Understanding React-Redux and mapStateToProps()

Q: Is this ok?
A: yes

Q: Is this expected?
Yes, this is expected (if you are using react-redux).

Q: Is this an anti-pattern?
A: No, this is not an anti-pattern.

It’s called “connecting” your component or “making it smart”. It’s by design.

It allows you to decouple your component from your state an additional time which increases the modularity of your code. It also allows you to simplify your component state as a subset of your application state which, in fact, helps you comply with the Redux pattern.

Think about it this way: a store is supposed to contain the entire state of your application.
For large applications, this could contain dozens of properties nested many layers deep.
You don’t want to haul all that around on each call (expensive).

Without mapStateToProps or some analog thereof, you would be tempted to carve up your state another way to improve performance/simplify.

Related Posts:

  1. React Context vs React Redux, when should I use each one?
  2. Local package.json exists, but node_modules missing
  3. This.props.dispatch not a function – React-Redux
  4. Uncaught Invariant Violation: Too many re-renders. React limits the number of renders to prevent an infinite loop
  5. Why use Redux over Facebook Flux?
  6. Await is a reserved word error inside async function
  7. Invariant Violation: Objects are not valid as a React child
  8. Invariant Violation: Objects are not valid as a React child
  9. What is Virtual DOM?
  10. How to use Redirect in the new react-router-dom of Reactjs
  11. React.js: Set innerHTML vs dangerouslySetInnerHTML
  12. React – uncaught TypeError: Cannot read property ‘setState’ of undefined
  13. Understanding unique keys for array children in React.js
  14. How to do a redirect to another route with react-router?
  15. Jest spy on functionality
  16. Difference between npx and npm?
  17. Reactjs – Form input validation
  18. What is mapDispatchToProps?
  19. Error Running React Native App From Terminal (iOS)
  20. Axios Delete request with body and headers?
  21. Loop inside React JSX
  22. Can’t resolve module (not found) in React.js
  23. How to implement navbar using react
  24. Loop inside React JSX
  25. how to render a react component using ReactDOM Render
  26. Console logging for react?
  27. Parse Error: Adjacent JSX elements must be wrapped in an enclosing tag
  28. ‘react-scripts’ is not recognized as an internal or external command
  29. After $npm install, Getting Error: Cannot find module ‘../lib/utils/unsupported.js’
  30. React Native: this.setState is not a function
  31. React: trigger onChange if input value is changing by state?
  32. In reactJS, how to copy text to clipboard?
  33. SyntaxError: Adjacent JSX elements must be wrapped in an enclosing tag
  34. You should not use Route or withRouter() outside a Router when using react-router 4 and styled-component in react
  35. React-Router only one child
  36. What does the className attribute mean in JSX?
  37. What is prevState in ReactJS? [duplicate]
  38. React with ES7: Uncaught TypeError: Cannot read property ‘state’ of undefined
  39. React Hook Warnings for async function in useEffect: useEffect function must return a cleanup function or nothing
  40. Setting a backgroundImage With React Inline Styles
  41. React – TypeError: Cannot read property ‘props’ of undefined
  42. What is the difference between state and props in React?
  43. How to pass props to {this.props.children}
  44. React eslint error missing in props validation
  45. OnChange event using React JS for drop down
  46. ESLint Parsing error: Unexpected token
  47. Setting onSubmit in React.js
  48. How to import image (.svg, .png ) in a React Component
  49. Uncaught TypeError: Cannot read property ‘props’ of null
  50. ReactJS: setTimeout() not working?
  51. React Uncaught Error: Target container is not a DOM element [duplicate]
  52. React Error: Target Container is not a DOM Element
  53. How to implement authenticated routes in React Router 4?
  54. React Js: Uncaught (in promise) SyntaxError: Unexpected token < in JSON at position 0
  55. Console is throwing Unterminated JSX contents error
  56. How to scroll to an element?
  57. How to handle the `onKeyPress` event in ReactJS?
  58. setInterval in a React app
  59. Cannot read property ‘bind’ of undefined. React.js
  60. How do you Hover in ReactJS? – onMouseLeave not registered during fast hover over
  61. Failed to compile. Module not found: Can’t resolve ‘react-router-dom’
  62. ReactJS: setTimeout() not working?
  63. What does “export default” do in JSX?
  64. How to add multiple classes to a ReactJS Component?
  65. Warning: findDOMNode is deprecated in StrictMode. findDOMNode was passed an instance of Transition which is inside StrictMode
  66. Warning: findDOMNode is deprecated in StrictMode. findDOMNode was passed an instance of Transition which is inside StrictMode
  67. React.js – Can’t read property of undefined
  68. module.exports “Module is not defined”
  69. React’s setState method with prevState argument
  70. onEnter not called in React-Router
  71. Pass react component as props
  72. Uncaught TypeError: Cannot read property ‘call’ of undefined at __webpack_require__
  73. Objects are not valid as a React child. If you meant to render a collection of children, use an array instead
  74. How to clear react-native cache?
  75. Async/await in componentDidMount to load in correct order
  76. Access Control Origin Header error using Axios
  77. Cannot read property ‘getHostNode’ of null
  78. how to use react require syntax?
  79. onClick not working React js
  80. React-Router : What is the purpose of IndexRoute?
  81. How to add a keyboard listener to my onClick handler?
  82. React router not showing browser history
  83. e.target.value on an input field ReactJs, how does it work?
  84. Uncaught Invariant Violation: Rendered more hooks than during the previous render
  85. command not found: jest
  86. Jest encountered an unexpected token
  87. ReactJS – .JS vs .JSX
  88. ReactJS: Maximum update depth exceeded error
  89. React, Uncaught ReferenceError: ReactDOM is not defined
  90. How to allow CORS in react.js?
  91. Invariant Violation: _registerComponent(…): Target container is not a DOM element
  92. Uncaught ReferenceError: React is not defined
  93. Expected ‘this’ to be used by class method
  94. How to disable button in React.js
  95. What does “export default” do in JSX?
  96. Update style of a component onScroll in React.js
  97. where is create-react-app webpack config and files?
  98. Correct modification of state arrays in React.js
  99. “React.Children.only expected to receive a single React element child” error when putting and in a
  100. Getting “Cannot call a class as a function” in my React Project

Leave a Comment

tech