Last updated October 22, 2018

You probably created a form with the intent of collecting user input and then doing something with that input. Using the submitForm() method of our form class we can access the validated, and sanitized, user input data and make use of it for our own needs. We might do things like save the collected data as configuration, update an entity, or use it as part of a search query.

In this tutorial we'll:

  • Demonstrate how to add a submitForm() method to a form controller class
  • Access the value(s) of form input elements via the $form_state object
  • Set a redirect after performing processing in a form submission handler
  • Look at alternative ways to affect the submission handling of a form like #submit callbacks

By the end of this tutorial you should know how to access the values of a submitted form, and how to write custom processing code that gets invoked when the form passes validation.