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NigelCollins

macrumors newbie
Original poster
Jan 25, 2013
1
0
I have a problem which I could really do with some help with please

I am using NSURLconnection to download a large file (27MB). the code work fine when there is no network interruption. In order to allow for network issues and only partially downloaded file I have added code to check to see how much of the file is downloaded and then using a server request to download the missing portion.

The code works as it should IF I download part of file, stop the program running and then run again - the download then commences where it left off and i have complete file.

However if I hit the download button a second time without stopping the program then didReceiveData only gets called once and adds just 200KB to the file and it tells me file has been succesfully downloaded.

Help please - I have spent ages trying to figure out what I'm doing wrong.

Code below:

Code:
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{

    NSHTTPURLResponse *httpResponse = (NSHTTPURLResponse*)response;

    NSLog(@"Response code = %d",httpResponse.statusCode );
     file = [NSFileHandle fileHandleForUpdatingAtPath:filename] ;// file is in .h


    if (file)   {
       [file seekToEndOfFile];
    }

}




- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{

    if (file)  {

        [file seekToEndOfFile];
        NSLog(@"file is %@",file);

    }

    [self.file writeData:data];
 }




- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{

    if([[NSFileManager defaultManager] fileExistsAtPath:filename])
    {
       [file closeFile];
        file = nil;
        theConnection = nil;
        filename = nil;
        theRequest = nil;
     }
     NSLog(@"Connection failed! Error - %@ %@",
     [error localizedDescription],
     [[error userInfo] objectForKey:NSURLErrorFailingURLStringErrorKey]);
}


- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{

    [file closeFile];
    file = nil;
    theConnection = nil;
    filename = nil;

}


- (IBAction)downloadFile:(id)sender {


    filename = [[NSSearchPathForDirectoriesInDomains(NSLibraryDirectory, NSUserDomainMask, YES) objectAtIndex:0] stringByAppendingPathComponent:movie1]; // filename is in .h file

    theRequest=[NSMutableURLRequest requestWithURL:[NSURL URLWithString:movieDownload1]                                          cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:60.0];

    NSUInteger downloadedBytes = 0;
    NSFileManager *fm = [NSFileManager defaultManager];
    if ([fm fileExistsAtPath:filename]) {
        NSError *error = nil;
        NSDictionary *fileDictionary = [fm attributesOfItemAtPath:filename error:&error];
        if (!error && fileDictionary)
        downloadedBytes = [fileDictionary fileSize];
    } else {
        [fm createFileAtPath:filename contents:nil attributes:nil];
    }

    if (downloadedBytes > 0) {
         NSString *requestRange = [NSString stringWithFormat:@"bytes=%d-",downloadedBytes];
        [theRequest setValue:requestRange forHTTPHeaderField:@"Range"];
    }

    theConnection = nil;
    theConnection = [NSURLConnection connectionWithRequest:theRequest delegate:self];

   }
 
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