iOS HTTP Request called twice

Question

I have a function which makes GET request to the server. It works fine but for some reason it's called twice. I call function when a button is pressed.

This is function code:

-(void) GETasync: (NSString *) path{
    receivedData = [[NSMutableData alloc] init];
    NSURLRequest *request=[NSURLRequest requestWithURL:
                              [NSURL URLWithString: path]
                              cachePolicy:NSURLRequestReloadIgnoringLocalCacheData
                              timeoutInterval:60.0];
    NSHTTPURLResponse * response;
    NSError * error;
    NSData * data = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];  
    NSLog(@"data received");
}

So I see in output:

2012-03-07 16:36:41.509 KW2[24136:bf03] data received
2012-03-07 16:36:41.694 KW2[24136:bf03] data received

I also have a function for POST request and it's the same trouble with it.

Can you please show the code where you make the call to this method? — Markus Persson, Mar 07 '12 at 11:55
The problem has nothing to do with the connection POST. You button event is being called morethan once. How are you assinging the events on your button? — Felipe Sabino, Mar 07 '12 at 11:57
I'm having this same exact issue. I haven't figured out why, but I do think it will end up being related to something else calling your method (and mine) twice. — Bill Burgess, Mar 07 '12 at 13:51

score 0 · Answer 1 · answered Mar 07 '12 at 12:05

I am assuming that you are printing out that log within your delegate method connection:didReceiveData:. That method can be called multiple times for one single connection - in fact it is commonly called at least twice.

From the documentation:

The delegate is periodically sent connection:didReceiveData: messages as the data is received. The delegate implementation is responsible for storing the newly received data.

- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
    // Append the new data to receivedData.
    // receivedData is an instance variable declared elsewhere.
    [receivedData appendData:data];
}

EDIT: I see that in your latest edits you have added that logging information (or maybe I did not see it right away - shame on me).

Are you possibly calling that method by a notification handler? If so, have you possibly double-registered for that notification -> hence your handler is invoked twice.

score 0 · Accepted Answer · answered Mar 07 '12 at 14:35

0

The problem was just in that I wired IBOutlets from File'Owner and First Responder to buttons in IB.

After removing wires from File's Owner, the method started to be called only one time.

answered Mar 07 '12 at 14:35

Ilya Blokh

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score 0 · Answer 3 · answered Mar 07 '12 at 14:37

Also make sure to check the IBAction connections for your button in Interface Builder. If you copy and paste buttons in IB, you can end up having 2 or more identical IBAction connections for a button, which would cause the method to be executed twice with just one button click.

iOS HTTP Request called twice

3 Answers3