react-state-management.md

React State Management

State Types and Data Flow

• A Visual Guide to State in React
  https://daveceddia.com/visual-guide-to-state-in-react/
  Describes what "state" is, what kinds of data should be included into React state, and how state flow relates to component updates.

• ReactJS: Props vs State
  http://lucybain.com/blog/2016/react-state-vs-pros/
  Explains that "props" are data passed in to a component, while "state" is data managed inside a component.

• Props vs State
  https://github.com/uberVU/react-guide/blob/master/props-vs-state.md
  A quick summary of the differences between "props" and "state" in React components

• The 5 Types of React Application State
  http://jamesknelson.com/5-types-react-application-state/
  Describes different categories of state: data, communication, control, session, and location

• "M" and "C" in "MVC"
  https://www.youtube.com/watch?v=fUpkYixd03k https://github.com/jamesknelson/m-and-c-in-mvc-talk
  James K. Nelson's talk at ReactNext, talking about the multiple categories of state and how controller components can manage them.

• Exploring React's State Propagation
  https://www.sitepoint.com/exploring-reacts-state-propagation/
  Discusses data flow in React, the difference between state and props, and the usefulness of immutability

• Redux'ing without Redux
  https://medium.com/@m.mollaverdi/reduxing-without-redux-75dbd5c05336
  Thoughts on how some of Redux's goodness can perhaps be utilised without actually using Redux.

• Dataflow through React
  https://jurassix.gitbooks.io/dataflow-through-react/content/index.html
  An online book that covers a number of topics on React components and data flow.

• React Anti-Patterns: Props in Initial State
  https://medium.com/@justintulk/react-anti-patterns-props-in-initial-state-28687846cc2e
  Discussion of why using props to initialize a component's state may or may not be a bad idea.

• Best Practices for Component State in React
  http://brewhouse.io/blog/2015/03/24/best-practices-for-component-state-in-reactjs.html
  Some excellent suggestions and approaches for state handling and structure.

• React state management patterns
  http://vijayt.com/post/react-state-management-patterns/
  Useful summaries of some common patterns for managing state (encapsulated vs uni-directional flow, single store or multiple stores, shared state between components).

• Watch Out for Undefined State
  https://daveceddia.com/watch-out-for-undefined-state/
  Discusses the common mistake of making data requests and not having data fields initialized for use in the initial render, and looks at several ways to handle the issue.

• How to Work with and Manipulate State in React
  https://www.sitepoint.com/work-with-and-manipulate-state-in-react/
  Covers how to access and update state in components, the difference between state and props, and working with stateless components.

• Lowest Common Ancestor
  https://blog.embermap.com/lowest-common-ancestor-fbf5d5313a1
  An article that discusses the principle of keeping shared state at the "lowest common ancestor" of the components that need it. Actually talks about Ember, but the concepts are completely applicable to React as well.

• Understanding State and Props in React
  https://hackernoon.com/understanding-state-and-props-in-react-94bc09232b9c
  A helpful explanation of the difference between "props" and "state".

• Local Storage in React
  https://www.robinwieruch.de/local-storage-react/
  Demonstrates how to persist state in React using local storage, how to use it as a cache, and how to make it expire.

• How to manage or eliminate React state without Redux
  http://monicalent.com/blog/2017/07/23/manage-state-in-react/
  An excellent writeup on techniques you can use to help manage state in React without using Redux, including only using component state for things that are really needed, extracting state management logic, and rethinking when you actually need stateful components.

• State management in Javascript
  https://codeburst.io/state-management-in-javascript-15d0d98837e1
  Not React-specific, but some excellent general principles for dealing with state overall: represent data uniquely, derive values, define dependencies, and localise state as much as possible.

Using setState

• React component state cheatsheet
  https://twitter.com/dan_abramov/status/749710501916139520
  Dan Abramov pseudocodes his guidelines for when to put something into component state

• Where to Hold React Component Data: state, store, static, and this
  https://medium.freecodecamp.com/where-do-i-belong-a-guide-to-saving-react-component-data-in-state-store-static-and-this-c49b335e2a00
  A great summary of different places to store state, and when and why you should use each.

• How to handle state in React: The Missing FAQ
  https://medium.com/react-ecosystem/how-to-handle-state-in-react-6f2d3cd73a0c
  An article that dispels misunderstandings and answers common questions about how to handle state in React.

• Finding state's place with React and Redux
  https://medium.com/@adamrackis/finding-state-s-place-with-react-and-redux-e9a586630172
  A look at when and how using React component state may be useful, even when using Redux for primary app state

• A case for setState
  https://medium.com/@zackargyle/a-case-for-setstate-1f1c47cd3f73
  An article arguing that React component state still has a number of uses.

• Using a function in setState instead of an object
  https://medium.com/@shopsifter/using-a-function-in-setstate-instead-of-an-object-1f5cfd6e55d1
  An introduction to a lesser-known feature of setState: the ability to pass a callback function to update the state. Useful for ensuring proper updates.

• "Best kept React secret: declare state changes separately from component classes"
  https://twitter.com/dan_abramov/status/824308413559668744
  Dan Abramov shows some screenshots that demonstrate how to define state update functions outside a component, then pass them to setState

• Functional setState is the future of React
  https://medium.freecodecamp.com/functional-setstate-is-the-future-of-react-374f30401b6b
  Discusses passing a function to setState to perform updates, why that approach is useful, and how that pattern can be used to separate state update logic from component definition

• **Does React have a setState problem? / setState() Gate: Navigating Behavior Confusion** https://twitter.com/i/moments/842710066826530816 https://medium.com/javascript-scene/setstate-gate-abc10a9b2d82 Eric Elliott recently posted a tweet saying that setState` is bad for learners, and advanced devs have learned to avoid it. That spawned a large Twitter thread arguing the idea. Elliott later posted an article explaining his concerns in detail. Some excellent reading and points to consider all around - the "Moments" link includes a few of the tweets, but the whole thread is worth reading.

• Understanding ReactJS: setState
  https://medium.com/@baphemot/understanding-reactjs-setstate-a4640451865b
  Several helpful tips and concepts for understanding how component state and setState work, including how to initialize component state, ways to call setState, and common errors.

• Stack Overflow: "Do I need to use setState(function) overload?"
  http://stackoverflow.com/questions/43428456/do-i-need-to-use-setstatefunction-overload-in-this-case/43440790#43440790
  Dan Abramov gives a great in-depth answer explaining when and why to pass an updater function to setState instead of passing an object

• "setState doesn't actually care whether you've mutated your data or not"
  https://news.ycombinator.com/item?id=14706862
  A couple comments from myself, talking about how setState actually behaves in practice in relation to mutation and immutability.

• Atomic setState Updates in React
  https://alligator.io/react/getting-atomic-updates-with-setstate/
  Discusses how the standard object form of setState can cause race conditions, while the functional form is more predictable.

• setState ftw
  https://speakerdeck.com/michelebertoli/setstate-ftw
  Slides from Facebook dev Michele Bertoli's talk on how setState works, how to use it properly, and useful techniques for working with setState.