xcoobee-sdk/src/xcoobee/api/UsersCache.js

The XcooBee SDK is a facility to abstract lower level calls and implement standard behaviors. The XcooBee team is providing this to improve the speed of implementation and show the best practices while interacting with XcooBee.

const UsersApi = require('./UsersApi');

/**
 * A cache for user information fetched using the `xcoobee/api/UserApi.user`
 * function.
 */
class UsersCache {

  /**
   * Constructs a new user cache with the specified configuration.
   *
   * @param {ApiAccessTokenCache} apiAccessTokenCache The API access token cache to
   *   use so that a new API access token is not needed on each call.
   */
  constructor(apiAccessTokenCache) {
    this._ = {
      apiAccessTokenCache,
      internalCache: {},
    };
  }

  /**
   * Fetches the user information for the specified API key/secret pair.
   *
   * @param {string} apiUrlRoot - The root of the API URL.
   * @param {string} apiKey - Your API key.
   * @param {string} apiSecret - Your API secret.
   * @param {boolean} [fresh=false] - Flag indicating whether to force fetching
   *   fresh user information instead of returning a cached version.
   *
   * @returns {Promise<Object>} An object with information about the user that
   *   corresponds with the specified API key/secret pair.
   *
   * @throws {XcooBeeError}
   */
  get(apiUrlRoot, apiKey, apiSecret, fresh) {
    const key = `${apiKey}:${apiSecret}`;

    if (fresh !== true && key in this._.internalCache) {
      const user = this._.internalCache[key];
      return Promise.resolve(user);
    }

    return this._.apiAccessTokenCache.get(apiUrlRoot, apiKey, apiSecret)
      .then((apiAccessToken) => {
        return UsersApi.getUser(apiUrlRoot, apiAccessToken)
          .then((user) => {
            this._.internalCache[key] = user;
            return user;
          })
          .catch(() => {
            // If unable to fetch the user, then it may be due to an old expired API access
            // token.
            // TODO: Only perform the following if we are sure the `err` here is due to an
            // invalid API access token.
            return this._.apiAccessTokenCache.get(apiUrlRoot, apiKey, apiSecret, true)
              .then((newApiAccessToken) => {
                return UsersApi.getUser(apiUrlRoot, newApiAccessToken)
                  .then((user) => {
                    this._.internalCache[key] = user;
                    return user;
                  });
              });
          });
      });
  }

}

module.exports = UsersCache;