iOS: How to perform NSURLConnection and get repsonse before continuing? - asp.net

Question

I'm trying to get updates from my server. I want it to have the latest information though so I'm running a page and if the response is "Complete" and not "Error" then I will proceed with the Update methods to get the latest information from the xml file. My problem is the Delegate methods are not getting called until all my code in my "Main" function is completed. By that time the code has already gone past my if statement checking if the responseSuccess is TRUE or FALSE. I think its because the NSURLConnection is asynchronous... yet im not sure how to fix it. If I need to provide more code/information just let me know. Thanks!
Main
if (UpdatingFlag)
{
NSLog(#"Cannot update while updating is in process...");
} else {
// run updates before getting information
[self getResponse:#"http://url/path/to/file?function=myvalue"];
[self setBottomBarToUpdating:#"Processing Please Wait..."];
dispatch_queue_t queue = dispatch_queue_create("updateQueue", DISPATCH_QUEUE_CONCURRENT);
UpdatingFlag = TRUE;
if(responseSuccess)
{
dispatch_async(dispatch_get_main_queue(),^ {
[self setBottomBarToUpdating:#"Updating..."];
[self updateFromXMLFile:#"https://url/path/to/file.xml"];
});
}
UpdatingFlag = FALSE;
dispatch_barrier_async(queue,^ {
dispatch_async(dispatch_get_main_queue(), ^{
[self setBottomBarToUpdated];
});
});
}
GetReponse Method
- (void) getResponse:(NSString *)url
{
NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:url]
cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:45.0];
NSURLConnection *connection = [[NSURLConnection alloc] initWithRequest:request delegate:self];
[connection start];
if (connection) {NSLog(#"Connecting...");
} else {NSLog(#"Didn't Connect Error...");}
}
Delegate Methods
#pragma mark NSURLConnection methods
- (void)connection:(NSURLConnection *)conn didReceiveAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge {
NSLog(#"Did Receive Challenge");
if ([challenge previousFailureCount] == 0) {
NSURLCredential *newCredential;
newCredential = [NSURLCredential credentialWithUser:#"user" password:#"pass" persistence:NSURLCredentialPersistenceNone];
[[challenge sender] useCredential:newCredential forAuthenticationChallenge:challenge];
} else {
[[challenge sender] cancelAuthenticationChallenge:challenge];
NSLog(#"Invalid Username and Password");
UIAlertView * userNameAlert = [[UIAlertView alloc]initWithTitle:#"Error"
message:#"ErrorMsg"
delegate:self
cancelButtonTitle:nil
otherButtonTitles:#"OK", nil];
[userNameAlert show];
}
}
- (void)connection:(NSURLConnection *)conn didReceiveData:(NSData *)data {
NSLog(#"Received Data Packet...");
response = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
}
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{
NSLog(#"Error, %#", error);
}
- (void)connectionDidFinishLoading:(NSURLConnection *)conn {
NSLog(#"Finished Loading");
if([response rangeOfString:#"Complete"].location == NSNotFound) {
// success
responseSuccess = FALSE;
} else {
// failed
responseSuccess = TRUE;
}
}
- (BOOL)connection:(NSURLConnection *)conn canAuthenticateAgainstProtectionSpace:(NSURLProtectionSpace *)protectionSpace {
return YES;
}

Answer 1

Any code you want to run after the you get the update from your server needs to be moved to (or called from) the connectionDidFinishLoading: method. So, you can get rid of the flags, and only have the getResponse call in your main code.