[[DPFileDownloader sharedDownloader] addFileDownloaderObserver:self];

NSURL*        URL;
NSURLRequest* req  = [NSURLRequest requestWithURL:URL];
NSString*     dirName;
NSString*     fileName;

DPFileDownloadTask* task   = [[DPFileDownloadTask alloc] initWithURLRequest:req];
[task addFileDownloadTaskObserver:self];
task.delegate = self;
task.expectedDirectoryPath = dirName;
task.expectedFileName      = fileName;
[[DPFileDownloader sharedDownloader] enqueueFileDownloadTask:task];

#pragma mark - DPFileDownloaderObserving

- (void)fileDownloader:(DPFileDownloader*)fileDownloader didUpdateOperationOfFileDownloadTask:(DPFileDownloadTask*)task
{

}

#pragma mark - DPFileDownloadTaskObserving

- (void)fileDownloadTaskDidChangeState:(DPFileDownloadTask*)fileDownloadTask beforeState:(DPFileDownloadTaskState)beforeState
{

}

- (void)fileDownloadTaskDidUpdateProgress:(DPFileDownloadTask*)fileDownloadTask
{

}

#pragma mark - DPFileDownloadTaskDelegate

- (void)fileDownloadTask:(DPFileDownloadTask*)fileDownloadTask didFinishDownloadToTemporaryLocation:(NSURL*)location
{

}

NSArray*  paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString* documentDirectoryPath = paths[0];

[self.navigationController pushViewController:[DPFileListViewController rootFileListViewController] animated:YES];