Stop the nextprocess when network connection fails - iphone

Question

I'm taking xml response from service url and I want to display error, when network connection fails. So I display the UIAlertView, but this alertView is getting displayed after the rest of process is completed. I want it to be shown immediately.
In android, if network connection fails, it will display an error alert that "Unfortunately app name has terminated". Is there anything of such for iPhone? If not I want to show alertview and stop the rest of the process.
This is the code I'm working on:
if (responseData!= NULL)
{
response = [[NSString alloc] initWithData:responseData
encoding:NSUTF8StringEncoding ];
NSLog(#"Response Code:%d",[urlResponse statusCode]);
if([urlResponse statusCode ]>=200 && [urlResponse statusCode]<300)
{
NSLog(#"Response:%#",response);
}
}
else
{
NSLog(#"Failed to send request: %#", [error localizedDescription]);
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"Unfornately stopped.Try Again " message:#"" delegate:self cancelButtonTitle:#"OK" otherButtonTitles:nil, nil];
[alert show];
[alert release];
}
parser =[[NSXMLParser alloc]initWithData:responseData];
[parser setDelegate:self];
[parser setShouldProcessNamespaces:NO];
[parser setShouldReportNamespacePrefixes:NO];
[parser setShouldResolveExternalEntities:NO];
currentHtmlElement=#"1";
[parser parse];
[parser release];
In my code if it fails to send request, then NSLog gets printed and alertView code is executed. At the same time I want to stop the rest of the process i.e initialising a parser and doing the rest of operation.
How can I do it?

Answer 1

Very simple... Move your parse code inside if block.
if (responseData!= NULL)
{
response = [[NSString alloc] initWithData:responseData
encoding:NSUTF8StringEncoding ];
NSLog(#"Response Code:%d",[urlResponse statusCode]);
if([urlResponse statusCode ]>=200 && [urlResponse statusCode]<300)
{
NSLog(#"Response:%#",response);
}
parser =[[NSXMLParser alloc]initWithData:responseData];
[parser setDelegate:self];
[parser setShouldProcessNamespaces:NO];
[parser setShouldReportNamespacePrefixes:NO];
[parser setShouldResolveExternalEntities:NO];
currentHtmlElement=#"1";
[parser parse];
[parser release];
}
else
{
NSLog(#"Failed to send request: %#", [error localizedDescription]);
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"Unfornately iCloudBiz has stopped.Try Again " message:#"" delegate:self cancelButtonTitle:#"OK" otherButtonTitles:nil, nil];
[alert show];
[alert release];
}
By the way... You mentioned your Android's app behavior as follows
In android if network connection fails it will display an error alert that Unfortunatly app name has terminated.
Please understand that this behavior is an abnormal behavior. This is called a CRASH and you should handle this appropriately. If network is disconnected app should display a message without terminating/crashing :)

Answer 2

You should use Reachability class to check for whether internet connection is available or not
this is sample code to understand how it works
Reachability *reachability = [Reachability reachabilityForInternetConnection];
NetworkStatus internetStatus = [reachability currentReachabilityStatus];
if (internetStatus != NotReachable) {
//my web-dependent code
}
else {
//there-is-no-connection warning
}