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
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My Simple React Tutorial. – Jeffrey Doyle – Medium

My Simple React Tutorial.  #webdevelopment #react #reactjs #javascript #apps #reactjs

  • In this case, a state object might look like:state = {currentTime {hour: 0, minute: 0, second: 0}, alarms: [], timeZone: ‘PST’}Say again that you’re creating a component which represents a list of items stored in a table.
  • In this case you’re going to want to store the items in the list, maybe the size of the list, and also the label the list has all inside that components state.
  • Now some developers will say that i’m storing too much inside my state object, but personally I like to keep all of the relevant data to my component inside that components state.
  • Lets explore our example of the list of items component and see what it might look like:As you can see, the state is where all of our data is stored inside our component.
  • When addItem is called and it performs the setState function on the component, the components state will change, and thus trigger the component to re-render according to the new state object, thus including the new item in the list.

React is one of the most powerful Javascript frameworks around right now, this tutorial will introduce you to React, and tell you why you need to start using it right now. Let’s face it, if you’ve…
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React Components Explained – Manoj Singh Negi – Medium

“React Components Explained” by @manojnegiwd  #reactjs #NodeJS #javascript #coding

  • Something like thisimport React from ‘react’;class MyComponent extends React.Component { render () { return div This is a component /div }}class MyOtherComponent extends React.Component { render () { return ( div MyComponent / /div ) }}This way you are able to compose more complex and useful user interface for your users.
  • Component’s render method return JSX which then use to create real HTML output which will be rendered in the browser.The interesting Thing about render method is that it runs every time when your component State or Props updates.
  • Let me show you a exampleimport React from ‘react’;class MyComponent extends React.Component { constructor(props) { super(props); this.state = { name: “Manoj” }; } render () { return div My name is {} /div }}// if we render this component the output will beMy name is ManojIgnore the super(props) (out of the scope of this article) focus on this.state this is where our component state lives.
  • Let’s see an example.class MyComponent extends React.Component { constructor(props) { super(props); this.state = { name: “Manoj” }; this.changeName = this.changeName.bind(this); } changeName () { this.setState({ name: “Your Name” }); } render () { return div onClick={this.changeName} My name is {} /div }}In the above code we are telling our React component to call this.changeName whenever user clicks on the div.
  • You can run this code on jsFiddle here.PropsVisualise props as options that can be passed to a component to customize its functionality.For example, I have a heading component which renders a heading with subtitle.class MyHeading extends React.Component { render () { return div h1This is a heading/h1 pSubtitle/p /div }}If I will use this component it will always render same HTML, someting like this.This is a headingsubtitleIf we use our component in this way it is not of much use right ?

The simplest library I ever used in my life is React. As you know Reac hit is based upon component design. Everything in React is a component which makes it easy to reuse components frequently. You…
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Thoughts on Redux – Pietro Ghezzi – Medium

Important read: Thoughts on #Redux  #ReactJS #JavaScript

  • Mostly for CRUD operations.The first problem was to denormalize the entire state (the use of the library “normalizr” is encouraged by redux docs, I didn’t know it when I started and I did it manually) in a way to split it in small pieces, each with a reducer.
  • It’s useful and speeds up a lot the development process.DemoSummary of my pros and consProsTest driven development is made easy, thanks to pure functions, and increases the development productivityOnly the root component (I call it container) is connected to the reducer, all the actions and state are passed through props.
  • This makes it easy to use component composition and write stateless components.Code linearity, everything is simple and doesn’t differ much from one project to another.Immutability: forcing to keep an immutable state helps a lot avoiding weird bugs.The Log middleware in dev mode, showing all the different states before and after an action is dispatched, is of a great help.ConsIt’s difficult to handle relationships and there isn’t any official library with documentation and support to help you with it.Redundant code, every action is written manually, even the most common, like changing an attribute of the state.Normalizing a complex state with many level of nested objects doesn’t always seem the best approach.My best practicesDirectory structure by module instead of scope.
  • A better approach it could be to retrieve the new state from the server when necessary and handle the state relationships on the database layer.TDD on reducers, tests on reducers not only speed up the development but also cover you on possible “silent” bugs on the state.Keep components simple and use component composition.Normalize the state with the use of Reselect libraryHandling complex store relationships (#386)Note from Dan AbramovDeleting is always tricky because there is no first class notion of a schema.
  • These reducers will know when to remove IDs from foreign key fields because they know what the schema looks like.Dependencies I will consider in for managing complex form stateRedux-ormA small, simple and immutable ORM to manage relational data in your Redux store.It would be great if CRUD operations were managed with the model declaration with no need to write actions manually.Redux UIGood solution to separate the UI state from the application state.NormalizrLibrary suggested in the official redux documentation for normalizing the application state.Main dependencies for this projectReactReduxReact router v2Redux ThunkReact DnDReselectStyled componentsReact BootstrapBootstrap Material DesignJestConclusionRedux is a good solution for handling complex interface, it is very similar to flux architecture, but if I have to rewrite the application, I would do it in a different way.I would avoid to specify all the logic on the client, moving a part on the server side.A good approach I have seen in some projects, it is to dispatch the actions to the server and with a websockets connection, notify all the connected clients of the changes made.This way the client is responsible only to denormalize and normalize the state received by the server, handle the UI state and presenting the data.On the server side is much easier to handle relationships with an ORM provided by a web framework.This project has been of a great help to make me understand all the caveats redux can reserve for a medium size application.

I have been working on my first project with Redux for the last few weeks. An admin interface to manage and create questionnaires about patients data collection. When writing a small application…
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Redux for state management in large web apps

How we use the Redux + React architecture in Mapbox Studio   #redux #reactjs

  • Our Redux architecture boils down to three highly patterned function types: reducers, action creators, and selectors.
  • Slice reducers interpret actions to make changes to specific sub-stores within the single Redux store

    Each slice reducer ends up looking something like this (using the stylesheet sub-store as an example):

    This slice reducer pattern organizes both our code and our thinking.

  • Studio’s React components invoke action creators to trigger changes to the application state, each change represented by an action.
  • To manage asynchronous actions, we use redux-thunk, Redux middleware that allows your action creators to return functions, not just action objects.
  • Our Redux architecture shows how a set of simple concepts — stores, reducers, action creators, and selectors — can effectively organize large applications.

Building a state management system around Redux has allowed us to keep the complex Mapbox Studio (our version of Photoshop for maps) codebase manageable and testable. We’ve used Redux to establish interlocking systems defined by clear, scoped responsibilities and repeatable patterns. We impose restrictions on what code we put where to to make the codebase as a whole more organized, predictable, legible, and testable. These patterns also allow us to increase the quantity of code as the application grows without adding complexity to the architecture. (For those new to Redux, this is a must read 101).
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SVG in React – Etleap

If you want to use SVG in #ReactJS, here's a handy guide:

  • This component uses SVG to display the circular progress bar and works just like any other React component.
  • The reason we opted for SVG in this case was that creating a circular progress bar in CSS is tricky.
  • The essential SVG markup required to render the progress bar is very simple:

    We need two circles, one for the dark background, and one for the lighter progress display.

  • SVG should not be a replacement for all graphical user elements, but can be used to more easily achieve tricky UI effects where CSS falls short.
  • That being said, CSS is catching up with SVG and has seen support for several filters, masks, and even custom clip paths.

React.js is a great library for creating user interfaces consisting of components. In the browser React is used to output DOM elements like divs, sections and.. SVG! The DOM supports SVG elements, so there is nothing stopping us from outputting it inline directly with React. This allows for easy creation of SVG components that are…
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