How to download CSV file from server in Objective-C

Question

I\'m developing a new iPhone application, Here i have parsed a \'csv\' file from local, and its working with me. When i try to download the \'csv\' file from the server prog

Answer 1

Implement this method:

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

You'll find that you're getting an error of

Error Domain=NSURLErrorDomain Code=-1000 "bad URL" UserInfo=0xf663f40 {NSUnderlyingError=0xf663de0 "bad URL", NSLocalizedDescription=bad URL}

I've looked into downloading information this way before, and I think one problem you're having is that separate symbols have to be separated with a "+". Also, when pulling an index, you can't pass the "^" symbol as part of the URL. You have to replace it with "%5E".

So, add this:

- (void) connection:(NSURLConnection *)connection didFailWithError:(NSError *)error {
    NSLog(@"%@", [error description]);
}

And change your URL to this:

NSString *urlString = @"http://download.finance.yahoo.com/d/quotes.csv?s=^GSPC+^IXIC+^dji+^GSPC+^BVSP+^GSPTSE+^FTSE+^GDAXI+^FCHI+^STOXX50E+^AEX+^IBEX+^SSMI+^N225+^AXJO+^HSI+^NSEI&f=sl1d1t1c1ohgv&e=.csv";
NSURL *url = [NSURL URLWithString:[urlString stringByAddingPercentEscapesUsingEncoding:NSASCIIStringEncoding]];

Now it works for me! I even checked the output .csv file, and it looks good to go! One full quote per line.

Answer 2

If you plan on fetching more data over the network than this single csv, you could have a look at AFNetworking, it's a great library for doing network operations.

A working solution would then look a bit like this:

- (void)getCSVAsynch {
    NSString *unescaped = @"http://download.finance.yahoo.com/d/quotes.csv?s=^GSPC,^IXIC,^dji,^GSPC,^BVSP,^GSPTSE,^FTSE,^GDAXI,^FCHI,^STOXX50E,^AEX,^IBEX,^SSMI,^N225,^AXJO,^HSI,^NSEI&f=sl1d1t1c1ohgv&e=.csv";
    NSURL *url = [NSURL URLWithString:[unescaped stringByAddingPercentEscapesUsingEncoding:NSASCIIStringEncoding]];
    NSURLRequest *request = [NSURLRequest requestWithURL:url];
    AFHTTPRequestOperation *operation = [[AFHTTPRequestOperation alloc] initWithRequest:request];
    [operation setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation, id responseObject) {
        NSLog(@"CSV: %@", [[NSString alloc] initWithBytes:[responseObject bytes] length:[responseObject length] encoding:NSUTF8StringEncoding]);
    } failure:^(AFHTTPRequestOperation *operation, NSError *error) {
        NSLog(@"Things go boom. %@", [error localizedDescription]);
    }];
    [operation start];
}