In this episode of Syntax, Scott and Wes talk about state in React: local state, global state, UI state, data state, caching, API data and more!

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Show Notes 3:38 - What is state?

4:58 - What kind of things are kept in state?

• Data
  • Temporary client side data
    • From forms, button clicks, etc.
  • Cached server data
  • Data from API
• UI status
  • AKA isModalOpen
  • isToggled

12:48 - Global state vs. Local state

• Ask yourself: does the data need to be accessed outside this component?
  • If data does need to be accessed a little higher, you can simply move where that state lives. React calls this “lifting state”.
• Do you count Apollo API calls as global state?

21:15 - Managing Local state

• useState, setState
• Passing state & update functions down
• State machines

31:12 - Approaches to Global state

• Redux

  • Complicated, hard to learn
  • Very useful, organized and structured
  • Actions, reducers and more
  • Time traveling do to nature of store
  • Immutability
  • Tons of Redux based hooks libs

  • Mobx

  • Based on Observables

    • An Observable is like a Stream and allows to pass zero or more events where the callback is called for each event. Often Observable is preferred over Promise because it provides the features of Promise and more.

  • Context

  • Functions just work and update global state.

  • Downside is there are no fancy tools

  • Apollo

  • Apollo quires for data in global cache

  • Apollo client for global UI state
    • Not quite there, isn’t super elegant

Links * Thinkso * Learn Node! * Meteor Session * xstate-react * React Context * Mobx * easy-peasy * hype.codes * providerCompose.js * Relay * React Podcast

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