get web page source in objective-c - ios

Question

i start developing in iOS and i have the next problem:
i need to extract the page source of web page to extract some data from it.
with some urls i'v succseed and some not
here is my code that i get the page source:
(NSString *)getStringFromUrl:(NSString *)url{
NSError *err = nil;
NSString *agentString = #"Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10_5_6; en-us) AppleWebKit/525.27.1 (KHTML, like Gecko) Version/3.2.1 Safari/525.27.1";
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:
[NSURL URLWithString:url]];
[request setValue:agentString forHTTPHeaderField:#"User-Agent"];
NSData *data = [ NSURLConnection sendSynchronousRequest:request returningResponse: nil error: &err ];
NSString *returnData = [[NSString alloc] initWithBytes: [data bytes] length:[data length] encoding: NSUTF8StringEncoding];
if (err!=nil)
NSLog(#"error message: %#",err.description);
return returnData;
}
link that worked for me:
http://50.22.211.228:8000/played.html
link that not worked for me and return nil in returnData:
http://107.150.5.94:7070/played.html

Answer 1

The issue appears to be that the second request is apparently not returning valid NSUTF8StringEncoding. If you look at the NSData itself (if you log that, you'll see the hexadecimal representation of the binary payload), you are receiving data, but it's the conversion to a NSString that is failing.
If you look at that page in a web browser, it gets confused, too (the characters don't make sense). I'd wager that they are not writing a valid UTF8 string in that HTML, though it's not immediately obvious what precisely they're doing (it doesn't appear to be a string encoding that I recognize).
You can use NSASCIIStringEncoding to see the same mess in your code that you'll see in your web browser.

Answer 2

I use the following to get the source code of a web page as NSString:
NSError *error = nil;
NSString *urlString = [NSString stringWithFormat:#"%#", #"http://www.google.es"];
NSURL *url = [NSURL URLWithString:[urlString stringByAddingPercentEscapesUsingEncoding:NSASCIIStringEncoding]];
NSString *webSource = [NSString stringWithContentsOfURL:url encoding:NSASCIIStringEncoding error:&error];
I hope this helps you and is what you are looking for.