NSURLConnection in a Background Thread

Russell — Sat, 09 Jul 2011 18:00:24 +0000

Just a quick post to highlight a little issue I was having getting tiles to load from the internet for the campus map in the YUSU iPhone app.

Basically, getting an NSURLConnection to load something asynchronously in a background thread requires a bit of extra work than running it in the main thread (which I needed to do as the CATiledLayer I use loads tiles in the background).

The problem arises from the background thread stopping before the NSURLConnection actually gets any response. Luckily it's pretty easy to force a thread/run loop to keep running with CFRunLoopRun(). Just don't forget to stop it when you're done with CFRunLoopStop(CFRunLoopGetCurrent()).

Here's some sample code:

- (void)startLoadWithURL:(NSURL *)url {
NSURLRequest *request = [NSURLRequest requestWithURL:url];
[NSURLConnection connectionWithRequest:request delegate:self];
CFRunLoopRun();
}

- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
// Do something with the finished connection
CFRunLoopStop(CFRunLoopGetCurrent());
}

- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error {
// Handle the error
CFRunLoopStop(CFRunLoopGetCurrent());
}

“Hello, world”

Russell — Sat, 09 Jul 2011 14:01:47 +0000

Today I thought it was probably about time to start using this blog, which I set up nearly a year ago now, to actually post some things.

I imagine they'll mostly be about programming - mainly trying to deal with problems I come across and can't find any other help about, although maybe some little tutorials too. We'll see.

Anyway, if anyone's actually reading this, thanks and see you soon.

fullstop.

NSURLConnection in a Background Thread

“Hello, world”