generate dartisans from playlist, keep everything up to date

scripts/gen_dartisans_playlist.dart

+import 'dart:json';
+import 'dart:io';
+import 'dart:uri';
+
+final String YT_PLAYLIST_URL = 'http://gdata.youtube.com/feeds/api/playlists/';
+final String PLAYLIST_ID = 'PLOU2XLYxmsIIS2zgjdmBEwTrA6m5YgHBs';
+
+final String OUTPUT_FILENAME = 'src/site/dartisans/episodes.yaml';
+
+Future<String> loadDartisansPlaylist() {
+  var completer = new Completer();
+  var client = new HttpClient();
+  var conn = client.getUrl(new Uri('$YT_PLAYLIST_URL$PLAYLIST_ID?alt=json'));
+  conn.onResponse = (HttpClientResponse resp) {
+    var buffer = new StringBuffer();
+    var input = resp.inputStream;
+    input.onData = () => buffer.add(new String.fromCharCodes(input.read()));
+    input.onClosed = () {
+      print('Done loading JSON from API');
+      client.shutdown();  // XXX do this or the app remains running
+      completer.complete(buffer.toString());
+    };
+    input.onError = (e) {
+      completer.completeException("ERROR reading from input: $e");
+    };
+  };
+  conn.onError = (e) {
+    completer.completeException("ERROR CONNECTING TO YT: $e");
+  };
+  return completer.future;
+}
+
+Map parsePlaylistJson(String json) => JSON.parse(json);
+
+writePlaylistYaml(Directory directory, Map playlist) {
+  var episodeOffset = 2;
+  var file = new File('${directory.path}/../$OUTPUT_FILENAME');
+  var output = file.openOutputStream();
+  output.writeString("""
+# DO NOT EDIT THIS FILE - IT IS AUTOGENERATED
+# See scripts/gen_dartisans_playlist.dart
+url-prefix: http://commondatastorage.googleapis.com/dartlang-podcast/
+episodes:
+""");
+  var entries = playlist['feed']['entry'];
+  for (var i = 0; i < entries.length; i++) {
+    var epNum = entries.length - i + episodeOffset;
+    writeEntry(output, entries[i], epNum);
+  }
+  output.close();
+}
+
+writeEntry(OutputStream out, Map entry, int epNum) {
+  String playerUrl = entry[r'media$group'][r'media$player'][0]['url'];
+  String youtubeId = new RegExp("v=(.*)&").firstMatch(playerUrl)[1];
+  String title = entry['title'][r'$t'];
+  String subtitle;
+  Match match = new RegExp(r": (.*)$").firstMatch(title);
+  if (match == null) {
+    print("Title '$title' does not have a :");
+    return;
+  } else {
+    subtitle = match[1];
+  }
+  String thumbnail = entry[r'media$group'][r'media$thumbnail'][0]['url'];
+  String recorded;
+  if (entry[r'yt$recorded'] == null) {
+    print("No explicit recorded date for $title. Please set.");
+    return;
+  } else {
+    recorded = entry[r'yt$recorded'][r'$t'];
+  }
+  String desc = entry['content'][r'$t']
+                  .replaceAll("\n", ' ')
+                  .replaceAll('"', "'");
+  
+  out.writeString("""
+- title: "${title}"
+  subtitle: "${subtitle}"
+#  file: unknown.mp3
+  pubdate: ${recorded}
+  description: "${desc}"
+#  length: 21815187
+  num: $epNum
+  youtubeid: $youtubeId
+  thumbnail: $thumbnail
+""");
+}
+
+main() {
+  var script = new File(new Options().script);
+  var directory = script.directorySync();
+  
+  loadDartisansPlaylist()
+  .then((String json) {
+    Map data = parsePlaylistJson(json);
+    writePlaylistYaml(directory, data);
+    print("Complete!");
+  });
+}