Module 8: Putting it All Together
Order flows are where attractive demos become real products. As soon as delivery is involved, the app needs to collect an address, remember it sensibly, and enforce the business rules that determine whether an order can actually be placed.
This lesson adds that missing layer. The address form itself is intentionally modest, which is fine. The important thing is not to over-design the input screen. It is to make the data collection predictable and easy to validate.
The older implementation uses explicit property binding code, and the video notes that newer APIs such as Instant UI would now be a more natural fit for some of this work. That is still the right modern guidance. If you are building a similar form today, use the current property-binding and form-generation tools where they simplify the code instead of re-implementing boilerplate by hand.
The validation logic is where this lesson becomes more than form wiring. Delivery range, minimum order value, and delivery fee are business rules, not presentation details. That means the UI should surface them clearly, but the application model should own them. Once those rules live in the right place, the rest of the checkout experience becomes more trustworthy because the app is enforcing real constraints instead of merely collecting text fields.
Location-aware validation is especially useful here. If the restaurant only serves users within a certain radius, the app should check that early enough to save frustration. The exact implementation can vary, but the principle is clear: validate the order against the real-world service boundary before the user gets all the way to submission.
So the key lesson is that checkout forms are not just a place to gather input. They are the point where UI, stored user data, and domain rules finally meet. That is why they deserve more care than a bare list of fields.