CODEWITHSUNDEEP
objective-cobjective-c-blocks
A.T
A.T

Reputation: 115

completion block with parameters

I have written a method with completion block in nsobject class and call this method from uiviewcontroller, its working perfectly but how do I pass a nsstring parameter in this method ,following is my pice of code.

-(void)testingFunction:(void(^)(NSMutableArray* result))handler{
    NSMutableArray *dataArray = [[NSMutableArray alloc] init];
    NSMutableURLRequest* request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:urlstring]];
    NSString *authStr = @"";
    NSData *authData = [authStr dataUsingEncoding:NSUTF8StringEncoding];
    NSString *authValue = [NSString stringWithFormat: @"Basic %@",[authData base64EncodedStringWithOptions:0]];
    [request setValue:authValue forHTTPHeaderField:@"Authorization"];

    //create the task
    NSURLSessionDataTask* task = [[NSURLSession sharedSession] dataTaskWithRequest:request completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
    NSDictionary *json = [NSJSONSerialization JSONObjectWithData:data options:0 error:nil];
    [dataArray addObject:[[json objectForKey:@"query"] objectForKey:@"geosearch"]];
    dispatch_async(dispatch_get_main_queue(), ^{
        handler(dataArray) ;
      });
    }];
    [task resume];
}

and call this method from my uiviewcontroller 

[[AllFunction sharedInstance] testingFunction:^(NSMutableArray* testResult){
    [somearray addObject:testResult];
    NSLog(@"Result was %@", somearray);
    [self.tableView reloadData];
}];

Upvotes: 4

Views: 2533

Answers (2)

Moumou
Moumou

Reputation: 1532

If you want to pass a NSString* to the method:

-(void)testingFunction:(void(^)(NSMutableArray* result))handler andString:(NSString*) yourString;

Or if you want to pass a NSString* to the completion block:

-(void)testingFunction:(void(^)(NSMutableArray* result, NSString* yourString))handler;

Edit:

You can call the method like this:

NSString* yourString = @"Some Text";
testingFunction:^(NSMutableArray* result) {
    //Do whatever you want here
} andString:yourString;

Go read this: http://www.tutorialspoint.com/objective_c/objective_c_functions.htm

EDIT2:

As trojanfoe said, if your string is supposed to be an url you should use NSURL instead of NSString

Upvotes: 6

trojanfoe
trojanfoe

Reputation: 122468

As this "string" is really a URL, pass an NSURL instance instead:

-(void)testingFunction:(void(^)(NSMutableArray* result))handler
               withURL:(NSURL *)url
{
    NSMutableArray *dataArray = [[NSMutableArray alloc] init];
    NSMutableURLRequest* request = [NSMutableURLRequest requestWithURL:url];
    ....
}

However I am unsure why your question is entitled "completion block with parameters" as this question relates to an ordinary method.

Upvotes: 0

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