oauth1_init.dart

oauth1_init.dart

import 'package:oauth1/oauth1.dart' as oauth1;

const String FLICKR_API_URL_OAUTH_BASE="https://www.flickr.com/services/oauth";
const String FLICKR_API_URL_REQUEST_TOKEN ="$FLICKR_API_URL_OAUTH_BASE/request_token";
const String FLICKR_API_URL_AUTHORIZE="$FLICKR_API_URL_OAUTH_BASE/authorize";
const String FLICKR_API_URL_ACCESS_TOKEN="$FLICKR_API_URL_OAUTH_BASE/access_token";

class FlickrApiClient {
  
  final platform = new oauth1.Platform(
      FLICKR_API_URL_REQUEST_TOKEN,
      FLICKR_API_URL_AUTHORIZE,
      FLICKR_API_URL_ACCESS_TOKEN,
      oauth1.SignatureMethods.hmacSha1// signature method
  );

  final clientCredentials = new oauth1.ClientCredentials(FLICKR_API_KEY, FLICKR_API_SECRET);

  var _auth = new oauth1.Authorization(clientCredentials, platform);

  oauth1.Credentials _tempCredentials;
  // get temp token from flickr and return web url
  Future<String> getRequestTokenUrl() async {
    final response = await _auth.requestTemporaryCredentials('oob');
    _tempCredentials = response.credentials;
    return "${_auth.getResourceOwnerAuthorizationURI(_tempCredentials.token)}";
  }
  
  // get real token with pin code input from user
  Future<oauth1.Client> requestToken(String verifier) async {
    final response = await _auth.requestTokenCredentials(_tempCredentials, verifier);
    _tempCredentials = null;
    
    // save the token to local storage
    _saveToken(response.credentials);

    // this is the oauth1 client that we can use as httpClient to call other APIs that needed authentication.
    authClient = oauth1.Client(platform.signatureMethod, clientCredentials, response.credentials);
    return authClient;
  }
}