NSURLConnection return bad cacheData - ios

Question

In my AppDelegate method I create cache
NSURLCache *URLCache = [[NSURLCache alloc] initWithMemoryCapacity:(10 * 1024 * 1024) diskCapacity:(100 * 1024 * 1024) diskPath:nil];
[NSURLCache setSharedURLCache:URLCache];
I have next NSURLConnection class
#implementation ImageDownloader {
NSURLConnection *serverConnection;
NSMutableData *imageData;
}
- (void)startDownloading
{
NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:self.link] cachePolicy:NSURLRequestReturnCacheDataElseLoad timeoutInterval:10];
imageData = [NSMutableData new];
serverConnection = [[NSURLConnection alloc] initWithRequest:request delegate:self startImmediately:NO];
[serverConnection scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSRunLoopCommonModes];
[serverConnection start];
}
- (void)cancelDownloading
{
[serverConnection cancel];
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
[imageData appendData:data];
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
UIImage *image = [[UIImage alloc] initWithData:imageData];
[self sendDelegateImage:image];
}
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{
[self sendDelegateImage:nil];
}
- (void)sendDelegateImage:(UIImage *)image
{
[self.delegate imageDownloader:self didLoadAtIndexPath:self.indexPath image:image];
}
#end
I use it when my tableView cells appears. In first load all good, and in first use of cache all good, but when I load my tableView in third time, cache data returned very small, and I have not image. Why NSURLConnection return bad cached data?

Answer 1

You could try implementing connection:didReceiveResponse:
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
self.dataReceived = [[NSMutableData alloc] init];
}
From the docs:
In rare cases, for example in the case of an HTTP load where the
content type of the load data is multipart/x-mixed-replace, the
delegate will receive more than one connection:didReceiveResponse:
message. In the event this occurs, delegates should discard all data
previously delivered by connection:didReceiveData:, and should be
prepared to handle the, potentially different, MIME type reported by
the newly reported URL response.
Edit:
Also, just noticed you are using [NSMutableData new] to initialise your data; you should be using [NSMutableData alloc] init].