Adds support for TikTok client

lib/oauth2_client.dart

@@ -6,6 +6,7 @@ import 'package:oauth2_client/access_token_response.dart';
 import 'package:oauth2_client/authorization_response.dart';
 import 'package:oauth2_client/oauth2_response.dart';
 import 'package:oauth2_client/src/oauth2_utils.dart';
+import 'package:oauth2_client/tiktok_oauth2_client.dart';
 import 'package:random_string/random_string.dart';
 
 // import 'package:oauth2_client/src/web_auth.dart';
@@ -48,6 +49,7 @@ class OAuth2Client {
   String? revokeUrl;
   String authorizeUrl;
   String scopeSeparator;
+  late String clientKey;
 
   BaseWebAuth webAuthClient = createWebAuth();
   CredentialsLocation credentialsLocation;
@@ -70,7 +72,13 @@ class OAuth2Client {
       required this.redirectUri,
       required this.customUriScheme,
       this.credentialsLocation = CredentialsLocation.header,
-      this.scopeSeparator = ' '});
+      this.scopeSeparator = ' '}) {
+    clientKey = _getClientKey(this);
+  }
+
+  static String _getClientKey(OAuth2Client client) {
+    return client is TikTokOAuth2Client ? 'client_key' : 'client_id';
+  }
 
   /// Requests an Access Token to the OAuth2 endpoint using the Implicit grant flow (https://tools.ietf.org/html/rfc6749#page-31)
   Future<AccessTokenResponse> getTokenWithImplicitGrantFlow(
@@ -334,7 +342,7 @@ class OAuth2Client {
       Map<String, dynamic>? customParams}) {
     final params = <String, dynamic>{
       'response_type': responseType,
-      'client_id': clientId
+      clientKey: clientId
     };
 
     if (redirectUri != null && redirectUri.isNotEmpty) {
@@ -380,7 +388,7 @@ class OAuth2Client {
     //If a client secret has been specified, it will be sent in the "Authorization" header instead of a body parameter...
     if (clientSecret == null || clientSecret.isEmpty) {
       if (clientId != null && clientId.isNotEmpty) {
-        params['client_id'] = clientId;
+        params[clientKey] = clientId;
       }
     }
 */
@@ -413,7 +421,7 @@ class OAuth2Client {
     //If a client secret has been specified, it will be sent in the "Authorization" header instead of a body parameter...
     if (clientSecret == null) {
       if (clientId.isNotEmpty) {
-        params['client_id'] = clientId;
+        params[clientKey] = clientId;
       }
     } else {
       switch (credentialsLocation) {
@@ -424,7 +432,7 @@ class OAuth2Client {
           ));
           break;
         case CredentialsLocation.body:
-          params['client_id'] = clientId;
+          params[clientKey] = clientId;
           params['client_secret'] = clientSecret;
           break;
       }
@@ -486,7 +494,7 @@ class OAuth2Client {
     if (token != null) {
       var params = {'token': token, 'token_type_hint': tokenType};
 
-      if (clientId != null) params['client_id'] = clientId;
+      if (clientId != null) params[clientKey] = clientId;
       if (clientSecret != null) params['client_secret'] = clientSecret;
 
       http.Response response =

lib/tiktok_oauth2_client.dart

@@ -0,0 +1,95 @@
+import 'dart:convert';
+
+import 'package:dio/dio.dart';
+import 'package:http/http.dart' as http;
+import 'package:oauth2_client/access_token_response.dart';
+import 'package:oauth2_client/oauth2_client.dart';
+
+class TikTokOAuth2Client extends OAuth2Client {
+  TikTokOAuth2Client(
+      {required String redirectUri, required String customUriScheme})
+      : super(
+          authorizeUrl: 'https://www.tiktok.com/v2/auth/authorize',
+          tokenUrl: 'https://open.tiktokapis.com/v2/oauth/token/',
+          revokeUrl: 'https://open.tiktokapis.com/v2/oauth/revoke/',
+          scopeSeparator: ',',
+          credentialsLocation: CredentialsLocation.body,
+          redirectUri: redirectUri,
+          customUriScheme: customUriScheme,
+        );
+
+  @override
+  Future<AccessTokenResponse> requestAccessToken({
+    required String code,
+    required String clientId,
+    String? clientSecret,
+    String? codeVerifier,
+    List<String>? scopes,
+    Map<String, dynamic>? customParams,
+    Map<String, String>? customHeaders,
+    httpClient,
+  }) async {
+    final params = getTokenUrlParams(
+      code: code,
+      redirectUri: redirectUri,
+      codeVerifier: codeVerifier,
+      customParams: customParams,
+    );
+
+    final headers = {
+      ...?customHeaders,
+      ...{'Content-Type': 'application/x-www-form-urlencoded'}
+    };
+
+    var response = await _performAuthorizedRequest(
+      url: tokenUrl,
+      clientId: clientId,
+      clientSecret: clientSecret,
+      params: params,
+      headers: headers,
+      httpClient: httpClient,
+    );
+
+    return http2TokenResponse(response, requestedScopes: scopes);
+  }
+
+  Future<http.Response> _performAuthorizedRequest({
+    required String url,
+    required String clientId,
+    String? clientSecret,
+    Map? params,
+    Map<String, String>? headers,
+    http.Client? httpClient,
+  }) async {
+    final dio = Dio();
+
+    headers ??= {};
+    params ??= {};
+
+    //If a client secret has been specified, it will be sent in the "Authorization" header instead of a body parameter...
+    if (clientSecret == null) {
+      if (clientId.isNotEmpty) {
+        params[clientKey] = clientId;
+      }
+    } else {
+      switch (credentialsLocation) {
+        case CredentialsLocation.header:
+          headers.addAll(getAuthorizationHeader(
+            clientId: clientId,
+            clientSecret: clientSecret,
+          ));
+          break;
+        case CredentialsLocation.body:
+          params[clientKey] = clientId;
+          params['client_secret'] = clientSecret;
+          break;
+      }
+    }
+
+    var response = await dio.post<Map<String, dynamic>>(url,
+        data: params,
+        options: Options(headers: headers, responseType: ResponseType.json));
+
+    return http.Response(jsonEncode(response.data), response.statusCode ?? 0);
+  }
+}

pubspec.yaml

@@ -16,6 +16,7 @@ dependencies:
   http: ^1.1.0
   meta: ^1.12.0
   random_string: ^2.3.1
+  dio: ^5.8.0+1
 
 dev_dependencies:
   flutter_test: