public static void IsSet(this Assert assert, VideoInfoSnippet videoInfoSnippet)
{
Assert.IsNotNull(videoInfoSnippet);
Assert.That.IsNotBlank(videoInfoSnippet.Id);
Assert.That.IsNotBlank(videoInfoSnippet.Title);
Assert.IsNotNull(videoInfoSnippet.Description);
Assert.IsNotNull(videoInfoSnippet.Keywords);
}
/// <summary>
/// Gets playlist info by ID, truncating resulting video list at given number of pages (1 page ≤ 200 videos)
/// </summary>
public async Task <PlaylistInfo> GetPlaylistInfoAsync(string playlistId, int maxPages)
{
if (playlistId == null)
{
throw new ArgumentNullException(nameof(playlistId));
}
if (!ValidatePlaylistId(playlistId))
{
throw new ArgumentException("Invalid Youtube playlist ID", nameof(playlistId));
}
if (maxPages <= 0)
{
throw new ArgumentOutOfRangeException(nameof(maxPages), "Needs to be a positive number");
}
// Get all videos across pages
int pagesDone = 0;
int offset = 0;
XElement playlistInfoXml;
var videos = new List <VideoInfoSnippet>();
var videoIds = new HashSet <string>();
do
{
// Get
string request = $"https://www.youtube.com/list_ajax?style=xml&action_get_list=1&list={playlistId}&index={offset}";
string response = await _httpService.GetStringAsync(request).ConfigureAwait(false);
playlistInfoXml = XElement.Parse(response).StripNamespaces();
// Parse videos
int total = 0;
int delta = 0;
foreach (var videoInfoSnippetXml in playlistInfoXml.Elements("video"))
{
// Basic info
string videoId = videoInfoSnippetXml.ElementStrict("encrypted_id").Value;
string videoTitle = videoInfoSnippetXml.ElementStrict("title").Value;
string videoDescription = videoInfoSnippetXml.ElementStrict("description").Value;
long videoViewCount = Regex.Replace(videoInfoSnippetXml.ElementStrict("views").Value, @"\D", "")
.ParseLong();
long videoLikeCount = Regex.Replace(videoInfoSnippetXml.ElementStrict("likes").Value, @"\D", "")
.ParseLong();
long videoDislikeCount = Regex.Replace(videoInfoSnippetXml.ElementStrict("dislikes").Value, @"\D", "")
.ParseLong();
// Keywords
string videoKeywordsJoined = videoInfoSnippetXml.ElementStrict("keywords").Value;
var videoKeywords = Regex
.Matches(videoKeywordsJoined, @"(?<=(^|\s)(?<quote>""?))([^""]|(""""))*?(?=\<quote>(?=\s|$))")
.Cast <Match>()
.Select(m => m.Value)
.Where(s => s.IsNotBlank());
var snippet = new VideoInfoSnippet(videoId, videoTitle, videoDescription, videoKeywords,
videoViewCount, videoLikeCount, videoDislikeCount);
// Add to list if not already there
if (videoIds.Add(snippet.Id))
{
videos.Add(snippet);
delta++;
}
total++;
}
// Break if the videos started repeating
if (delta <= 0)
{
break;
}
// Prepare for next page
pagesDone++;
offset += total;
} while (pagesDone <= maxPages);
// Parse metadata
string title = playlistInfoXml.ElementStrict("title").Value;
string author = playlistInfoXml.Element("author")?.Value ?? "";
string description = playlistInfoXml.ElementStrict("description").Value;
long viewCount = (long)playlistInfoXml.ElementStrict("views");
return(new PlaylistInfo(playlistId, title, author, description, viewCount, videos));
}
