#1. Warm up: Adding a new user

Let’s start by adding a simple user to the users array and then changing it’s email address.

Easy State knows that UsersApp iterates the users array during its render and it knows that user.email is rendered for every user. From this it deduces, that UsersApp should re-render after each operation.

If you feel like it, follow along with the live example app. Don’t be surprised, it’s an empty page. You can fill it with users from your developer console — like I did.

#2. Dynamic properties

The first example was not that impressive. Let’s see something that is exclusive to ES6 Proxies, by pasting these lines — one by one — to the console.

This time the new user was added by users[1] = newUser instead of push and at first it didn’t have an email. Adding new properties dynamically— like the email — can only be tracked by ES6 Proxies. Older state management libraries won’t re-render the app in these cases.

delete is another operation that was impossible to track until recently. Easy State re-renders the UsersApp if you delete a property which is used during its render.

#3. Property accessors and enumeration

It’s time to take a deeper dive. For this example we will need some preparation code.

Dave is a user with multiple email addresses. A property getter is used to dynamically generate his email, by enumerating the emails object and constructing a string from it.

Easy State knows that Dave’s email is generated from all of the properties in his emails collection. If a new email is added to the collection, it re-renders the UsersApp to reflect it. The same happens when an email is deleted.

#4. The final boss: Inheritance

Let’s see what happens if we throw in prototypal inheritance to the mix. This example will also need a preparation script.

John — the new user — inherits his name and email from Ann — the second user.

If we delete John’s name, it falls back to Ann because of the inheritance.

because of the inheritance. Then editing Ann’s name changes both Ann’s and John’s name.

Finally we add an own name for John again.

Easy State re-renders the App after each of these operations — since all of them results in a different view.