Better control around cancellation

Author: wibosco

NetworkingWingman-Example/Managers/Queue/NWMOperationQueueManager.m

@@ -24,13 +24,13 @@ @implementation NWMOperationQueueManager
 + (instancetype)sharedInstance
 {
     static NWMOperationQueueManager *sharedInstance = nil;
-    
+
     static dispatch_once_t onceToken;
     dispatch_once(&onceToken, ^
                   {
                       sharedInstance = [[NWMOperationQueueManager alloc] init];
                   });
-    
+
     return sharedInstance;
 }
 
@@ -39,12 +39,12 @@ + (instancetype)sharedInstance
 - (instancetype)init
 {
     self = [super init];
-    
+
     if (self)
     {
         self.queue = [[NSOperationQueue alloc] init];
     }
-    
+
     return self;
 }
 

NetworkingWingman-Example/Networking/Abstract/Operation/NWMOperation.m

@@ -10,9 +10,6 @@
 
 @implementation NWMOperation
 
-/*
- We need to do old school synthesizing as the compiler has trouble creating the internal ivars.
- */
 @synthesize ready = _ready;
 @synthesize executing = _executing;
 @synthesize finished = _finished;
@@ -22,12 +19,12 @@ @implementation NWMOperation
 - (instancetype)init
 {
     self = [super init];
-    
+
     if (self)
     {
         self.ready = YES;
     }
-    
+
     return self;
 }
 
@@ -45,7 +42,7 @@ - (void)setReady:(BOOL)ready
 
 - (BOOL)isReady
 {
-    return _ready;
+    return [super isReady] && _ready;
 }
 
 - (void)setExecuting:(BOOL)executing
@@ -78,34 +75,49 @@ - (BOOL)isFinished
     return _finished;
 }
 
-- (BOOL)isAsynchronous
-{
-    return YES;
-}
-
-#pragma mark - Control
+#pragma mark - Start
 
 - (void)start
 {
+    if (self.isCancelled)
+    {
+        [self finish];
+        return;
+    }
+
     if (!self.isExecuting)
     {
         self.ready = NO;
         self.executing = YES;
         self.finished = NO;
-        
-        NSLog(@"\"%@\" Operation Started.", self.name);
     }
 }
 
+#pragma mark - Finish
+
 - (void)finish
 {
     if (self.executing)
     {
-        NSLog(@"\"%@\" Operation Finished.", self.name);
-        
         self.executing = NO;
         self.finished = YES;
     }
 }
 
+#pragma mark - Cancel
+
+- (void)cancel
+{
+    [super cancel];
+
+    [self finish];
+}
+
+#pragma mark - Asynchronous
+
+- (BOOL)isAsynchronous
+{
+    return YES;
+}
+
 @end

NetworkingWingman-Example/Networking/Answers/NWMAnswersAPIManager.m

@@ -18,7 +18,7 @@ @implementation NWMAnswersAPIManager
 + (void)retrieveAnswersWithCompletion:(void (^)(NSArray *answers))completion
 {
     NWMAnswersRetrievalOperation *operation = [[NWMAnswersRetrievalOperation alloc] initWithCompletion:completion];
-    
+
     [[NWMOperationQueueManager sharedInstance] addOperation:operation];
 }
 

NetworkingWingman-Example/Networking/Answers/Operations/Retrieval/NWMAnswersRetrievalOperation.m

@@ -7,6 +7,7 @@
 //
 
 #import "NWMAnswersRetrievalOperation.h"
+
 #import "NWMAnswerParser.h"
 
 @interface NWMAnswersRetrievalOperation ()
@@ -25,13 +26,13 @@ @implementation NWMAnswersRetrievalOperation
 - (instancetype)initWithCompletion:(void (^)(NSArray *answers))completion
 {
     self = [super init];
-    
+
     if (self)
     {
         self.completion = completion;
         self.name = @"Answers-Retrieval";
     }
-    
+
     return self;
 }
 
@@ -40,38 +41,30 @@ - (instancetype)initWithCompletion:(void (^)(NSArray *answers))completion
 - (void)start
 {
     [super start];
-    
+
     NSURLSession *session = [NSURLSession sharedSession];
-    
+
     NSURL *url = [NSURL URLWithString:@"https://api.stackexchange.com/2.2/answers?site=stackoverflow"];
-    
+
     NSURLSessionDataTask *task = [session dataTaskWithURL:url
                                         completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error)
                                   {
                                       NSDictionary *answersJSON = [NSJSONSerialization JSONObjectWithData:data
                                                                                                   options:NSJSONReadingMutableContainers
                                                                                                     error:nil];
-                                      
+
                                       NWMAnswerParser *parser = [[NWMAnswerParser alloc] init];
                                       NSArray *answers = [parser parseAnswers:answersJSON[@"items"]];
-                                      
+
                                       if (self.completion)
                                       {
                                           self.completion(answers);
                                       }
-                                      
+
                                       [self finish];
                                   }];
-    
+
     [task resume];
 }
 
-#pragma mark - Cancel
-
-- (void)cancel
-{
-    [super cancel];
-    
-    [self finish];
-}
 @end

README.md

@@ -1,5 +1,5 @@
 [![Build](https://github.com/wibosco/NetworkingWingman-Example/actions/workflows/objective-c-xcode.yml/badge.svg)](https://github.com/wibosco/NetworkingWingman-Example/actions/workflows/objective-c-xcode.yml)
-<a href="https://developer.apple.com/library/archive/documentation/Cocoa/Conceptual/ProgrammingWithObjectiveC/Introduction/Introduction.html#//apple_ref/doc/uid/TP40011210"><img src="https://img.shields.io/badge/Objective--c-language-blue" alt="Objective-C" /></a>
+<a href="https://developer.apple.com/library/archive/documentation/Cocoa/Conceptual/ProgrammingWithObjectiveC/Introduction/Introduction.html#//apple_ref/doc/uid/TP40011210"><img src="https://img.shields.io/badge/Objective--C-2.0-blue" alt="Objective-C" /></a>
 [![License](http://img.shields.io/badge/License-MIT-green.svg?style=flat)](https://github.com/wibosco/NetworkingWingman-Example/blob/main/LICENSE)
 
 # NetworkingWingman-Example