In the Rails 6 course, our forms currently let in bad data. Yikes! It’s high time we ensure the integrity of our application data and give notice to our users when things go right as well as when things go wrong. 💥

To prevent bad (invalid) data from making its way into the database, we add a variety of model validations and explore how they work in detail.

Now we’re ready to handle and display any validation errors when submitting form data. You’ll come away with a solid strategy for ensuring the integrity of your application’s data while providing actionable feedback in the user interface.

While on the topic of user feedback, we have a few cases where we need to flash a stylish message up on the page. It’s common for web apps to flash messages between requests, and so Rails makes it easy.

Enjoy!