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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How to Build a Todo App Using React, Redux, and Immutable.js — SitePoint

  • This helps us get a feel for what we’re going to need our components to render:
    const dummyTodos = [
    { id: 0, isDone: true, text: ‘make components’ },
    { id: 1, isDone: false, text: ‘design actions’ },
    { id: 2, isDone: false, text: ‘implement reducer’ },
    { id: 3, isDone: false, text: ‘connect components’ }
    ];

    For this application, we’re only going to need two React components, Todo / and TodoList /.

  • js

    import React from ‘react’;

    export function Todo(props) {
    const { todo } = props;
    if(todo.isDone) {
    return strike{todo.text}/strike;
    } else {
    return span{todo.text}/span;
    }
    }

    export function TodoList(props) {
    const { todos } = props;
    return (
    div className=’todo’
    input type=’text’ placeholder=’Add todo’ /
    ul className=’todo__list’
    {todos.map(t = (
    li key={t.id} className=’todo__item’
    Todo todo={t} /
    /li
    ))}
    /ul
    /div
    );
    }

    At this point, we can test these components by creating an index.html file in the project folder and populating it with the following markup.

  • /components’;

    const dummyTodos = [
    { id: 0, isDone: true, text: ‘make components’ },
    { id: 1, isDone: false, text: ‘design actions’ },
    { id: 2, isDone: false, text: ‘implement reducer’ },
    { id: 3, isDone: false, text: ‘connect components’ }
    ];

    render(
    TodoList todos={dummyTodos} /,
    the code with npm run build, then navigate your browser to the index.html file and make sure that it’s working.

  • Our dummy data is a great place to start from, and we can easily translate it into ImmutableJS collections:
    import { List, Map } from ‘immutable’;

    const dummyTodos = List([
    Map({ id: 0, isDone: true, text: ‘make components’ }),
    Map({ id: 1, isDone: false, text: ‘design actions’ }),
    Map({ id: 2, isDone: false, text: ‘implement reducer’ }),
    Map({ id: 3, isDone: false, text: ‘connect components’ })
    ]);

    ImmutableJS maps don’t work in the same way as JavaScript’s objects, so we’ll need to make some slight tweaks to our components.

  • The mapStateToProps function takes the store’s current state as an argument (in our case, a list of todos), then it expects the return value to be an object that describes a mapping from that state to props for our wrapped component:
    function mapStateToProps(state) {
    return { todos: state };
    }

    It might help to visualize this on an instance of the wrapped React component:
    TodoList todos={state} /

    We’ll also need to supply a mapDispatchToProps function, which is passed the store’s dispatch method, so that we can use it to dispatch the actions from our action creators:
    function mapDispatchToProps(dispatch) {
    return {
    addTodo: text = dispatch(addTodo(text)),
    toggleTodo: id

Dan Prince shows how to build a Todo app using React, Redux, and Immutable.js.
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Power of #TypeScript for #React part 3 is ready 🚀 Today looking at Actions #JavaScript…

  • Actions are a really helpful way to create separation between the different layers of an application, because they are not tightly coupled each layer can be built and tested in pieces.
  • It does bring it’s challenges however, whilst the code is loosely coupled, all areas of the code which interact with the action need to have the same expectation of it’s structure.
  • At Seccl all our actions follow the same basic structure and TypeScript allows us to define what that is by using an .
  • So now that we know the flavours, let’s look at an example of our action interface in the wild.
  • What we will create is an interface which describes the called and an action creator which builds the action.

Frontend leadership, Frontend architecture, HTML(5), JavaScript (OOJS, ES6, TypeScript), CSS (BEM, Less, SASS, Stylus), Testable Code (Mocha, Sinon, Chai, Karma), NodeJs (Express, Mongoose) , Cloud Applications (Heroku, S3, Azure)
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ReactJs the simple way – Reduce boilerplate code and enjoy React

#reactjs the simple way – Reduce boilerplate code and enjoy React!

  • It contains actions to update the state, stores to hold it and a dispatcher to coordinate the changes, but the truth is that the important statement of flux is the unidirectional data flow: When the state is updated, the application is re-rendered reactively, so it is the state who rules the application.
  • Flux definition, including stores, actions and a dispatcher, usually explains the unidirectional data flow in a more complex way that it should.
  • It’s a data structure that triggers events when it is updated, and it happens to contain all the needed to add the unidirectional data flow to your app.
  • Every time the state is updated, Freezer create a new immutable object for it reusing the unmodified parts of the data tree.
  • Let’s see the code of the todo update reaction:

    You might be thinking that having the input values outside the components will re-render your whole app every time the user types.

ReactJs the simple way – Reduce boilerplate code and enjoy React
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Redux with React – First Look #reactjs #Redux #javascript #appdev #programming #devops

Redux with React - First Look  #reactjs #Redux #javascript #appdev #programming #devops

  • Let’s start with the basics:

    According to the official site Redux is defined as a predictable state container for JavaScript apps.

  • In Redux, reducers are functions (pure, I will explain what a pure function is later) that take the current state of the application and an action and then return a new state.
  • 3 – Store

    Store is the object that holds the application state and provides a few helper methods to access the state, dispatch actions and register listeners.

  • – Changes are made with pure functions: To specify how the state tree is transformed by actions, you write pure reducers.
  • You might be interested in:

    Predictability of outcome:

    There is always one source of truth, the store, with no confusion about how to sync the current state with actions and other parts of the application.

influenced by Flux architecture and became popular very quickly, excellent documentation and size (2 KB). Also it is very easy to use redux with react
Continue reading “Redux with React – First Look #reactjs #Redux #javascript #appdev #programming #devops”

Introduce Redux local state to your React App – t-benze – Medium

Introduce Redux local state to your React App  #redux #react #reactjs

  • In this way I can extract the data fetching logic into actions and reducers, and take them out from the component to make sure the component is only dealing with UI stuff, and let actions and reducers handle the business logic.So narrow down the problem, what I want is the capability to create local state that is bound to an component in the redux store, which only lives within the component’s lifecycle, and still enjoy the benefits redux has provided (actions, reducers, middleware).
  • Our requirements are as follows:the component using local state should be able to access the global redux state naturallythe api to connect to local state should be similar as the connect function from react-reduxthe actions dispatched for local state need to work normally with redux middlewarethe actions and reducers need to be agnostic to whether they’re used with respect to local state or global stateImplementationThe local state in redux can be implemented as an add-on to redux quite straightforwardly.
  • To fix this, we create another middleware to apply after the redux thunk middleware.Since the actions dispatched by the local mapDispatchToProps will be scoped like the one below, redux thunk will now handle it and then our middleware will get to handle it, and if we see the localAction is a function, then we call the function as what thunk would do, but pass in the a localDispatch function and a localGetState function as the first two parameters, followed by dispatch and getState function for global state.
  • { type: ‘$LOCAL_DISPATCH_ACTION’, localAction: (localDispatch, localGetState) = {…}, id}ExampleBelow shows a simple app that has one counter reducer in the global state, along with a local reducer, which is empty at the beginning.Once we click show local to create a component that has its local state and reuse the counter reducer, an new state instance with unique id is registered in the local reducer.Within the component, we can dispatch both global actions and local actions, and they won’t affect each others.Once we remove the component, its local state will get discarded the state management in our app is a mixture of different approaches.
  • We have some UI components using setState() to mange their internal UI state that doesn’t concern others, we have some global application state like user info stored in the global redux store, and we also have some page containers which store its feature data in its local redux state.

I’ve been using redux in my recent projects, including both react web and react-native, and I really like its way of managing application state: one single data source, using actions and reducers to…
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Redux vs Flux – Gina Yeon – Medium

Redux vs Flux  #redux #react #reactjs

  • Redux vs FluxGoing into Redux, I wanted to see the difference in patterns between the two.The general gist of Redux is that the entire state of your app is stored in an object tree inside a single store.
  • Pure reducers will then specify how those actions transform the state tree.The single major difference between Flux and Redux is that Redux doesn’t have a Dispatcher, or support many stores.
  • Instead, there is just a single store with a single root reducer.Action creators in Redux differ from action creators in Flux by forgoing sending the action to the dispatcher, and instead returning a formatted action object to the store.The store delegates the work to the reducers by sending them what specific state change they need to update.The root reducer will split the actions up and send it to the respective reducer.
  • Instead of changing the state completely, they make a copy of the current state, and send back the state changes made on that copy.The smart components are in charge of the actions.
  • The dumb components, or presentational components are mainly in charge of laying out DOM elements.The view layer binding connects the store to the views by introducing three concepts:The Provider component — uses the connect() method to link up the component’s children to the store.Connect() — is a function that will set up all the wiring to get state updates using the selector.Selector — specifies what parts of the state a component needs as properties.It will then trigger a re-render updating all the state changes in the views.Resources:Cartoon Intro to Redux

The general gist of Redux is that the entire state of your app is stored in an object tree inside a single store. The only way to change the state tree is to emit an action (object). Pure reducers…
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