react-check-auth

react-check-auth is a tiny react component that helps you make auth checks declarative in your react or react-native app.

This component uses React 16's new context API and is just ~100 LOC. It can also serve as a boilerplate for getting familiar with using the context API to pass information from a parent component to arbitrarily deep child components.

Motivation

In a typical app UI, depending on whether the user logs in, components in the application display different information.

For example, a "welcome user" label or a "login button" on a header. Or using this information with routing, /home should redirect to /login if the user is not logged in, and /login should redirect to /home if the user is logged in.

Before react-check-auth

1. On load, your app must make a request to some kind of a /verifyUser or a /fetchUser endpoint to check if the existing persisted token/cookie is available and valid.
2. You need to store that information in app state and pass it as a prop all through your component tree just so that that child components can access it or use redux to store the state and connect() the consuming component.

After react-check-auth

1. You specify the authUrl endpoint as a prop to a wrapper component called <AuthProvider.
2. You access logged-in information by wrapping your react component/element in <AuthConsumer> that has the latest props.

You don't need to make an API request, or pass props around, or manage state/reducers/connections in your app.

Example

1) Add AuthProvider

Wrap your react app in a AuthProvider component that has an endpoint to fetch basic user information. This works because if the user had logged in, a cookie would already be present. For using authorization headers, check the docs after the examples.

import React from "react";
import ReactDOM from "react-dom";

import {AuthProvider} from "react-check-auth";
import {Header, Main} from "./components";

const App = () => (
  <AuthProvider authUrl={'https://website.com/get/userInfo'}>
    <div>
      // The rest of your react app goes here
      <Header />
      <Main />
    </div>
  </AuthProvider>
);

ReactDOM.render(<App />, document.getElementById("root"));

2) Show a "welcome user" or a Login button

Now, in any arbitrary component, like a Header, you can check if the user is currently logged in. Typically you would use this for either showing a "welcome" label or a login button.

  import {AuthConsumer} from 'react-check-auth';

  const Header = () => (
    <div>      
      // Use the AuthConsumer component to check 
      // if userInfo is available
      <AuthConsumer> 
        {({userInfo, isLoading, error}) => ( 
          userInfo ?
            (<span>Hi {userInfo.username}</span>) :
            (<a href="/login">Login</a>)
        )}
       </AuthConsumer>
    </div>
  );

3) Redirect not-logged in users to /login

You can mix and match react-check-auth with other declarative components like routing:

  import {AuthConsumer} from 'react-check-auth';

  const Main = () => (
    <Router>
      <Route path='/home' component={Home} />
      <Route path ='/login' component={Login} />
    </Router>
   );
   
   const Home = () => {
     return (
       <AuthConsumer>
         {({userInfo}) => {

           // Redirect the user to login if they are not logged in
           if (!userInfo) {
              return (<Redirect to='/login' />);
           } 
           
           // Otherwise render the normal component
           else {
             return (<div>Welcome Home!</div>);
           }
         }}
       </AuthConsumer>
     );
   }
);

Usage guide

I. Backend requirements

These are the backend requirements that are assumed by react-check-auth.

1) API endpoint to return user information

An API request to fetch user information. It should take a cookie, or a header or a body for current session information.

For example:

GET https://my-backend.com/api/user
Content-Type: application/json
Cookie: <...>
Authorization: Bearer <...>

2) Success or logged-in response

If the user is logged in, the API should return a 200 status code with a JSON object.

For example:

{
  "username": "iamuser",
  "id": 123
}

3) Not logged-in response

If the user is not logged-in, the API should return a non 200 status code:

For example:

Status: 403

II. Installation

$ npm install --save react-check-auth

III. Set up AuthProvider

The AuthProvider component should be at the top of the component tree so that any other component in the app can consume the userInfo information.

The AuthProvider takes a required prop called authUrl and an optional prop called reqOptions.

<AuthProvider authUrl="https://my-backend.com/api/user" reqOptions={requestOptionsObject} />

authUrl :: String

Should be a valid HTTP endpoint. Can be an HTTP endpoint of any method.

reqOptions :: Object || Function

Should be or return a valid fetch options object as per https://github.github.io/fetch/#options.

Note: This is an optional prop that does not need to be specified if your authUrl endpoint is a GET endpoint that accepts cookies.

Default value that ensures cookies get sent to a GET endpoint:

{ 
  "method": "GET",
  "credentials": "include",
  "headers": {
    "Content-Type": "application/json"
  },  
}

Example 1: Use a GET endpoint with cookies

  import React from 'react';
  import {AuthProvider} from 'react-check-auth';

  const authUrl = "https://my-backend.com/verifyAuth";
  
  const App = () => (
    <AuthProvider authUrl={authUrl}>
      // The rest of your app goes here
    </AuthProvider>
  );

Example 2: Use a GET endpoint with a header

  import React from 'react';
  import {AuthProvider} from 'react-check-auth';

  const authUrl = "https://my-backend.com/verifyAuth";
  const reqOptions = { 
    'method': 'GET',
    'headers': {
      'Content-Type': 'application/json',
      'Authorization' : 'Bearer ' + window.localStorage.myAuthToken
    },  
  }; 
  
  const App = () => (
    <AuthProvider authUrl={authUrl} reqOptions={reqOptions}>
      // The rest of your app goes here
    </AuthProvider>
  );

IV. Consuming auth state with <AuthConsumer>

Any react component or element can be wrapped with an <AuthConsumer> to consume the latest contextValue. You must write your react code inside a function that accepts the latest contextValue. Whenver the contextValue is updated then the AuthComponent is automatically re-rendered.

For example,

<AuthConsumer>
  {(props) => {
    
    props.userInfo = {..}        // <request-object> returned by the API
    props.isLoading = true/false // if the API has not returned yet
    props.error = {..}           // <error-object> if the API returned a non-200 or the API call failed
  }}
</AuthConsumer>

props.userInfo :: JSON

If the API call returned a 200 meaning that the current session is valid, userInfo contains as returned by the API.

If the API call returned a non-200 meaning that the current session is absent or invalid, userInfo is set to null.

props.isLoading :: Boolean

If the API call has not returned yet, isLoading: true. If the API call has not been made yet, or has completed then isLoading: false.

props.error :: JSON

If the API call returned a non-200 or there was an error in making the API call itself, error contains the parsed JSON value.

V. Refresh state (eg: logout)

If you implement a logout action in your app, the auth state needs to be updated. All you need to do is call the refreshAuth() function available as an argument in the renderProp function of the AuthConsumer component.

For example:

<AuthConsumer>
  {(refreshAuth) => (
    <button onClick={{
      this.logout() // This is a promise that calls a logout API
        .then(
          () => refreshAuth()
        );
    }}>
      Logout
    </button>
</AuthConsumer>  

This will re-run the call to authUrl and update all the child components accordingly.

VI. Using with React Native

Usage with React Native is exactly the same as with React. However you would typically use a Authorization header instead of cookies. Here's a quick example:

import { AuthProvider, AuthConsumer } from 'react-vksci123';

export default class App extends Component<Props> {
  render() {
    const sessionToken = AsyncStorage.getItem("@mytokenkey");
    const reqOptions = {
      "method": "GET",
      "headers": sessionToken ? { "Authorization" : `Bearer ${sessionToken}` } : {}
    }
    return (
      <AuthProvider
        authUrl={`https://my-backend.com/api/user`}
        reqOptions={reqOptions}
      >
        <View style={styles.container}>
          <Text style={styles.welcome}>
            Welcome to React Native!
          </Text>
          <AuthConsumer>
            {({isLoading, userInfo, error}) => {
              if (isLoading) {
                return (<ActivityIndicator />);
              }
              if (error) {
                return (<Text> Unexpected </Text>);
              }
              if (!userInfo) {
                return (<LoginComponent />);
              }
              return (<HomeComponent />);
            }}
          </AuthConsumer>
        </View>
      </AuthProvider>
    );
  }
}

Plug-n-play with existing auth providers

All Auth backend providers provide an endpoint to verify a "session" and fetch user information. This component was motivated from creating documentation for integrating Hasura's auth backend into a react app with minimum boilerplate. That said this package is meant to be used with any auth provider, including your own.

Hasura

Hasura's Auth API can be integrated with this module with a simple auth get endpoint and can also be used to redirect the user to Hasura's Auth UI Kit in case the user is not logged in.

  // replace CLUSTER_NAME with your Hasura cluster name.
  const authEndpoint = 'https://auth.CLUSTER_NAME.hasura-app.io/v1/user/info';

  // pass the above reqObject to CheckAuth
  <AuthProvider authUrl={authEndpoint}>
    <AuthConsumer>
    { ({ isLoading, userInfo, error }) => { 
      // your implementation here
    } }
    </AuthConsumer>
  </AuthProvider>

Read the docs here.

Firebase

CheckAuth can be integrated with Firebase APIs.

  // replace API_KEY with your Firebase API Key and ID_TOKEN appropriately.
  const authUrl = 'https://www.googleapis.com/identitytoolkit/v3/relyingparty/getAccountInfo?key=[API_KEY]';
  const reqObject = { 'method': 'POST', 'payload': {'idToken': '[ID_TOKEN]'}, 'headers': {'content-type': 'application/json'}};

  // pass the above reqObject to CheckAuth
  <AuthProvider authUrl={authUrl} reqObject={reqObject}>
    <AuthConsumer>
    { ({ isLoading, userInfo, error }) => { 
      // your implementation here
    } }
    </AuthConsumer>
  </AuthProvider>

Custom Provider

CheckAuth can be integrated with any custom authentication provider APIs.

Lets assume we have an endpoint on the backend /api/check_token which reads a header x-access-token from the request and provides with the associated user information

  const authEndpoint = 'http://localhost:8080/api/check_token';
  const reqOptions = { 
    'method': 'GET',
    'headers': {
      'Content-Type': 'application/json',
      'x-access-token': 'jwt_token'
    }
  };

  <AuthProvider authUrl = { authEndpoint } reqOptions={ reqOptions }>
    <AuthConsumer>
      { ( { isLoading, userInfo, error, refreshAuth }) => {
        if ( !userInfo ) {
          return (
            <span>Please login</span>
          );
        }
        return (
          <span>Hello { userInfo ? userInfo.username.name : '' }</span>
        );
      }}
    </AuthConsumer>
  </AuthProvider>

It will render as <span>Please login</span> if the user's token is invalid and if the token is a valid one it will render Hello username

How it works

1. The AuthProvider component uses the authUrl and reqOptions information given to it to make an API call
2. While the API call is being made, it sets the context value to have isLoading to true.

{
  "userInfo": null,
  "isLoading": true,
  "error": null
}

3. Once the API call returns, in the context value isLoading is set to `false' and:
4. Once the API call returns, if the user is logged in, the AuthProvider sets the context to userInfo: <response-object>

{
  "userInfo": <response-object>,
  "isLoading": false,
  "error": null
}

5. If the user is not logged in, in the context value, userInfo is set to null and error is set to the error response sent by the API, if the error is in JSON.

{
  "userInfo": null,
  "isLoading": false,
  "error": <error-response>
}

6. If the API call fails for some other reason, error contains the information

{
  "userInfo": null,
  "isLoading": false,
  "error": <error-response>
}

7. Whenever the contextValue is updated, any component that is wrapped with AuthConsumer will be re-rendered with the contextValue passed to it as an argument in the renderProp function:

<AuthConsumer>
  { ({userInfo, isLoading, error}) => {
     return (...);
  }}
<AuthConsumer>

Contributing

Clone repo

git clone https://github.com/hasura/react-check-auth.git

Install dependencies

npm install or yarn install

Start development server

npm start or yarn start

Runs the demo app in development mode.

Open http://localhost:3000 to view it in the browser.

Source code

The source code for the react components are located inside src/lib.

Demo app

A demo-app is located inside src/demo directory, which you can use to test your library while developing.

Testing

npm run test or yarn run test

Build library

npm run build or yarn run build

Produces production version of library under the build folder.

Maintainers

This project has come out of the work at hasura.io. Current maintainers @Praveen, @Karthik, @Rishi.