Same code showing different behaviour in XCode - ios

Question

-(IBAction)onButtonClick:(id)sender
{
DowloadFilesManager* downManager1=[[DowloadFilesManager alloc] init];
DowloadFilesManager* downManager2=[[DowloadFilesManager alloc] init];
DowloadFilesManager* downManager3=[[DowloadFilesManager alloc] init];
[downManager1 downloadURL:#"http://localhost/banners/banner1.jpg" destPath:#"/Users/varunisac/Desktop/samples/godisgreat.jpg"];
[downManager2 downloadURL:#"http://localhost/banners/banner1.jpg" destPath:#"/Users/varunisac/Desktop/samples/godisgreat1.jpg"];
[downManager3 downloadURL:#"http://localhost/banners/banner1.jpg" destPath:#"/Users/varunisac/Desktop/samples/godisgreat2.jpg"];
NSLog(#"Finished Succesfully");
}
1)The Above code works Perfect
2) It downloads the jpgs after firing the following event function.
- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
NSLog(#"Succeeded! Received %d bytes of data",[receivedData length]);
[receivedData writeToFile:toFile atomically:YES];
theConnection = nil;
receivedData = nil;
}
But It DOES NOT fires any event methods while i tried on another programme after importing the "DowloadFilesManager.h" and "DowloadFilesManager.m" which runs on the same XCode on the same Mac machine with the server URLs reachable.Can anyone suggest a solution ? Am i missing anything? I tried Clean etc...but doesnt work. Following is the DowloadFilesManager class which i used:
#import "DowloadFilesManager.h"
#implementation DowloadFilesManager
#synthesize toFile;
#synthesize toURL;
#synthesize theConnection;
-(void) downloadURL:(NSString *) urlStr destPath:(NSString *) destPath
{
toURL=urlStr;
toFile=destPath;
// Create the request.
NSURLRequest *theRequest=[NSURLRequest requestWithURL:[NSURL URLWithString:toURL]
cachePolicy:NSURLRequestUseProtocolCachePolicy
timeoutInterval:60.0];
receivedData = [[NSMutableData alloc] init];
// Create the NSMutableData to hold the received data.
// receivedData is an instance variable declared elsewhere.
// [receivedData dataWithCapacity: 0];
// create the connection with the request
// and start loading the data
NSURLConnection *theConnection=[[NSURLConnection alloc] initWithRequest:theRequest delegate:self];
if (!theConnection) {
// Release the receivedData object.
receivedData = nil;
// Inform the user that the connection failed.
}
}
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
[receivedData setLength:0];
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
// Append the new data to receivedData.
// receivedData is an instance variable declared elsewhere.
[receivedData appendData:data];
}
- (void)connection:(NSURLConnection *)connection
didFailWithError:(NSError *)error
{
theConnection = nil;
receivedData = nil;
// inform the user
NSLog(#"Connection failed! Error - %# %#",
[error localizedDescription],
[[error userInfo] objectForKey:NSURLErrorFailingURLStringErrorKey]);
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
NSLog(#"Succeeded! Received %d bytes of data",[receivedData length]);
[receivedData writeToFile:toFile atomically:YES];
theConnection = nil;
receivedData = nil;
}
#end

Answer 1

Within - (void)downloadURL:destPath:, you have created a local variable called theConnection:
NSURLConnection *theConnection = [...];
and when the method ends, this will go out of scope and be destroyed.
What you want is the following, to use your property to persist the connection object:
self.theConnection = [...];
Also, a better approach to signal failure would be to make that method return BOOL and use this statement:
return self.theConnection != nil;