?: ^id(id value) { | 
|  | return value; | 
|  | }; | 
|  | } | 
|  | return self; | 
|  | } | 
|  |  | 
|  | // Override | 
|  | - (void)writeValue:(id)value { | 
|  | [super writeValue:_map(value)]; | 
|  | } | 
|  | @end |