React.js for Noobs ⋅ ElseIf

#ReactJS #Javascript RT @getelseif: React.js for Noobs  #programming #software_development

  • React.js has been popular among web app developers recently and a lot of websites has adopted the library because of the perks it provides.
  • This post is not about pros and cons of the React.js library, although you can find a myriad of articles and posts on the web comparing React.js with other front-end frameworks.
  • In layman’s terms, React.js is a JavaScript library which handles the view component of the MVC architecture.
  • React.js is used to manipulate the DOM of a webpage in an efficient manner to render a web application.

React.js has been popular among web app developers recently and a lot of websites has adopted the library because of the perks it provides. This post is not about pros and cons of the React.js library, although you can find a myriad of articles and posts on the web comparing React.js with other front-end frameworks.
In layman’s terms, React.js is a JavaScript library which handles the view component of the MVC architecture. React.js is used to manipulate the DOM of a webpage in an efficient manner to render a web application.
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a collection of reusable low-level visualization components for #reactjs #d3js

a collection of reusable low-level visualization components for #reactjs 


#d3js

  • vx is a collection of reusable low-level visualization components.
  • (y))], }); Compose together the scale and accessor functions to get point functions ( , ) ( ) ( (data)); (xScale, x); (yScale, y); Finally we’ll embed it all in an SVG ( ) { ( svg width {width} height {height} { .
  • (( , ) { yMax (d); ( Group key { } Bar x { (d)} y {yMax barHeight} height {barHeight} width { .
  • If you’re creating your own awesome chart library on top of vx, it’s easy to create a component api that hides d3 entirely.
  • This collection of components lets you easily build your own reusable visualization charts or library without having to learn d3.

react + d3 = vx | visualization components
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#d3js”

Why Angular 2 Is So Awesome – Jacob Gardner – Medium

Why Angular 2 Is So Awesome  #react #angular2 #angular #javascript #reactjs

  • First you start with a simple route that looks something like this:{ component: SweetComponent, path: ‘fabulousness/:someId’}Pretty straightforward, yeah?
  • Okay, time to dig down into that SweetComponent from earlier and see how it accesses those fields.Your route is polite enough to provide Observables so that the component can make any necessary updates when the route changes, like this:route.params.subscribe(({ someId }) = otherStuff }) = …Convenient, huh?
  • Simply put, it’s a hash of the names for component properties that have changed to corresponding SimpleChange objects.
  • On that note, I’ll just defer to a passage from my entirely hypothetical and nonexistent previous article, Why TypeScript Is So Awesome:Unfortunately, TypeScript’s philosophy tends to encourage a developer to encapsulate values in ES6 classes, much as one would use structs in other languages.
  • When we obfuscate the true nature of JavaScript’s dynamic typing and prototypal inheritance behind a facade of static types and classes, we directly harm inexperienced developers by giving them a false impression of how JavaScript actually works.

Did you want to know what’s so great about Angular 2? Man, that sure was rhetorical. I’m definitely going to tell you regardless. Let’s talk routing; every app worth its salt needs routing. First you…
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Learn the differences between Shadow DOM and Virtual DOM

Learn the differences between Shadow DOM and Virtual DOM →  #VueJS #reactjs

  • Vue.js and React both use Virtual DOM so it is a known concept by many but often it is confused with Shadow Dom.
  • For this reason, an article about which problem Shadow DOM tries to solve and how it differs from Virtual DOM was created by @develoger, made available here.
  • Virtual DOM is about avoiding unnecessary changes to the DOM, which are expensive performance-wise, because changes to the DOM usually cause re-rendering of the page.
  • Shadow DOM is mostly about encapsulation of the implementation.
  • Shadow DOM refers to the ability of the browser to include a subtree of DOM elements into the rendering of a document, but not into the main document DOM tree.

Virtual DOM is a feature of Vue.js and other major frameworks but often there is some confusion between Virtual and not, so some clarification is needed
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Improve Your UX by Dynamically Rendering Images via React

Improve Your UX by Dynamically Rendering Images via React @arwong09  #Reactjs #UX #Startups

  • It’s also how performant it is, how intuitive it is — how much it delights your user.We’ve all been there, discovering a new app or web page for the first time and seeing something like this:With high resolution photos and retina screens, it’s all too often we have to sit and watch images painstakingly render.
  • We accomplish this by using React’s onLoad event; we can make the request to the server for the image files, but not render the image in the DOM until the entire file has been downloaded.the end result: smooth as butterThe end result is an app that loads high resolution images and never keeps the user waiting.
  • The placeholder teases the user and lets them know images are being loaded.
  • Furthermore, we hold off on rendering the images until they have been fully downloaded from the server so our user never has to see images painting from top to bottom in the browser.view live demoShow Me the Code!Rendering the PlaceholderFor our placeholder component (LoadingItem in this example), we simply render the image and apply any animation effects we want:export default function () { return ( ReactCSSTransitionGroup transitionName=”loadingItem” transitionAppear={true} transitionAppearTimeout={500} transitionEnterTimeout={500} transitionLeaveTimeout={300} img className=”feed__loading-item” src={img} / /ReactCSSTransitionGroup )}In the render of our Feed component, we simply render LoadingItem as long as we still have FeedItems being loaded:export default class Feed extends Component { … render() { return ( div className=”feed” … {this.props.items.length this.state.loadedItems.length LoadingItem / } … /div ) }}Dynamically Rendering Images via `onLoad`Our Feed component works as follows:export default class Feed extends Component { constructor(props) { super(props) this.state = { loadedItems: [] } } onLoad(feedItem) { let updatedItems = this.state.loadedItems updatedItems.push({ name: feedItem.name, imgPath: feedItem.imgPath }) this.setState({ loadedItems: updatedItems }) }render() { return ( div className=”feed” h1 i) = FeedItem imgPath={item.imgPath} name={item.name} key={i} / )} {this.props.items.length this.state.loadedItems.length LoadingItem / } div className=”hidden” {this.props.items.map((item, i) = img src={item.imgPath} onLoad={this.onLoad.bind(this, item)} key={i} / )} /div /div ) }}So what’s happening here?
  • When the state updates, the newly loaded item is rendered into the DOM with the image already fully downloaded.That’s it!View live demoView full source code (star the repo if you found this helpful!)

It’s a competitive world out there right now. As we all know, just having a good idea isn’t enough to make your company the next billion dollar IPO. Execution is just as important, and when it comes…
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Functional programming on frontend with React & ClojureScript

“React meets ClojureScript” - An awesome introduction to ClosureScript and React

  • You simply update component internal state and then its UI is re-rendered .
  • To allow reuse of components each of the components has its own unique state accessed via this.state .
  • State of the card is then passed as an argument to function creating React components.
  • Any component that uses an atom is automagically re-rendered when it’s value changes.
  • Distinction between props and state is gone and you are free to use Reagent atoms in any way you prefer.

Blog about Scala, Akka & reactive, functional programming
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The one thing that no one properly explains about React — Why Virtual DOM – ReactJS News

#GE The one thing that no one properly explains about React — Why Virtual DOM  #javascript

  • virtual-dom will then figure out how to make the DOM look like this efficiently without recreating all of the DOM nodes.
  • The particular behaviour can be achieved without a virtual DOM. You can manually group all the DOM modifications in a DOM fragment yourself and then dump it into the DOM.
  • The style information along with the nodes in the DOM tree are used to create another tree, called the render tree
  • All nodes in the DOM tree have an “attach” method, which takes in the calculated style information, and returns a render object (a.k.a. renderer)
  • Author Brian Posted on August 28, 2016 Categories Uncategorized Tags bind , binding , browser operations , Browser workflow , complex SPA , Component , DOM change , engineâ s hood , feet level view , following steps , Form , great deal , great question , JavaScript engines , need , performant , quick detour , real DOM , refreshing huge pieces , render tree , virtual DOM , Virtual DOM abstraction , Virtual DOM rock

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Online Beginner React Course Learn React in 4 weeks

#React Class for Beginners Starts Tomorrow! Enroll now:  #javascript #reactjs #learnreact

  • Check out our intermediate class with Redux !
  • Codementor React Class: Syllabus
  • Classes will be held on Thursday at 6PM PDT / 9PM EDT .
  • The live group lecture is the core of the class.
  • Codementor Live Class enables you to learn hands-on with a live mentor.

Online React courses – learn React live with an instructor, and receive instant feedback.
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