Token Refresh Link

Purpose

An Apollo Link that performs renew expired JWT (access tokens)

Installation

npm install apollo-link-token-refresh --save

Usage

Token Refresh Link is non-terminating link, which means that this link shouldn't be the last link in the composed chain.

import { TokenRefreshLink } from "apollo-link-token-refresh";

const link = new TokenRefreshLink({
  accessTokenField: 'accessToken',
  isTokenValidOrUndefined: () => boolean,
  fetchAccessToken: () => Promise<Response>,
  handleFetch: (accessToken: string) => void
});

Options

Token Refresh Link takes an object with four options on it to customize the behavior of the link

name	value	default	required	explanation
accessTokenField	string	'access_token'		This is a name of access token field in response
isTokenValidOrUndefined	(...args: any[]) => boolean		✓	Indicates the current state of access token expiration. If token not yet expired or user doesn't have a token (guest) true should be returned
fetchAccessToken	(...args: any[]) => Promise		✓	Function covers fetch call with request fresh access token
handleFetch	(accessToken: string) => void		✓	Callback which receives a fresh token from Response. From here we can save token to the storage

Example

import { TokenRefreshLink } from 'apollo-link-token-refresh';

link: ApolloLink.from([
  new TokenRefreshLink({
    isTokenValidOrUndefined: () => !isTokenExpired() || typeof getAccessToken() !== 'string'
    fetchAccessToken: () => {
      return fetch(getEndpoint('getAccessTokenPath'), {
        method: 'GET',
        headers: {
          Authorization: `Bearer ${getAccessToken()}`,
          'refresh-token': getRefreshToken()
        }
      });
    }
    handleFetch: accessToken => {
      const accessTokenDecrypted = jwtDecode(accessToken);
      setAccessToken(accessToken);
      setExpiresIn(parseExp(accessTokenDecrypted.exp).toString());
    }
  }),
  errorLink,
  requestLink,
  ...
])

Context

The Token Refresh Link does not use the context for anything