Formulating a plan

Before we jump into the code for the App component, let’s do a little up-front design so that we know what we’re building.

The following diagram shows all the components you’ve built and how App will connect them:

Figure 8.1 – The component hierarchy

Here’s how it’ll work:

1. When the user first loads the app, they will see a list of today’s appointments using the AppointmentsDayView component, which will have its appointment data populated by its container AppointmentsDayViewLoader component.
2. At the top of the screen, the user will see a button labeled Add customer and appointment. Clicking that button makes AppointmentsDayView disappear and CustomerForm appear.
3. When the form is filled out and the submit button is clicked, the user is shown AppointmentForm and can add a new appointment for that customer.
4. Once they’ve added the appointment, they’ll be taken...