Updating progress bar for a download-- NSURLConnectionDataDelegate didReceiveData gets only called once

Question

I am trying to download small PDF files 1-2Mb maybe 5 Mb at most. I am working on SelectionViewController.m class which has a UIProgressView called progressBar and it also implements the NSURLConnectionDataDelegate protocol.

The funny thing is that my progress bar goes from 0.0 to 1.0 suddenly. I would like to increment this slowly so it looks nice.

Here is my code:

    -(void)downloadPDFToMyDocumentsFrom:(NSString*) PDFUrl filename:(NSString *) title {

    NSURL *url = [[NSURL alloc] initWithString:PDFUrl];
    NSURLRequest *request = [[NSURLRequest alloc] initWithURL:url];

    urlConnection = [[NSURLConnection alloc] initWithRequest:request delegate:self startImmediately:YES];

    NSLog(@"%@", self);

    fileName = [title stringByAppendingPathExtension:@"pdf"];
    filePath = [[SearchFeed pathToDocuments] stringByAppendingPathComponent:fileName];

}



 //handling incoming data
 -(void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)recievedData{

     if(self.data == nil)
     {
        self.data = [[NSMutableData alloc] initWithCapacity:2048];
     }

     [self.data appendData:recievedData];

     NSNumber *resourceLength = [NSNumber numberWithUnsignedInteger:[self.data length]];

     float progress = [resourceLength floatValue] /[fileLength floatValue];
     self.progressBar.progress = progress;

}
-(void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response{
    long length = [response expectedContentLength];
    fileLength = [NSNumber numberWithUnsignedInteger:length];
    //lastProgress = 0.0;
    //currentLength = 0.0;
    NSLog(@"%f ------------------------------------------------------- is the fileLength", [fileLength floatValue]);
}

    //handling connection progress

-(void)connectionDidFinishLoading:(NSURLConnection *)connection{
    //WRITE code to set the progress bar to 1.0
    //self.progressBar.progress = 1.0;
    // [fileStream close];
    [self.data writeToFile:filePath atomically:YES];

    //[listFileAtPath:self.filePath];
    connection = nil;
    NSLog(@"%f %f-------------------------------------------- Finished Loading ", lastProgress, [fileLength floatValue]);
}

I have put some NSLog statements to help me debug and it seems like its downloading all at once.

Here is the output of all the NSLog:

2013-09-05 20:30:04.856 Revista[63246:c07] <SelectionViewController: 0x7180000>
2013-09-05 20:30:04.859 Revista[63246:c07] 63561.000000 ------------------------------------------------------- is the fileLength
2013-09-05 20:30:04.861 Revista[63246:c07] 0.000000 63561.000000-------------------------------------------- Finished Loading 

Do you guys have any idea on how to make it download in pieces and make the progress bar move smoothly?

Answer 1

Nevermind, my network is too fast! That's why I couldn't see the download in progress because it is lightening quick.

Thanks to Comcast!