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Build a login form with HTML

In this section, we create a custom login form with email/username and password that includes:

#Example: custom login form

You can clone the example login form on CodePen(opens new window) and make edits, or follow along below.

The example form has the Userfront Core JS library added to the document, as described in the next section.

#Add the Userfront Core JS library

You can add the Userfront Core JS library by CDN or using npm.

You only need to do one of these.

#CDN

#NPM

Then import the library into your file(s)

#Set up the form

Create your login form with the elements you want to use.

In this case, we've added:

  • email-or-username - the user's email address or username
  • password - required for login with password

#Pass form data to Userfront.login()

The login() method allows you to pass in data to log in a user.

Our JavaScript needs to pass our form data into this method.

Userfront then does the following:

  1. Verifies the user's credentials
  2. Adds the user's access token as a cookie named access.demo1234
  3. Redirects the page to the After-login path

#Example JavaScript

In the example code here, we do the following:

  1. Reference all the elements on the page
  2. Define a custom formLogin() method that calls Userfront.login() with the form values
  3. Add an event listener to call formLogin() when the form is submitted

#Email or username field

For login, you can use the emailOrUsername field, which will accept both email and username.

If you want email only, or username only, you can use the email or username attributes instead of emailOrUsername.

#Error handling

Whenever the Userfront.login() method fails, we can catch its error in the promise chain.

This error contains a message property with what went wrong.

In this example, we use the setAlert() method to display the error message inside of our alert element.

#Single sign-on

To configure Single sign-on (SSO), first add the provider you want to use in the Userfront dashboard in the SSO tab.

In this example, we add an event listener to call Userfront.login() with "google" as the login method whenever the Google button is clicked. You can style the button however you like, or initiate the login programmatically.

You can find more provider options like GitHub, LinkedIn, and Facebook in the docs for login().

#Login after redirect

Once the browser is redirected back to your login page after SSO approval, your application should call

Userfront.login({ method: "link" }).

You can set up your JS to call this method automatically by checking whether the URL contains the token and uuid parameters.

If your original SSO signup call contained a redirect parameter, it will be included in the URL and followed automatically.