Coming from a React background and the nightmare that came with useEffect, componentDidMount, and other component-related challenges, I made it a point to understand the Flutter Widget Lifecycle. I imagine my understanding of the basics in theory will be key in optimizing my app performance and handling conditional rendering. (No different from React, I hope.)

We Start Here

There are three key methods to understand in the Widget Lifecycle:

1. initState()
2. build()
3. dispose()

initState()

initState—as the name suggests—is used for initializing state in a StatefulWidget.

Anatomy of initState()

@override
void initState() {
  super.initState();
}

Good vs Bad Practices in Flutter

Good Practices ✅

1. Use initState() for one-time initialization, calling methods required only once in a widget lifecycle.
2. Always call super.initState(). Don't worry about this—it usually comes built-in. Just don't delete it.
3. Use widget bindings to handle content-dependent actions, like listeners and animation controllers.
4. Use late initialization for expensive objects instead of recreating them.
5. Keep inherited widgets immutable when initializing a widget.

Bad Practices ❌

• Don't call setState inside initState(). You can't set state inside a widget that isn't fully initialized.
• Don't make an async call inside initState(), use a separate method.
• Don't access BuildContext directly in initState().
• Don't recreate expensive objects unnecessarily.
• Don't modify inherited widgets during initialization.

build()

The build() method is executed when the widget is built and called after setState() is called.

dispose()

Called right before a conditionally rendered widget is destroyed.