Add channel api

.gitignore

@@ -13,3 +13,4 @@ doc/api/
 .idea/
 .vscode/
 *.iml
+bin/

lib/src/cipher/cipher.dart

@@ -1,7 +1,7 @@
 library youtube_explode.cipher;
 
 import 'package:http/http.dart' as http;
-import '../extensions.dart';
+import '../extensions/helpers_extension.dart';
 import 'cipher_operations.dart';
 
 final _deciphererFuncNameExp = RegExp(

lib/src/extensions/channel_extension.dart

@@ -0,0 +1,140 @@
+import 'package:html/dom.dart';
+import 'package:html/parser.dart' as html;
+
+import '../models/models.dart';
+import '../youtube_explode_base.dart';
+import 'helpers_extension.dart';
+import 'playlist_extension.dart';
+
+/// Channel extension for YoutubeExplode
+extension ChannelExtension on YoutubeExplode {
+  static final _usernameRegMatchExp =
+      RegExp(r'youtube\..+?/user/(.*?)(?:\?|&|/|$)');
+
+  static final _idRegMatchExp =
+      RegExp(r'youtube\..+?/channel/(.*?)(?:\?|&|/|$)');
+
+  /// Returns the [Channel] associated with the given channelId.
+  /// Throws an [ArgumentError] if the channel id is not valid.
+  Future<Channel> getChannel(String channelId) async {
+    if (!validateChannelId(channelId)) {
+      throw ArgumentError.value(
+          channelId, 'channelId', 'Invalid YouTube channel id.');
+    }
+
+    var channelPageHtml = await _getChannelPageHtml(channelId);
+    var channelTitle = channelPageHtml
+        .querySelector('meta[property="og:title"]')
+        .attributes['content'];
+    var channelImage = channelPageHtml
+        .querySelector('meta[property="og:image"]')
+        .attributes['content'];
+
+    return Channel(channelId, channelTitle, Uri.parse(channelImage));
+  }
+
+  /// Get a channel id from a username.
+  /// Might not work properly.
+  Future<String> getChannelId(String username) async {
+    if (!validateUsername(username)) {
+      throw ArgumentError.value(
+          username, 'username', 'Invalid YouTube username.');
+    }
+
+    var userPageHtml = await _getUserPageHtml(username);
+
+    var channelUrl = userPageHtml
+        .querySelector('meta[property="og:url"]')
+        .attributes['content'];
+
+    return channelUrl.replaceFirst('/channel/', '');
+  }
+
+  /// Returns all the videos uploaded by a channel up to [maxPages] count.
+  Future<List<Video>> getChannelUploads(String channelId,
+      [int maxPages = 5]) async {
+    if (!validateChannelId(channelId)) {
+      throw ArgumentError.value(
+          channelId, 'channelId', 'Invalid YouTube channel id.');
+    }
+
+    var playlistId = 'UU${channelId.replaceFirst('UC', '')}';
+    var playlist = await getPlaylist(playlistId, maxPages);
+
+    return playlist.videos;
+  }
+
+  Future<Document> _getChannelPageHtml(String channelId) async {
+    var url = 'https://www.youtube.com/channel/$channelId?hl=en';
+    var raw = (await client.get(url)).body;
+
+    return html.parse(raw);
+  }
+
+  Future<Document> _getUserPageHtml(String username) async {
+    var url = 'https://www.youtube.com/user/$username?hl=en';
+    var raw = (await client.get(url)).body;
+
+    return html.parse(raw);
+  }
+
+  /// Returns true if [username] is a valid Youtube username.
+  static bool validateUsername(String username) {
+    if (username.isNullOrWhiteSpace) {
+      return false;
+    }
+
+    if (username.length > 20) {
+      return false;
+    }
+
+    return !RegExp(r'[^0-9a-zA-Z]').hasMatch(username);
+  }
+
+  /// Parses a username from an url.
+  /// Returns null if the username is not found.
+  static String parseUsername(String url) {
+    if (url.isNullOrWhiteSpace) {
+      return null;
+    }
+
+    var regMatch = _usernameRegMatchExp.firstMatch(url)?.group(1);
+    if (!regMatch.isNullOrWhiteSpace && validateUsername(regMatch)) {
+      return regMatch;
+    }
+    return null;
+  }
+
+  /// Returns true if [channelId] is a valid Youtube channel id.
+  static bool validateChannelId(String channelId) {
+    if (channelId.isNullOrWhiteSpace) {
+      return false;
+    }
+
+    channelId = channelId.toLowerCase();
+
+    if (!channelId.startsWith('uc')) {
+      return false;
+    }
+
+    if (channelId.length != 24) {
+      return false;
+    }
+
+    return !RegExp(r'[^0-9a-zA-Z]').hasMatch(channelId);
+  }
+
+  /// Parses a channel id from an url.
+  /// Returns null if the username is not found.
+  static String parseChannelId(String url) {
+    if (url.isNullOrWhiteSpace) {
+      return null;
+    }
+
+    var regMatch = _idRegMatchExp.firstMatch(url)?.group(1);
+    if (!regMatch.isNullOrWhiteSpace && validateChannelId(regMatch)) {
+      return regMatch;
+    }
+    return null;
+  }
+}

lib/src/extensions/extensions.dart

@@ -0,0 +1,3 @@
+export 'channel_extension.dart';
+export 'helpers_extension.dart';
+export 'playlist_extension.dart';

lib/src/extensions/helpers_extension.dart

@@ -1,4 +1,4 @@
-import 'cipher/cipher_operations.dart';
+import '../cipher/cipher_operations.dart';
 
 /// Utility for Strings.
 extension StringUtility on String {

lib/src/extensions/playlist_extension.dart

@@ -1,9 +1,9 @@
 import 'dart:convert';
 
-import 'extensions.dart';
-import 'models/models.dart';
-import 'parser.dart' as parser;
-import 'youtube_explode_base.dart';
+import '../models/models.dart';
+import '../parser.dart' as parser;
+import '../youtube_explode_base.dart';
+import 'helpers_extension.dart';
 
 /// Playlist extension for YoutubeExplode
 extension PlaylistExtension on YoutubeExplode {
@@ -29,8 +29,7 @@ extension PlaylistExtension on YoutubeExplode {
   /// If the id is not valid an [ArgumentError] is thrown.
   Future<Playlist> getPlaylist(String playlistId, [int maxPages = 500]) async {
     if (!validatePlaylistId(playlistId)) {
-      throw ArgumentError.value(
-          playlistId, 'videoId', 'Invalid video id');
+      throw ArgumentError.value(playlistId, 'videoId', 'Invalid video id');
     }
 
     Map<String, dynamic> playlistJson;

lib/src/models/channel.dart

@@ -0,0 +1,14 @@
+/// Information about a YouTube channel.
+class Channel {
+  /// ID of this channel.
+  final String id;
+
+  /// Title of this channel.
+  final String title;
+
+  /// Logo image URL of this channel.
+  final Uri logoUrl;
+
+  /// Initializes an instance of [Channel]
+  Channel(this.id, this.title, this.logoUrl);
+}

lib/src/models/models.dart

@@ -2,6 +2,7 @@ library youtube_explode.models;
 
 export 'audio_encoding.dart';
 export 'audio_stream_info.dart';
+export 'channel.dart';
 export 'container.dart';
 export 'media_stream_info.dart';
 export 'media_stream_info_set.dart';

lib/src/youtube_explode_base.dart

@@ -2,13 +2,13 @@ import 'dart:convert';
 import 'dart:io';
 
 import 'package:html/dom.dart';
-import 'package:http/http.dart' as http;
 import 'package:html/parser.dart' as html;
+import 'package:http/http.dart' as http;
+
 import 'cipher/cipher.dart';
-import 'extensions.dart';
+import 'extensions/extensions.dart';
 import 'models/models.dart';
 import 'parser.dart' as parser;
-import 'playlist_extension.dart';
 
 /// YoutubeExplode entry class.
 class YoutubeExplode {
@@ -389,13 +389,33 @@ class YoutubeExplode {
     return null;
   }
 
+  /// Closes the youtube explode's http client.
+  void close() {
+    client.close();
+  }
+
+  /* Export the extension static members. */
+
   /// Parses a playlist [url] returning its id.
   /// If the [url] is a valid it is returned itself.
   static String parsePlaylistId(String url) =>
       PlaylistExtension.parsePlaylistId(url);
 
-  /// Closes the youtube explode's http client.
-  void close() {
-    client.close();
-  }
+  /// Returns true if [username] is a valid Youtube username.
+  static bool validateUsername(String username) =>
+      ChannelExtension.validateUsername(username);
+
+  /// Parses a username from an url.
+  /// Returns null if the username is not found.
+  static String parseUsername(String url) =>
+      ChannelExtension.parseUsername(url);
+
+  /// Returns true if [channelId] is a valid Youtube channel id.
+  static bool validateChannelId(String channelId) =>
+      ChannelExtension.validateChannelId(channelId);
+
+  /// Parses a channel id from an url.
+  /// Returns null if the username is not found.
+  static String parseChannelId(String url) =>
+      ChannelExtension.parseChannelId(url);
 }

lib/youtube_explode_dart.dart

@@ -1,5 +1,6 @@
 library youtube_explode;
 
+export 'src/extensions/extensions.dart'
+    hide StringUtility, ListDecipher, ListFirst; // Hide helper extensions.
 export 'src/models/models.dart';
-export 'src/playlist_extension.dart';
 export 'src/youtube_explode_base.dart';

pubspec.yaml

@@ -1,6 +1,6 @@
 name: youtube_explode_dart
 description: A port in dart of the youtube explode library. Support serveral API functions.
-version: 0.0.1
+version: 0.0.2
 homepage: https://github.com/Hexer10/youtube_explode_dart
 
 environment: