NSURLConnection connectionDidFinishLoading called before all file is downloaded

Question

I am using NSURLConnection to download a zipped file from a web service. In the didReceiveData I append the data to a file and using a good internet connection all appears to work correctly. The file is transparently unzipped as it is downloaded. If, however, I have a poor internet connection the connectionDidFinishLoading appears to be called before all the data has been received. Is there another delegate method that I should be trapping or some kind of timeout in NSURLConnection that is making it think that the download is finished as opposed to calling didFailWithError?

Answer 1

you should check that the size of the received data is as expected.

the following will get you the expected size of data:

-(void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response{
 long long dataSize = [response expectedContentLength];
}

every time you get a call to didReceiveData, reduce it from the dataSize, and if you get a call to connectionDidFinishLoading and the dataSize is bigger than 0, there is a problem.