Previous State

[00:00] First things first, I'm going to change this setCount to, whoops, right there, to changeCount. And now we're going to change it by the step. So this will be plus the step, this will be minus the step. That is the API that we're looking to create.

[00:17] And so to make that API work, this state is going to be the current count. We'll just call it the count. And now we know for sure it's a number. And this action, the second argument here, this is now going to be the change, the amount that our count is going to change.

[00:35] So the new count is going to simply be the count plus the change, whatever that change is. And that allows us to have this new API, which allows us to say changeCount. And there we go. We increment and decrement. We can change the step. And now we're incrementing by fours,

[00:53] all because we changed the implementation of our reducer. We were able to change the name of this to be something that actually describes what is going to happen when you call that function. There you go.

[00:00] OK, so we're going to continue our useReducer exploration by updating the setCount to actually be a changeCount function and then pass just the change we want. This will mean that we need to know what the current state is, and then we'll get the change that we want to make.

[00:18] We return the result. So changing our reducer, changing the API a little bit, let's go.

Advanced React APIs covers many of the React API that you might not see on a day-to-day basis but you will need these in your toolbelt for certain scenarios that pop up.

We'll take a tour of several advanced hooks and React API, their use-cases, and when to use them. 

These will include:

- useReducer
- use
- createContext
- useLayoutEffect
- useImperativeHandle
- useSyncExternalStore
- flushSync
- createPortal


## Complex State Management

First we'll dive into the deep-end of state management with `useReducer`. This hook comes in really handy when you feel the logic in your components is a sprawling mess and you'd like to consolidate that into a single place with a nice API to interact with. 

We'll get into some state optimizations as well as how to make your logic easily sharable throughout your application with custom hooks.

## Context

While context is often times something you will leave up to library authors, there are some cases where you want to expose values you need throughout your application. We'll build a context provider that will expose search params to our components on a blog search page with `use` (previously `useContext`) and `createContext`.

You'll also refactor this code to expose the context you create in a custom hook that will give us nice error handling when context isn't set up correctly.

## Portals

React gives us `createPortal` to render UI outside of the DOM tree structure that a component might sit in. This is useful for UI elements like modals or tooltips. We'll explore how to attach a tooltip to the `document.body` to ensure it's positioned where it needs to go.

## Layout Computations

If the logic that you are working with in a `useEffect` affects the how the UI looks, especially on first render, you'll want to `useLayoutEffect`. You'll work through an exercise where the client makes calculations on where to place a tooltip before rendering and see the difference when this is in a `useLayoutEffect`.

## Imperative Handles

`useImperativeHandle` is an escape hatch in React that lets you imperatively tell React what to do. This hook is typically paired with a ref (from `useRef`) where we want to expose imperative methods to developers who pass a ref prop to our components.

## Focus Management

`flushSync` is technically a 'de-optimization' because it forces React to re-render whenever you call it. This means you need to be very careful and know what you're doing when you use it.

The primary use-case for this API is focus management. When you have conditional UI that gets rendered based on various state conditions, you can `flushSync` to ensure elements are in the DOM to properly focus.

## Sync Exernal Store

There are some cases where we want to synce our React code with the external world and display different UI based on the state of the external world. This is where `useSyncExternalStore` is useful and lets you subscribe to external stores. We'll also touch on server rendering as this hook supports that use-case.

Learn the hooks and API that React has to offer for complex state management, sharing context throughout your app, focus management and more.

Advanced React APIs

React Fundamentals

React Hooks

React Suspense

Advanced React Patterns

React Performance

React Server Components

Epic React Pro

Advanced React APIs Intro

Intro to Advanced State Management

New State

State Object

Action Function

Traditional Reducer

Real World

Dad Joke Break Advanced State Management

Advanced State Management

Intro to State Optimization

Optimize state updates

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State Optimization

Intro to Custom Hooks

Hook Function

useCallback

Dad Joke Break Custom Hooks 

Custom Hooks

Intro to Shared Context 

Context Provider

Context Hook

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Shared Context

Intro to Portals

createPortal

Dad Joke Break Portals 

Portals

Intro to Layout Computation 

useLayoutEffect

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Layout Computation

Intro to Imperative Handles

useImperativeHandle

Dad Joke Break Imperative Handles 

Imperative Handles 

Intro to Focus Management 

flushSync

Dad Joke Break Focus Management 

Focus Management

Intro to Sync External State 

useSyncExternalStore

Make Store Utility

Handling Server Rendering

Dad Joke Break Sync External State

Sync External State

Outro to Advanced React APIs

Advanced React APIs

Advanced React APIs

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Previous State

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