React Context Demo

• Prop Drilling

• React Hooks

• Context API

• Context Providers

• Shared State

• Interface vs Implementation Functions !!

• Simple Auth / Login App

• Demonstrates Context Providers and useContext

• accepts any username / email address & password

• creates a dummy userId for the newly logged in user

• sets auth state if logged in and shows User Info if auth=true

• uses CounterProvider component to wrap <Info> and <Login> in Appjs

• uses AuthProvider component to wrap <App> in index.js

• Do not share "implementation" functions: setCounter(), setUser().

• Only share "interface" functions: increment(), clear(), login()

• Can share state primitives, just don't share their setState functions

• Its generally "OK" to share more complex state objects eg user

• Sharing a function is better: isloggedIn(), getUserName()

• Avoid deeply nested State. eg: No state object

• Keep your state as flat as possible