download-url of GTLDriveFile coming nil and even GTLDriveFileExportLinks coming nil - ios

Question

I want to download the files from google-drive. I have fetched the GTLDriveFile objects from a drive. But downloadUrl property of these file objects are nil.
Googling more, i got that file.exportLinks also has download links. But that is also coming nil.
I used this code to fetch files:
- (void)fetchFiles {
GTLQueryDrive *query =
[GTLQueryDrive queryForFilesList];
query.maxResults = 10;
[self.service executeQuery:query
delegate:self
didFinishSelector:#selector(displayResultWithTicket:finishedWithObject:error:)];
}
- (void)displayResultWithTicket:(GTLServiceTicket *)ticket
finishedWithObject:(GTLDriveFileList *)files
error:(NSError *)error {
if (error == nil) {
if (files.items.count > 0) {
fileArr=files.items;
}
}
}
here fileArr has the files of class GTLFileDrive.
From Google-drive developer site, i got the following code snippet to download file using a parameter Url:
GTMHTTPFetcher *fetcher = [self.service.fetcherService fetcherWithURLString: urlOfFile];
[fetcher beginFetchWithCompletionHandler:^(NSData *data, NSError *error) {
if (error == nil) {
NSLog(#"Retrieved file content");
// Do something with data
} else {
NSLog(#"An error occurred: %#", error);
}
}];
I need the urlOfFile to complete the task.
Any help would be greatly appreciated.

Answer 1

When you do your initial auth, you need to request the right scope - otherwise, you only get rights to list the files, and not download them.
Something like.
NSArray *scopes = [NSArray arrayWithObjects:kGTLAuthScopeDrive, nil];
authController = [[GTMOAuth2ViewControllerTouch alloc]
initWithScope:[scopes componentsJoinedByString:#" "]
clientID:self.clientId
clientSecret:self.clientSecret
keychainItemName:kKeychainItemName
delegate:self
finishedSelector:#selector(viewController:finishedWithAuth:error:)];
You can see this all in my new Google Drive Picker
https://github.com/ConfusedVorlon/HSGoogleDrivePicker