ASIHTTPRequest problems on iPhone (memory?) - nsurlconnection

Question

I am using ASIHTTPRequest on the iPhone to make a call to the server, which then sends a response containing a JSON file. I got it working on a basic level, but when I added it to my project, and made a call to the server, my app started crashing with bad_access.
I make the call from viewDidLoad as such:
requestModel = [[RequestModel alloc]init];
NSURL *url = [[NSURL URLWithString:#"myURL"]retain];
[requestModel eventsRequestFor:#"myUsername" password:#"myPassword" forURL:url];
This calls a function in another class called RequestModel, and I go through and try to unpack the returned array as such (a lot of code):
-(void)eventsRequestFor:(NSString*)username password:(NSString*)password forURL:(NSURL*)forURL {
//use ASIHTTPRequest to post to sever. Here you authenticate and recieve answer
ASIHTTPRequest *request = [ASIHTTPRequest requestWithURL:forURL];
[request setUsername:username];
[request setPassword:password];
[request setDelegate:self];
[request setDidFailSelector:#selector(uploadFailed:)];
[request setDidFinishSelector:#selector(uploadFinished:)];
[request startAsynchronous];
[request release];
NSLog(#"Model called");
}
#pragma mark Model Delegates
- (void)uploadFinished:(ASIHTTPRequest *)request {
// Use when fetching text data
NSLog(#"upload start");
NSString *stringFromRequest = [[NSString alloc]init];
stringFromRequest = [request responseString];
[self buildArrayFromRequest:stringFromRequest];
//[stringFromRequest release];
}
- (void)uploadFailed:(ASIHTTPRequest *)request {
NSString *statusMessage = [request responseStatusMessage];
NSLog(#"%#",statusMessage);
NSError *error = [request error];
NSLog(#"%#",error);
}
-(void)buildArrayFromRequest:(NSString*)string {
NSArray *arrayFromData = [[NSArray alloc]init];
arrayFromData = [string yajl_JSON];
NSLog(#"This is the array from the JSON %#",[arrayFromData objectAtIndex:0]);
NSMutableArray *events = [[NSMutableArray alloc] init];
for(int i= 0; i < [arrayFromData count];i++)
{
/////code to unpack array
}
///here i try to populate table with unpacked array
FirstViewController *firstVC = [[FirstViewController alloc]init];
[firstVC createTableWithArray:events];
[firstVC release];
[arrayFromData release];
[events release];
}
Any ideas on where I am going wrong? It seems like I am releasing an object that has already been released, but I can't find it.

Answer 1

EDIT: You're releasing an NSData that's not yours.
You don't need this line :
[arrayFromData release];
because of this mistake :
You have put :
NSArray *arrayFromData = [[NSArray alloc]init];
arrayFromData = [string yajl_JSON];
when all you need is this :
NSArray *arrayFromData = [string yajl_JSON]; // This doesn't need releasing
You're releasing a request that's already autoreleased :(
// Create an autoreleased request object
ASIHTTPRequest *request = [ASIHTTPRequest requestWithURL:forURL];
...
[request release]; // fail here - this line is not needed
Just FYI :
This is unneeded code :
NSString *stringFromRequest = [[NSString alloc]init];
stringFromRequest = [request responseString];
You are making a string object and then getting a different one. The first one you're making will be leaked. This code will do what you want :
NSString *stringFromRequest = [request responseString]; // This doesn't need releasing :)
However, it's the cause of a leak, not the crash that you are reporting.
(You've got this pattern in other places in your code, not just here.)