1 /* 2 * 3 * Copyright 2015 gRPC authors. 4 * 5 * Licensed under the Apache License, Version 2.0 (the "License"); 6 * you may not use this file except in compliance with the License. 7 * You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 * 17 */ 18 19 #import <Foundation/Foundation.h> 20 21 /** 22 * A GRXWriteable is an object to which a sequence of values can be sent. The 23 * sequence finishes with an optional error. 24 */ 25 @protocol GRXWriteable<NSObject> 26 27 /** Push the next value of the sequence to the receiving object. */ 28 - (void)writeValue:(id)value; 29 30 /** 31 * Signal that the sequence is completed, or that an error ocurred. After this 32 * message is sent to the instance, neither it nor writeValue: may be 33 * called again. 34 */ 35 - (void)writesFinishedWithError:(NSError *)errorOrNil; 36 @end 37 38 typedef void (^GRXValueHandler)(id value); 39 typedef void (^GRXCompletionHandler)(NSError *errorOrNil); 40 typedef void (^GRXSingleHandler)(id value, NSError *errorOrNil); 41 typedef void (^GRXEventHandler)(BOOL done, id value, NSError *error); 42 43 /** 44 * Utility to create objects that conform to the GRXWriteable protocol, from 45 * blocks that handle each of the two methods of the protocol. 46 */ 47 @interface GRXWriteable : NSObject<GRXWriteable> 48 49 + (instancetype)writeableWithSingleHandler:(GRXSingleHandler)handler; 50 + (instancetype)writeableWithEventHandler:(GRXEventHandler)handler; 51 52 - (instancetype)initWithValueHandler:(GRXValueHandler)valueHandler 53 completionHandler:(GRXCompletionHandler)completionHandler 54 NS_DESIGNATED_INITIALIZER; 55 @end 56