CODEWITHSUNDEEP
iosiphonensurlcache
Ja5onHoffman
Ja5onHoffman

Reputation: 672

Simple NSURLCache Implementation on iOS8

I'm having trouble getting a simple implementation of NSURLCache working on iOS8. It's my understanding that once a shared cache is created, it automatically caches data requests with the proper cache policy. No configuration required unless you want to customize behavior. Is this correct?

I've included a simplified version of my code below. The cache is created in AppDelegate, and the TableViewController that needs the data uses the APICaller object to make the call. The request is using NSURLRequestReturnCacheDataElseLoad, as this information doesn't need to be updated frequently.

If I'm way off the mark here. What's the next step? The data received is 95KB.

AppDelegate:

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    // Override point for customization after application launch.

    NSURLCache *URLCache = [[NSURLCache alloc] initWithMemoryCapacity:4 * 1024 * 1024 diskCapacity:20 * 1024 * 1024 diskPath:nil];
    [NSURLCache setSharedURLCache:URLCache];


    return YES;
}

TableViewController:

- (void)viewDidLoad {

  APICaller *apiCaller = [APICaller alloc] init];
  [apiCaller makeAPICallWithCompletionHandler:^(NSArray *result, NSError *error){
    if (error) {

      // Handle error
    } else {
    self.property = [result mutableCopy];
    [self.tableView reloadData];

      }

    }

}

APICaller:

- (void)makeAPICallWithCompletionHandler:(void(^)(NSArray *result, NSError *error))completionHandler
{
    NSString *urlString = [NSString stringWithFormat@"https://api.apiwebsite.com/json/query?key=@", API_KEY];
    NSURL *url = [NSURL URLWithString:urlString];
    NSURLRequest *request = [NSURLRequest requestWithURL:url cachePolicy:NSURLRequestReturnCacheDataElseLoad timeoutInterval:10];
    NSURLSessionConfiguration *config = [NSURLSession defaultSessionConfiguration];
    self.urlSession = [URLSession sessionWithConfiguration:config delegate:self delegateQueue:nil];

    NSURLSessionDataTask *dataTask = [self.URLSession dataTaskWithRequest:request completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
    if (error) {
        NSLog(@"There was an error");
        dispatch_async(dispatch_get_main_queue(), ^{
            completionHandler(nil, error);
        });
    } else {

        NSDictionary *dict = [NSJSONSerialization JSONObjectWithData:data options:0 error:&error];
        NSSortDescriptor *sortByName = [NSSortDescriptor sortDescriptorWithKey:@"name" ascending:YES selector:@selector(caseInsensitiveCompare:)];
        NSArray *sortDescriptors = [NSArray arrayWithObject:sortByName];
        NSArray *sortedResult = [dict[@"result"] sortedArrayUsingDescriptors:sortDescriptors];

        dispatch_async(dispatch_get_main_queue(), ^{
            completionHandler(sortedResponse, error);
        });
      }

    }];

    [dataTask resume];
}

Upvotes: 0

Views: 158

Answers (1)

cschandler
cschandler

Reputation: 544

According to this post and this post NSURLCache is broken in iOS 8 when using NSURLSession.

According to the first post I linked, NSURLConnection still seems to work. I remember seeing in one of the comments that this was still the case as of early Feb, but I haven't had a chance to investigate myself.

Best of luck.

Upvotes: 1

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