calendarVC

#import "CalendarViewController.h"


@interface CalendarViewController ()


@end

@implementation CalendarViewController {
    NSMutableData* receivedData;
    NSURLConnection *theConnection;
}
@synthesize scheduleImage;



- (void)viewDidLoad {
    [super viewDidLoad];
//    NSCache *memoryCache = [[NSCache alloc] init];
//    [self secondAttempt];
//    [self presentImage:[NSURL URLWithString:@"http://upload.wikimedia.org/wikipedia/commons/4/47/PNG_transparency_demonstration_1.png"]];
    [self fifthAttempt];
//    [self displayImage];
       // Do any additional setup after loading the view.
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}


// To display the image straight from the URL
// This displays an image, but it doesnt save it
-(void)presentImage:(NSURL*)imageURL {
    NSData *imageData = [NSData dataWithContentsOfURL:imageURL];
    UIImage *image = [UIImage imageWithData:imageData scale:2.0];
    [self.scheduleImage setImage: image];
}




- (void) displayImage {
    NSURL * imageURL = [NSURL fileURLWithPath:@"receivedData"];
    NSData * imageData = [NSData dataWithContentsOfURL:imageURL];
    UIImage * image = [UIImage imageWithData:imageData];
    [scheduleImage setImage:image];
}


- (void)secondAttempt {
    NSCache *memoryCache = [[NSCache alloc] init]; //assume there is a memoryCache for images or videos

    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND, 0), ^{

        NSString *urlString = @"http://upload.wikimedia.org/wikipedia/commons/4/47/PNG_transparency_demonstration_1.png";

        NSData *downloadedData = [NSData dataWithContentsOfURL:[NSURL URLWithString:urlString]];

        if (downloadedData) {

            // STORE IN FILESYSTEM
            NSString* cachesDirectory = [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) objectAtIndex:0];
            NSString *file = [cachesDirectory stringByAppendingPathComponent:urlString];
            [downloadedData writeToFile:file atomically:YES];

            // STORE IN MEMORY
            [memoryCache setObject:downloadedData forKey:@"downloadedPic"];
        }

        // NOW YOU CAN CREATE AN AVASSET OR UIIMAGE FROM THE FILE OR DATA
        NSURL *imageURL = [NSURL fileURLWithPath:@"downloadedPic"];
        NSData *imageData = [NSData dataWithContentsOfURL:imageURL];
        UIImage *image = [UIImage imageWithData:imageData];
        [scheduleImage setImage:image];
        });
}

/*
#pragma mark - Navigation

// In a storyboard-based application, you will often want to do a little preparation before navigation
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
    // Get the new view controller using [segue destinationViewController].
    // Pass the selected object to the new view controller.
}
*/


#pragma from https://developer.apple.com/library/ios/documentation/Cocoa/Conceptual/URLLoadingSystem/Tasks/UsingNSURLConnection.html#//apple_ref/doc/uid/20001836-BAJEAIEE

- (void)fifthAttempt {
    // Create the request.
    NSURLRequest *theRequest=[NSURLRequest requestWithURL:[NSURL URLWithString:@"http://upload.wikimedia.org/wikipedia/commons/4/47/PNG_transparency_demonstration_1.png"]
                                              cachePolicy:NSURLRequestUseProtocolCachePolicy
                                          timeoutInterval:60.0];

    // Create the NSMutableData to hold the received data.
    // receivedData is an instance variable declared elsewhere.
    receivedData = [NSMutableData 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 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
{
    // Release the connection and the data object
    // by setting the properties (declared elsewhere)
    // to nil.  Note that a real-world app usually
    // requires the delegate to manage more than one
    // connection at a time, so these lines would
    // typically be replaced by code to iterate through
    // whatever data structures you are using.
    theConnection = nil;
    receivedData = nil;

    // inform the user
    NSLog(@"Connection failed! Error - %@ %@",
          [error localizedDescription],
          [[error userInfo] objectForKey:NSURLErrorFailingURLStringErrorKey]);
}

- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
    // do something with the data
    // receivedData is declared as a property elsewhere
    NSLog(@"Succeeded! Received %d bytes of data",[receivedData length]);

    // Release the connection and the data object
    // by setting the properties (declared elsewhere)
    // to nil.  Note that a real-world app usually
    // requires the delegate to manage more than one
    // connection at a time, so these lines would
    // typically be replaced by code to iterate through
    // whatever data structures you are using.
    theConnection = nil;
    receivedData = nil;
}













#pragma mark What I started off with
- (void)doThisTask {
// For this snippet we are downloading the same in two tasks.
NSString *imageUrl = @"http://upload.wikimedia.org/wikipedia/commons/4/47/PNG_transparency_demonstration_1.png";
// You always start by creating an NSURLConfiguration.
NSURLSessionConfiguration *sessionConfig = [NSURLSessionConfiguration defaultSessionConfiguration];
// This creates a session using the current class as a delegate.
NSURLSession *session = [NSURLSession sessionWithConfiguration:sessionConfig
                                                      delegate:self
                                                 delegateQueue:nil];
//Tasks are always created by sessions. This one is created with the block-based method. Remember you could still use the NSURLSessionDownloadDelegate to track download progress.
NSURLSessionDownloadTask *getImageTask = [session downloadTaskWithURL:[NSURL URLWithString:imageUrl]
                                                    completionHandler:^(NSURL *location, NSURLResponse *response, NSError *error) {
                                                        // Here you use the location variable provided in the completion handler to get a pointer to the image
                                                        UIImage *downloadedImage = [UIImage imageWithData:[NSData dataWithContentsOfURL:location]];
                                                        // Finally you could, for example, update UIImageView’s image to show the new file.
                                                        dispatch_async(dispatch_get_main_queue(), ^{
                                                            // do stuff with image
                                                            _imageWithBlock.image = downloadedImage;
                                                        });
                                                    }];

// You always have to start up the task!
[getImageTask resume];
}



// if you needed to track the download progress, for either task creation method, you would need to use the following:
-(void)URLSession:(NSURLSession *)session
     downloadTask:(NSURLSessionDownloadTask *)downloadTask
     didWriteData:(int64_t)bytesWritten
totalBytesWritten:(int64_t)totalBytesWritten
totalBytesExpectedToWrite:(int64_t)totalBytesExpectedToWrite
{
    NSLog(@"%f / %f", (double)totalBytesWritten,
          (double)totalBytesExpectedToWrite);
}

@end