Simple Login in Firebase Web API

Authentication and Authorization are the primary ways to maintain the integrity of web apps. In this post, we will see basic authentication i.e. Simple Login in Firebase Web API

Simple Login in Firebase Web API

Authentication and Authorization are the primary ways to maintain integrity.

We all know about the how-to’s of these in Web Apps. Today we will see basic authentication i.e. Simple Login in Firebase

As it is a Database-as-a-Service, it also supplies an authentication system which can be leveraged for basic needs application.

Edit:
Auth schemes in new Google Firebase:
time2hack.com/auth-schemes-in-google-firebase/

For quick view on what we are building here, the sweet demo and download links for this Contact Store App are:

Github Repo Demo

In the last post we had already discussed about the introduction of Firebase and setting up a quick application with Firebase. Let's equip our last app i.e. Contact Store Application with Authentication.

So before moving ahead, lets see how the data is stored in Firebase; as in last post we saw a sample data like this:

{
  "contacts" : {
    "-Jl4Y4ek1Gpb1dLW9R8o" : {
      "email" : "[email protected]",
      "location" : {
        "city" : "Gurgaon",
        "state" : "Haryana",
        "zip" : "122001"
      },
      "name" : "Pankaj Patel"
    },
    ...
  }
}

Some notes on Firebase Realtime DB

  • It is NoSQL based
  • Data is written as JSON
  • Every JSON Object represents a node in the DB Tree
  • A Node may or may not have child nodes
  • Firebase avoids arrays, because of possible key collision on concurrent access of DB Data
  • Arrays are replaced by Objects of key and value pairs
  • Keys in collection are generated by Firebase e.g. -Jl4Y4ek1Gpb1dLW9R8o

So if the DB has children till 5th level, and we are accessing any third level child; we will receive all the data which it possess along with all its children.


Hence, we need to plan the application and the DB structure accordingly. This planning will totally depend on the following two things:

  1. Primary Purpose
  2. Good to Have Features

For now, we are not planning to build any Contact Sharing in this Article, every user is having control on their data. This means that there is no intersection among the users.

So as per this plan we can create users as immediate child of DB and contacts will be the children of users. This structure will look like the following:

{
  "contactdb" :{
    "profiles" : {
      "1" : {
        "email" : "[email protected]",
        "location" : {
          "city" : "Gurgaon",
          "state" : "Haryana",
          "zip" : "122001"
        },
        "name" : "Pankaj Patel"
      }
    },
    "contacts" : {
      "1" : {
        "-Jl9cQXgm_6YkdC1xgCK" : {
          "name" : "Pankaj",
          "email" : "[email protected]",
          "location" : {
            "city" : "Gurgaon",
            "state" : "Haryana",
            "zip" : "122001"
          },
        },
      },
    }
  }
}

For this simple login, we need to enable Email and Password authentication scheme in our Firebase DB.


After that we need to setup the security rules for our DB. It is very critical and important to setup the security rules which works with the authentication scheme and DB structure.

As we have decided the DB structure, we would write the security rules as follows. It will have the combination of .read, .write, $variables, $validations and some session constants like auth.

{
  "rules": {
    "profiles": {
      "$uid": {
        // grants write access to the owner of this user account
        // whose uid must exactly match the key ($uid)
        ".write": "auth !== null && auth.uid === $uid",

        // grants read access to any user who is logged in
        // with an email and password
        ".read": "auth !== null && auth.provider === 'password'"
      }
    },
    "conatcts":{
      "$uid": {
        // grants write access to the owner of this user account
        // whose uid must exactly match the key ($uid)
        ".write": "auth !== null && auth.uid === $uid",

        // grants read access to any user who is logged in
        // with an email and password
        ".read": "auth !== null && auth.provider === 'password'"
      }
    }
  }
}

Short notes on Firebase Security Rules

  • All the rules will be listed under a global object.
  • rules will be the only child in Global Object
  • .read and .write are used to set the readability and write-ability of any object
  • .read and .write can be set to true OR false
  • .validate can check what type of data can be written
  • .validate can also be used to block the writes
  • .validate can’t check for deletions
  • auth is a global variable holding the provider and uid information of user
  • provider can be password, facebook, github etc.
  • uid is auth scheme based i.e. simplelogin:1, facebook:2, github:3 etc.

There’s more that we can do with the firebase security rules. You can get full info on firebase security rules here.


The profiles and contacts are our data storage areas, and with .read and .write we can specify who should be allowed to read and write data at particular object.

Below the profiles or contacts object, we have specified $uid variable to indicate a user logging in, where auth will hold the basic authentication info like the userId and provider. In our Simple Login scheme, provider is password.

For login, we need to create users. We can create a new user by createUserWithEmailAndPassword method on our DB reference. This method can be used in following way:

const data = {
  // get the email from the Form
  email: $('#registerEmail').val(),
  // get the password from the Form
  password : $('#registerPassword').val()
};
firebase
  .auth()
  .createUserWithEmailAndPassword(data.email, data.password)
  .then((user) => {
    console.log(
      "Successfully created user account with uid:",
      user.uid
    );
  })
  .catch((error) => {
    console.log("Error creating user:", error);
  });

In createUserWithEmailAndPassword, we accomplished following things sequentially:

  • Created a user with supplied email and password
  • Logged the user in. This is explained further.
  • Saved the extra info in profiles collection in out DB

Now to login with Simple Login scheme in Firebase, authWithPassword method can be used in DB Reference.

const data = {
  email: $('#loginEmail').val(),
  password: $('#loginPassword').val()
};

let auth = null;

firebase
  .auth()
  .signInWithEmailAndPassword(data.email, data.password)
  .then((user) => {
    console.log("Authenticated successfully with payload:", user);
    auth = user;
  })
  .catch((error) => {
    console.log("Login Failed!", error);
  });

Now, we have a successful registration and login, we can operate the DB as per our desired data needs.

Here’s the full code to the sample Contacts Store app created with the Simple Login in Firebase. In following code, there is some code to make the UI work like a real application.


To sign-out/logout the user, simply call the signOut auth instance. For example: firebase.auth().signOut().

This returns a promise which can be used to handle other tasks like cleaning up user state and data from app and browser local/session storage.


Demo and download links for this Contact Store App:

Github Repo Demo

Here is the HTML for our final Contact Store Application:

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <link rel="shortcut icon" href="https://time2hack.com/favicon.png" type="image/png">
  <link rel="icon" href="https://time2hack.com/favicon.png" type="image/png">
  <title>Time to Hack: Simple Login with Firebase Web API</title>
  <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.1/css/bootstrap.min.css" integrity="sha384-WskhaSGFgHYWDcbwN70/dfYBj47jz9qbsMId/iRN3ewGhXQFZCSftd1LZCfmhktB" crossorigin="anonymous">
  <link rel="stylesheet" href="//maxcdn.bootstrapcdn.com/font-awesome/4.3.0/css/font-awesome.min.css">
  <link rel="stylesheet" href="./style.css">
</head>
<body class="auth-false">
  <div class="container">
    <header class="clearfix">
      <h1>Contact Store Application</h1>
      <div class="userAuth unauthenticated pull-right">
        <button type="button" class="btn btn-primary" data-toggle="modal" data-target="#registerModal">Register</button>
        <button type="button" class="btn btn-success" data-toggle="modal" data-target="#loginModal">Login</button>
      </div>
      <div class="userAuth authenticated pull-right">
        <span class="user-info">
          <img src="./user.svg" alt="User" class="rounded-circle">
        </span>
        <button type="button" class="btn btn-success" id="logout">Logout</button>
      </div>
    </header>
    <hr/>
    <main class="authenticated">
      <center>
        <button type="button" class="btn btn-primary" data-toggle="modal" data-target="#addContactModal">Add Contact</button>
      </center>
      <div id="contacts"></div>
    </main>
  </div>
  <div class="row">
    <div class="col-md-6">
      <div><iframe src="//time2hack.com/ads.html" frameborder=0 width="100%" class="embed-responsive-item" align="center"></iframe></div>
    </div>
    <div class="col-md-6">
      <div><iframe src="//time2hack.com/ads.html" frameborder=0 width="100%" class="embed-responsive-item" align="center"></iframe></div>
    </div>
  </div>
  <div class="modal fade" id="registerModal" tabindex="-1" role="dialog" aria-labelledby="Register" aria-hidden="true">
    <div class="modal-dialog">
      <div class="modal-content">
        <form id="registerForm" method="POST">
          <div class="modal-header">
            <h4 class="modal-title" id="registerModalLabel">Register</h4>
            <button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">&times;</span></button>
          </div>
          <div class="modal-body">
            <div class="form-group">
              <label for="recipient-name" class="control-label">First Name:</label>
              <input type="text" class="form-control" id="registerFirstName">
            </div>
            <div class="form-group">
              <label for="recipient-name" class="control-label">Last Name:</label>
              <input type="text" class="form-control" id="registerLastName">
            </div>
            <div class="form-group">
              <label for="recipient-name" class="control-label">Email:</label>
              <input type="text" class="form-control" id="registerEmail">
            </div>
            <div class="form-group">
              <label for="message-text" class="control-label">Password:</label>
              <input type="password" class="form-control" id="registerPassword">
            </div>
            <div class="form-group">
              <label for="message-text" class="control-label">Confirm Password:</label>
              <input type="password" class="form-control" id="registerConfirmPassword">
            </div>
          </div>
          <div class="modal-footer">
            <button type="button" class="btn btn-default" data-dismiss="modal">Close</button>
            <button type="submit" class="btn btn-primary" id="doRegister">Register</button>
          </div>
        </form>
      </div>
    </div>
  </div>
  <div class="modal fade" id="loginModal" tabindex="-1" role="dialog" aria-labelledby="Login" aria-hidden="true">
    <div class="modal-dialog">
      <div class="modal-content">
        <form id="loginForm" method="POST">
          <div class="modal-header">
            <h4 class="modal-title" id="loginModalLabel">Login</h4>
            <button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">&times;</span></button>
          </div>
          <div class="modal-body">
            <div class="form-group">
              <label for="recipient-name" class="control-label">Email:</label>
              <input type="text" class="form-control" id="loginEmail">
            </div>
            <div class="form-group">
              <label for="message-text" class="control-label">Password:</label>
              <input type="password" class="form-control" id="loginPassword">
            </div>
          </div>
          <div class="modal-footer">
            <button type="button" class="btn btn-default" data-dismiss="modal">Close</button>
            <button type="submit" class="btn btn-primary" id="doLogin">Login</button>
          </div>
        </form>
      </div>
    </div>
  </div>
  <div class="modal fade" id="addContactModal" tabindex="-1" role="dialog" aria-labelledby="Add Contact" aria-hidden="true">
    <div class="modal-dialog">
      <div class="modal-content">
        <form method="POST" id="contactForm" name="contactForm">
          <div class="modal-header">
            <h4 class="modal-title" id="addContactModalLabel">Add Contact</h4>
            <button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">&times;</span></button>
          </div>
          <div class="modal-body">
            <div class="form-group">
              <label for="name">Name</label>
              <input type="text" class="form-control" id="name" required placeholder="Enter name">
            </div>
            <div class="form-group">
              <label for="email">Email</label>
              <input type="email" class="form-control" id="email" required placeholder="Enter Email">
            </div>
            <h3>Location</h3>
            <div class="form-group">
              <label for="city">City</label>
              <input type="text" class="form-control" id="city" placeholder="Enter City">
            </div>
            <div class="form-group">
              <label for="email">State</label>
              <input type="text" class="form-control" id="state" placeholder="Enter State">
            </div>
            <div class="form-group">
              <label for="zip">Zip</label>
              <input type="text" class="form-control" id="zip" placeholder="Enter Zip Code">
            </div>
          </div>
          <div class="modal-footer">
            <button type="button" class="btn btn-default" data-dismiss="modal">Close</button>
            <button type="submit" class="btn btn-primary addValue">Submit</button>
          </div>
        </form>
      </div>
    </div>
  </div>
  <div class="modal fade" id="messageModal" tabindex="-1" role="dialog" aria-labelledby="Message" aria-hidden="true">
    <div class="modal-dialog">
      <div class="modal-content">
        <div class="modal-header">
          <h4 class="modal-title" id="messageModalLabel">Message</h4>
          <button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">&times;</span></button>
        </div>
        <div class="modal-footer">
          <div class="pre-auth">
            <button type="button" class="btn btn-default pull-left" data-dismiss="modal">Close</button>
            <span class="">
              <button type="submit" class="btn btn-primary" data-dismiss="modal" data-toggle="modal" data-target="#registerModal">Register</button>
              <button type="submit" class="btn btn-success" data-dismiss="modal" data-toggle="modal" data-target="#loginModal">Login</button>
            </span>
          </div>
          <div class="post-auth"></div>
        </div>
      </div>
    </div>
  </div>

  <script src="https://code.jquery.com/jquery-3.3.1.slim.min.js" integrity="sha384-q8i/X+965DzO0rT7abK41JStQIAqVgRVzpbzo5smXKp4YfRvH+8abtTE1Pi6jizo" crossorigin="anonymous"></script>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.3/umd/popper.min.js" integrity="sha384-ZMP7rVo3mIykV+2+9J3UJ46jBk0WLaUAdn689aCwoqbBJiSnjAK/l8WvCWPIPm49" crossorigin="anonymous"></script>
  <script src="https://stackpath.bootstrapcdn.com/bootstrap/4.1.1/js/bootstrap.min.js" integrity="sha384-smHYKdLADwkXOn1EmN1qk/HfnUcbVRZyYmZ4qpPea6sjB/pTJ0euyQp0Mk8ck+5T" crossorigin="anonymous"></script>
  <script src="https://www.gstatic.com/firebasejs/4.3.1/firebase.js"></script>
  <!-- Contacts Store JavaScript -->
  <script src="./script.js"></script>
</body>
</html>

And the JavaScript for the app:

// file: script.js
$(document).ready(() => {
  //initialize the firebase app
  const config = {
    apiKey: "AIzaSyCKNcULQZxFMYioXei32XNWQVoeutz4XDA",
    authDomain: "contact-book-new.firebaseapp.com",
    databaseURL: "https://contact-book-new.firebaseio.com",
    projectId: "contact-book-new",
    storageBucket: "contact-book-new.appspot.com",
    messagingSenderId: "473268388365"
  };
  firebase.initializeApp(config);

  //create firebase references
  const Auth = firebase.auth(); 
  const dbRef = firebase.database();
  const contactsRef = dbRef.ref('contacts')
  const usersRef = dbRef.ref('users')
  let auth = null;

  //Register
  $('#registerForm').on('submit', (e) => {
    e.preventDefault();
    $('#registerModal').modal('hide');
    $('#messageModalLabel').html(spanText('<i class="fa fa-cog fa-spin"></i>', ['center', 'info']));
    $('#messageModal').modal('show');
    const data = {
      email: $('#registerEmail').val(), //get the email from Form
      firstName: $('#registerFirstName').val(), // get firstName
      lastName: $('#registerLastName').val(), // get lastName
    };
    const passwords = {
      password : $('#registerPassword').val(), //get the pass from Form
      cPassword : $('#registerConfirmPassword').val(), //get the confirmPass from Form
    }
    if (data.email && passwords.password && passwords.cPassword) {
      if (passwords.password == passwords.cPassword) {
        //create the user
        
        firebase.auth()
          .createUserWithEmailAndPassword(data.email, passwords.password)
          .then((user) => user.updateProfile({
              displayName: `${data.firstName} ${data.lastName}`
          }))
          .then((user) => {
            //now user is needed to be logged in to save data
            auth = user;
            //now saving the profile data
            usersRef
              .child(user.uid)
              .set(data)
              .then(() => console.log("User Information Saved:", user.uid))

            $('#messageModalLabel').html(spanText('Success!', ['center', 'success']))
            $('#messageModal').modal('hide');
          })
          .catch((error) => {
            console.log("Error creating user:", error);
            $('#messageModalLabel').html(spanText('ERROR: '+error.code, ['danger']))
          });
      } else {
        //password and confirm password didn't match
        $('#messageModalLabel').html(spanText("ERROR: Passwords didn't match", ['danger']))
      }
    }  
  });

  //Login
  $('#loginForm').on('submit', (e) => {
    e.preventDefault();
    $('#loginModal').modal('hide');
    $('#messageModalLabel').html(spanText('<i class="fa fa-cog fa-spin"></i>', ['center', 'info']));
    $('#messageModal').modal('show');

    if ($('#loginEmail').val() && $('#loginPassword').val()) {
      //login the user
      const data = {
        email: $('#loginEmail').val(),
        password: $('#loginPassword').val()
      };
      firebase.auth().signInWithEmailAndPassword(data.email, data.password)
        .then((authData) => {
          auth = authData;
          $('#messageModalLabel').html(spanText('Success!', ['center', 'success']))
          $('#messageModal').modal('hide');
        })
        .catch((error) => {
          console.log("Login Failed!", error);
          $('#messageModalLabel').html(spanText('ERROR: '+error.code, ['danger']))
        });
    }
  });

  $('#logout').on('click', (e) => {
    e.preventDefault();
    firebase.auth().signOut()
  });

  //save contact
  $('#contactForm').on('submit', (event) => {
    event.preventDefault();
    if (!auth) {
      //inform user to login
      alert('Please login')
      return;
    }
    
    if ($('#name').val() || $('#email').val()) {
      contactsRef.child(auth.uid)
        .push({
          name: $('#name').val(),
          email: $('#email').val(),
          location: {
            city: $('#city').val(),
            state: $('#state').val(),
            zip: $('#zip').val()
          }
        })
        document.contactForm.reset();
    } else {
      alert('Please fill at-lease name or email!');
    }
  });

  firebase.auth().onAuthStateChanged((user) => {
    if (user) {
      auth = user;
      $('body').removeClass('auth-false').addClass('auth-true');
      usersRef.child(user.uid).once('value').then((data) => {
        const info = data.val();
        if (user.photoUrl)  {
          $('.user-info img').show();
          $('.user-info img').attr('src', user.photoUrl);
          $('.user-info .user-name').hide();
        } else if (user.displayName)  {
          $('.user-info img').hide();
          $('.user-info').append('<span class="user-name">'+user.displayName+'</span>');
        } else if (info.firstName)  {
          $('.user-info img').hide();
          $('.user-info').append('<span class="user-name">'+info.firstName+'</span>');
        }
      });
      contactsRef.child(user.uid).on('child_added', onChildAdd);
    } else {
      // No user is signed in.
      $('body').removeClass('auth-true').addClass('auth-false');
      auth && contactsRef.child(auth.uid).off('child_added', onChildAdd);
      $('#contacts').html('');
      auth = null;
    }
  });
});

const onChildAdd = (snap) => {
  $('#contacts').append(contactHtmlFromObject(snap.key, snap.val()));
}

//prepare contact object's HTML
const contactHtmlFromObject = (key, contact) => `
  <div class="card contact" style="width: 18rem;" id="${key}">
    <div class="card-body">
      <h5 class="card-title">${contact.name}</h5>
      <h6 class="card-subtitle mb-2 text-muted">${contact.email}</h6>
      <p class="card-text" title="${contact.location.zip}">
        ${contact.location.city}, ${contact.location.state}
      </p>
    </div>
  </div>`;

const spanText = (textStr, textClasses) => {
  const classNames = textClasses.map(c => `text-${c}`).join(' ');
  return `<span class="${classNames}">${textStr}</span>`;
}

Github Repo Demo


Let me know through comments 💬 or on Twitter at @patel_pankaj_ and/or @time2hack

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