Comprehensive Flow with React & Redux – Jiri Kolarik – Medium

Comprehensive Flow with React & Redux  #flow #flowtype #react #reactjs #redux #reactjs

  • This is bit boilerplate, you have to say what goes in and what action is returned including a type but in this case not only a string, but exactly the same constat.//@flowexport type AppLocaleChangeType = { type: ‘APP/LOCALE:CHANGE’, locale: string};export function appLocaleChange(locale: string): AppLocaleChangeType { return { type: APP.LOCALE.CHANGE, locale…
  • Now we see in our switch/case what action are we dealing with and what options do we have.//@flowimport type { ActionType } from ‘actions/index’;export type AppState = { +locale: string}const initState: AppState = { locale: ‘en’}export default function reducer(state: AppState = initialState, action: ActionType) { switch (action.type) { case APP.LOCALE.CHANGE:…
  • /app’;export type State = { +app: AppState}ComponentsRight now, we know how the state may look like and whatever actions we can use// @flowimport React from ‘react’;import { connect } from ‘react-redux’;import { appLocaleChange } from ‘actions/app’;import type { Dispatch } from ‘actions/index’;type Props = { dispatch: Dispatch}const Language = (props:…
  • // @flowimport React from ‘react’;import { connect } from ‘react-redux’;import { appLocaleChange } from ‘actions/app’;import type { State } from ‘store/types’;import type { Dispatch } from ‘actions/index’;import type { MapStateToProps } from ‘react-redux’;type OwnProps = { visible: boolean}type StateProps = { locale: string}type Props = { dispatch: Dispatch} OwnProps StatePropsconst…
  • props.visible) { return null; }const onChange = (event: SyntheticEventEventTarget) = { if (event.target instanceof HTMLInputElement) { } };return ( div className=”css-select” styleName=”select” select onChange={onChange} defaultValue={props.locale} option value=”EN”English/option option value=”CS”Czech/option /select /div );};const mapStateToProps: MapStateToPropsState, OwnProps, StateProps = (state) = ({ locale: state.app.locale});export default now you should have access to all…

Before I start, I’d like to say, that this is my very first article. I’m not good in writing or expressing my self in my native language and in English is even bit worse, but I haven’t found an…
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Impress Your Friends With Code Splitting in React – Hacker Noon

Impress Your Friends With #Code Splitting in #ReactJS:  by @burkeholland #JavaScript

  • Both of those actions show the edit form.First I am going to add a spot in my state for this “EditForm” component to live.class Heroes extends Component { constructor(props) { super(props); this.state = { …, lazyEditHero: null } } …, render() { return ( … ) }}I put mine in…
  • I have put this in a function called LoadEditFormclass Heroes extends Component { constructor(props) { super(props); this.state = { … lazyEditHero: null } } async LoadEditForm() { const { default : EditHero } = await import(‘.
  • /EditHero’); this.setState({ lazyEditHero: EditHero }) } render() { return ( … ) }}Now we just need to call this LoadEditForm from the two functions that trigger the editor component to be shown.class Heroes extends Component { constructor(props) { super(props); this.state = { … lazyEditHero: null } } async LoadEditForm() {…
  • /EditHero’); this.setState({ lazyEditHero: EditHero }) } handleSelect = async hero = { await this.LoadEditForm(); this.setState({ selectedHero: hero }); } handleEnableAddMode = async () = { await this.LoadEditForm(); this.setState({ addingHero: true, selectedHero: { id: ”, name: ”, saying: ” } }); } … render() { return ( … ) }}A few…
  • This also allows us to pass any props to our component when it is so lazily loaded.class Heroes extends Component { constructor(props) { super(props); this.state = { … lazyEditHero: null } } async LoadEditForm() { const { default : EditHero } = await import(‘.

In preparation for the DevUp keynote a few weeks ago, I took some time to learn the minimum amount possible to demonstrate code splitting in React. Now your first reaction is probably… As part of the…
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Redux: Persist Your State – Async LA – Medium

Redux: Persist Your State  #redux #react #reactnative #reactjs #reactjs

  • You create your store from scratch, initialize state, and maybe set some basic state based on the url (if you are in a browser).
  • But the blob could be days, weeks or years old!Redux Persist provides a consistent, performant, and structured way to persist state.If you still require more convincing, read Jani Eväkallio’s piece on offline first applications.Part 2: Architecture2.1 The Component PartsThe “persistence layer” is actually two stateful reactive objects, plus a higher…
  • It also creates register and rehydrate methods which will be used to register each persistoid, and dispatch the actual rehydrate action respectively.PersistoidThe persistoid is the actual state sink.
  • additionally it handles the PURGE action for clearing stored state.2.2 Whats new in Redux Persist v5code splitting reducersbetter integration story for libs (e.g. redux-offline)ability to colocate persistence rules with the reducer it pertains tofirst class migration supportenable PersistGate react component which blocks rendering until persistence is complete (and enables similar patterns…
  • Thats means a consistent story around extensibility, and the ability to use redux-devtools to debug any tricky issues internal to the persistence layer.Ergonomic ReduxVanilla Redux requires a ton of ceremony to use.

When your app reloads, the javascript process has nothing in memory. You create your store from scratch, initialize state, and maybe set some basic state based on the url (if you are in a browser)…
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The joy of React+Redux with Elixir/OTP

The joy of React+Redux with Elixir/OTP  #ReactJS #Redux #Elixir

  • Graphically, this is the schema of a Redux app: – – Basically, Redux does the following: – – An OTP GenServer does the following: – – In short, we can use the same mental model for the client and server side.
  • We can dispatch events to Elixir, compute a new version state server side, propagate this state to redux, and our views will get updated automatically.
  • We have just implemented the thick red arrows: – – We will update the store with the state that comes from the server in two different situations.
  • With this, we have connected the server state with Redux state.
  • But, if you want to have state shared between different users, or we want to have pieces of the state in the server for other reasons, such as enforcing validation rules, we can use the same mental mode with Elixir GenServers.

Digital solutions partner. High quality work with Symfony, React and Elixir.
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React.js: The Hard Parts

State Management without #Redux:  by #ReactJS

  • If a user interacts with your application or refreshes the page, then we’ll look up state at that moment and rebuild the page.
  • In dynamic apps, like ones built using React, state change has to be dealt with immediately.
  • Managing state can get complicated if each component has some state.
  • Interaction with the components, like a mouse click, trigger these functions to update state.
  • For example to implement retweets: – – When the state is updated, the props will change too and render the child components again.

I am a full-stack software developer and passionate educator. I have been building for the web for almost two decades.
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8 things to learn in React before using Redux

8 things to learn in #ReactJS before using #Redux:

  • A component can manage a whole lot of state, pass it down as props to its child components and pass a couple of functions along the way to enable child components to alter the state in the parent component again.
  • Component A is the only component that manages local state but passes it down to its child components as props.
  • In addition, it passes down the necessary functions to enable B and C to alter its own state in A.

    Now, half of the local state of component A is consumed as props by component C but not by component B.

  • When you lift the local state management down to component C, all the necessary props don’t need to traverse down the whole component tree.
  • When a library such as Redux “connects” its state managements layer with React’s view layer, you will often run into a higher order component that takes care of it (connect HOC in react-redux).

Facts about React that should be known before using Redux (or MobX). Most important: Learn React first, then opt-in Redux…
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