Retrieve videos for YouTube playlist

[revojoel]

I am successfully retrieving an array of playlists but I am at a loss
for how to retrieve the videos in the playlist.

- (void)viewDidLoad {
// construct the feed url
NSURL *feedURL = [GDataServiceGoogleYouTube
youTubeURLForUserID:kYouTubeUserID userFeedID:uploadsID];

NSLog(@"DEBUG:Start animating"); //DEBUG
[activityIndicator startAnimating];

[service fetchFeedWithURL:feedURL
delegate: self

didFinishSelector:@selector(allPlayListsFetchTicket:finishedWithFeed:error:)];
}

- (void)allPlayListsFetchTicket:(GDataServiceTicket *)ticket
finishedWithFeed:(GDataFeedBase *)aFeed
error:(NSError *)error {

self.feed = (GDataFeedYouTubeVideo *)aFeed;

[self.tableView reloadData];

}


I can get a GDataEntryYouTubePlaylist object from each object in the
feed.

NSArray *entries = [feed entries];

for (int i=0; i < [entries count] ; i++) {

GDataEntryBase *entry = [entries objectAtIndex:i];
GDataTextConstruct *titleTextConstruct = [entry title];
NSString *title = [titleTextConstruct stringValue];
GDataEntryYouTubePlaylist *playlist = (GDataEntryYouTubePlaylist
*)entry;
NSString *playlistURL = [[playlist alternateLink] href];
NSString *playListContentElementURL = [[[playlist content]
sourceURL]
absoluteString];
}

I just do not understand which service method to use for pulling a
feed of playlists. I've tried some combinations but have had no
success.

Does anyone have an example or guidance.

Thanks for you help.

revojoel

[Greg Robbins]

For a user, you can fetch the feed of playlist links; each of those has the URL to a playlist, which contains video entries.

- (void)fetchPlaylistLinksFeed {

  NSURL *feedURL = [GDataServiceGoogleYouTube youTubeURLForUserID:kGDataServiceDefaultUser

    userFeedID:kGDataYouTubeUserFeedIDPlaylists];

  GDataServiceGoogleYouTube *service = [self youTubeService];

  GDataServiceTicket *ticket = [service fetchFeedWithURL:feedURL

    delegate:self

    didFinishSelector:@selector(playlistLinksTicket:finishedWithFeed:error:)];

}

- (void)playlistLinksTicket:(GDataServiceTicket *)ticket

    finishedWithFeed:(GDataFeedYouTubePlaylistLink *)feed

    error:(NSError *)error {

  // fetch the user's first playlist

  GDataEntryYouTubePlaylistLink *entry = [feed firstEntry];

  [self fetchPlaylistLink:entry];

}

- (void)fetchPlaylistLink:(GDataEntryYouTubePlaylistLink *)entry {

  GDataServiceGoogleYouTube *service = [self youTubeService];

  NSURL *playlistFeedURL = [[entry content] sourceURL];

  GDataServiceTicket *ticket = [service fetchFeedWithURL:playlistFeedURL

    delegate:self

    didFinishSelector:@selector(playlistTicket:finishedWithFeed:error:)];

}  

                        

- (void)playlistTicket:(GDataServiceTicket *)ticket

    finishedWithFeed:(GDataFeedYouTubePlaylist *)feed

    error:(NSError *)error {

  NSLog(@"feed=%@", feed);

  NSLog(@"video entries=%@", [feed entries]);

}  

[Jonathan Lundell]

(OK, it's a belated reply...)

When I run the sample code, the returned video entries are GDataEntryBase; I expected them to be GDataEntryYouTubeVideo or GDataEntryYouTubePlaylist. Consequently, media:group isn't parsed. (FWIW, I used the user @"TEDtalksDirector" in my test case.)

[Greg Robbins]

The library instantiates GDataEntryBase for entries when the needed entry class is not compiled and linked into the application.

That can happen if the entry source file is missing from the project, the GDATA_INCLUDE_YOUTUBE_SERVICE preprocessor value is not defined, or the linker is excluding unreferenced classes because the target lacks the -ObjC or -all_load linker flags.

[Jonathan Lundell]

On Feb 19, 2012, at 9:45 PM, Greg Robbins wrote:
> The library instantiates GDataEntryBase for entries when the needed entry class is not compiled and linked into the application.
>
> That can happen if the entry source file is missing from the project, the GDATA_INCLUDE_YOUTUBE_SERVICE preprocessor value is not defined, or the linker is excluding unreferenced classes because the target lacks the -ObjC or -all_load linker flags.
>

Thanks.

For the benefit of future generations: I'm building a static library selectively for the YouTube service only, and linking that with my app. Adding -all_load to the apps linker flags fixed my problem.

[Suleman Imdad]

Hi 

Can you please share an example project where I can retrieve all videos from a Youtube playlist that can play back to back?

Thanks, 

Suleman.