Managing Persistence with Callbacks

Building persistence

Let’s build our persistence solution. We will write quite a bit of code to start with, including a second Response model, but the benefits of this labor will be worth it. The second response will not be the same as the first because each response struct solves a different problem:

• One captures user responses.

• The other persists them to the database.

Using callbacks

We’ll manage persistence with callbacks, tweaking Mastery to take a function we’ll call when each new response is submitted. Here’s how the function will work:

• In some solutions, perhaps with an online practice quiz, if we don’t need to save responses, that function will do nothing.

• In others, that function will save responses to the database.