virtual-dom | simple virtual-dom implementation

by Dreamacro TypeScript Version: Current License: MIT

X-Ray Key Features Code Snippets Community Discussions(10)Vulnerabilities Install Support

kandi X-RAY | virtual-dom Summary

virtual-dom is a TypeScript library typically used in Utilities, React applications. virtual-dom has no bugs, it has no vulnerabilities, it has a Permissive License and it has low support. You can download it from GitHub.

a simple virtual-dom implementation for understanding how it works.

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Quality

Security

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Support

virtual-dom has a low active ecosystem.

It has 21 star(s) with 2 fork(s). There are 2 watchers for this library.

It had no major release in the last 6 months.

virtual-dom has no issues reported. There are no pull requests.

It has a neutral sentiment in the developer community.

The latest version of virtual-dom is current.

Quality

virtual-dom has no bugs reported.

Security

virtual-dom has no vulnerabilities reported, and its dependent libraries have no vulnerabilities reported.

License

virtual-dom is licensed under the MIT License. This license is Permissive.

Permissive licenses have the least restrictions, and you can use them in most projects.

Reuse

virtual-dom releases are not available. You will need to build from source code and install.

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virtual-dom Key Features

No Key Features are available at this moment for virtual-dom.

virtual-dom Examples and Code Snippets

No Code Snippets are available at this moment for virtual-dom.

Community Discussions

Trending Discussions on virtual-dom

Why React is not rendering after change in state? [functional component]

What does it mean by virtual dom is in-memory?

React Component Lifecycle

esbuild fails without parcel installed

Array list from AsyncData/fetch rendered by v-for throw: The client-side rendered virtual DOM tree is not matching server-rendered

What is it about Vue that enables developers to use the class property on DOM elements?

Missing calls in the Chrome devtools js flamechart

Error on installing NoRedInk/elm-decode-pipeline with Elm 0.19.1

ReactJS virtual DOM in memory and applying incremental changes

How to create your own babel processor alternative to `React`

QUESTION

Why React is not rendering after change in state? [functional component]

Asked 2021-Mar-23 at 18:28

import React, {useState, useEffect} from 'react';

import MakeCard from './MakeCard.js';

export default function GameCards(props) {
  const [images, setImages] = useState([{}]);

  // Render component after fetching images
  useEffect(() => {
    getImages(props.cards).then(images => setImages(images));
  }, [props.cards]);

  // shuffle images and update state.
  const shuffleCards = (e) => {
    console.log("clicked");
    let newImages = images;
    for (let i = newImages.length - 1; i >= 0; i--) {
      let temp, j;
      j = Math.floor(Math.random() * i);
      temp = newImages[i];
      newImages[i] = images[j];
      newImages[j] = temp;
    }
    setImages(newImages);
    console.log("newImages: ", images);
  }

  if (images.length === 0) {
    return (Loading...)
  } else {
    return (
      {
        images.map((image, i) => )
      }
    )
  }
}

...

ANSWER

Answered 2021-Mar-23 at 18:24

You are mutating the original images array.

You set newImages = images (which is just a reference not a copy) and then change positions in newImages.

That effectively changes the original array, and so when react compares the newImages you pass to setImages with the previous images they are the same array and so, no change is detected.

You can fix it with let newImages = [...images];

Source https://stackoverflow.com/questions/66768998

QUESTION

What does it mean by virtual dom is in-memory?

Asked 2021-Mar-12 at 23:51

I get how virtual-dom batches DOM manipulations to enhance performance. However I have seen some posts saying virtual-dom is fast because it is in-memory representation of actual DOM.

I have read this ANSWER. It says:

on the other hand real DOM has to be accessed from page and loaded to memory for any operation.

does this mean that browser's real DOM is not in memory? If browser's DOM is also in-memory, what makes virtual dom's in-memory special?

...

ANSWER

Answered 2021-Mar-12 at 23:51

Virtual DOM is just a javascript object in memory. While DOM is also mainly in memory (no in disk and on the cloud), it's a complex system with many parts connected.

The difference is that DOM is slow. Manipulating DOM involves many other tasks (https://stackoverflow.com/a/6817110/8810271). Manipulating a virtual DOM without other tasks is no more than a javascript object, which is much faster than element.innerHTML=x.

But remember you still need to manipulate DOM after diffing virtual DOM, to make changes take effect. And it isn't always faster.

Source https://stackoverflow.com/questions/66595934

QUESTION

React Component Lifecycle

Asked 2021-Mar-07 at 21:29

To my knowledge, when some events happen, react creates a virtual-DOM from scratch and compares it to the old virtual-DOM. If that is the case, when the render method is called, react should create components and return them to compare.

...

ANSWER

Answered 2021-Mar-07 at 21:19

The key here is that Demo is not unmounted. When you first render the app, it renders and mounts the Demo component and passes the onChange prop. But, when the callback is invoked from Demo it sets the state on App. Calling setState in App doesn't unmount the Demo component, so there's no need to mount it again. When the component is mounted initially is when the constructor runs. If you had a toggle on the App component that would only show the component within render if a certain condition is true, that would trigger the component to unmount.

Check out this codesandbox and play around a little: https://codesandbox.io/s/lifecycle-methods-vivn6?file=/src/Lifecycle.js.

Also, this is a cool diagram to get a sense of what's happening: https://projects.wojtekmaj.pl/react-lifecycle-methods-diagram/

The main key is that the constructor runs when the component mounts. It will only run again if the component is unMounted from the DOM and then remounted later.

Source https://stackoverflow.com/questions/66521438

QUESTION

esbuild fails without parcel installed

Asked 2020-Oct-24 at 07:17

A project that uses esbuild fails as follows ...

...

ANSWER

Answered 2020-Oct-24 at 07:17

Since the error message says set platform to "node" when building for node, I assume that since you didn't do that this means you are bundling for the browser, not for node. The events package is built in to node but it is not built in to the browser.

It looks like parcel-bundler depends on node-libs-browser which depends on crypto-browserify which depends on events. This explains why installing Parcel fixes this error. If your project needs to depend on the events package (https://www.npmjs.com/package/events), you should install it yourself so it's part of your project:

Source https://stackoverflow.com/questions/64508912

QUESTION

Array list from AsyncData/fetch rendered by v-for throw: The client-side rendered virtual DOM tree is not matching server-rendered

Asked 2020-Oct-12 at 10:48

I am using Nuxt.js for my application. In one of my pages I use AsyncData to asynchronously fetch an array of data objects from my Api, which I render in my template using v-for. This is working fine when I don't use nuxt-link or inside the v-for. As soon as I include nuxt-link or inside my v-for, I get the following error:

...

ANSWER

Answered 2020-Oct-12 at 06:13

Template should only contain 1 element thats fine. But you should not loop the top parent element. Try to wrap it in an div

Source https://stackoverflow.com/questions/64294839

QUESTION

What is it about Vue that enables developers to use the class property on DOM elements?

Asked 2020-Mar-26 at 19:29

JavaScript frameworks like React and Svelte don't allow developers to use the class property on a DOM element because the class keyword is reserved in JavaScript. Meanwhile, other frameworks like Vue somehow get around this.

What is it about how Vue is implemented that makes it possible for Vue developers to use the class keyword on elements? I'd imagine it's something with how Vue converts .vue files to HTML, CSS, and JavaScript but I'm curious about specifics.

Edit: Svelte does not use virtual DOM and you can use the class prop with Svelte.

...

ANSWER

Answered 2020-Mar-11 at 13:28

You can't use class with React because React uses React DOM, which uses camelCase property names, not classical HTML attributes. This is why in JSX (React render language), you have to use className, not class.

Vue is using classical HTML template, so class is allowed.

With Svelte, you should be able to use class keyword in your template.

Source https://stackoverflow.com/questions/60637032

QUESTION

Missing calls in the Chrome devtools js flamechart

Asked 2019-Dec-11 at 21:24

Last time I was doing optimizations (maybe a year ago), I was able to see all possible function calls in the js flamechart.

Now, however, it doesn't seem to go all the way.

Here's a long running function:

I'm expecting way more sub-calls so that I may understand why is it running so long.

Here's how that function looks like:

...

ANSWER

Answered 2019-Dec-11 at 21:24

The Performance panel has a Disable JavaScript Samples checkbox in the capture settings menu.

When this checkbox is enabled, the timeline only shows the yellow placeholders to differentiate between script execution time and, layout, paint and composite activity. Notice how the Cog/Settings Icon is red when the checkbox is enabled.

When the checkbox is not checked, the timeline shows the flame chart. When all the capture options are in their default state, the Cog/Settings Icon is blue while the menu is open and grey when the menu is closed/collaped.

Unfortunately it is not possible to be certain that this was the exact issue that you encountered, as the shared screenshot doesn't depict the capture settings. Hopefully this knowledge proves valuable should you encounter the same behaviour in the future.

Source https://stackoverflow.com/questions/57230279

QUESTION

Error on installing NoRedInk/elm-decode-pipeline with Elm 0.19.1

Asked 2019-Nov-27 at 20:14

I'm working through an example on elmprogramming.com and am stuck on installing the elm-decode-pipeline package. Specifically when I

...

ANSWER

Answered 2019-Nov-27 at 20:14

It's just moved. The package is now at NoRedInk/elm-json-decode-pipeline.

You definitely can't be blamed for being confused though. There is no indication of this in the package documentation, only in the description of the source code repository, and there's also no indication that the old package only works with 0.18. Unfortunately this is just the state of the package ecosystem at the moment, and fixing it does not seem to have much priority.

The best way to make sure you have a package that works for 0.19 is to search for it on the package site. Everything that pops up there should work for 0.19, as you have to use a different search for 0.18 packages.

Source https://stackoverflow.com/questions/59077733

QUESTION

ReactJS virtual DOM in memory and applying incremental changes

Asked 2019-Oct-08 at 20:13

Came across below statement in one or other form on google

Each time the underlying data changes in a React app, a new Virtual DOM representation of the user interface is created.This is where things get interesting. Updating the browser’s DOM is a three-step process in React.

Whenever anything may have changed, the entire UI will be re-rendered in a Virtual DOM representation.

The difference between the previous Virtual DOM representation and the new one will be calculated.

The real DOM will be updated with what has actually changed. This is very much like applying a patch.

I am new to React and would like to understand above how above three points used to to work in pre-React Era say in jQuery (or native JS).

jQuery

HTML was constructed on server side, sent back to browser. Browser will parse, render, layout and paint it.
Say any new DOM element is created or hidden either on some user event or on load.
Will jQuery recreate the complete DOM? From third point stated above looks like React just update the DOM for only the part that has been changed but other system (primarily jQuery or native JS) will recreate the complete DOM. Is that correct?
Is the third point true only for DOM changes or even when state of any UI component changes like filling the text box/dropdown etc?

...

ANSWER

Answered 2019-Oct-08 at 20:11

Will jquery recreate the complete DOM ? From third point stated above looks like React just update the DOM for only the part that has been changed but other system(primarily jquery or native js) will recreate the complete DOM. Is that correct?

jQuery

No, jQuery doesn't recreate the DOM. Instead it navigates the DOM tree with selectors provided to make the appropriate changes. This makes jQuery very similar to React, but its performance issues come with the way the code was designed and it's heavy usage of the facade design pattern. This is normal for any larger library that needs to support multiple browsers like Chrome, Firefox, Opera, etc.

Angular 1

A framework that used to repaint the entire DOM was Angular 1. The client would make some changes, and rerender whenever $scope.apply or $scope.digest was called. This, combined with a huge number of listeners on large pages for two way data-binding was one of the big reasons why Angular had to undergo significant changes to stay competitive. Angular 8 is probably equivalent to React, but one has seen more adoption then the other.

React

React only updates the DOM that was changed. This is part of its "secret sauce". Along with its component centric architecture and early adoption of one way data-binding, it's seen a lot of success. Arguably React is starting to get more bloated since there's such wide adoption. This is normal for any project that gets mainstream usage. It's only a matter of time until people view React as a ton of performance problems and we'll create a new framework.

Alternatives

There are even faster frameworks than React, such as Elm lang. Nothing ever beats pure Javascript (e.g. document.querySelector()) since at their core, all frameworks use it. At that point you start hitting other trade offs such as lack of external libraries you can depend on, or difficulty in maintaining large front end codebases.

Is the third point true only for dom changes or even when state of any UI component changes like filling the text box/drop down etc ?

For jQuery or pure JS the third point is not true. There's a custom on-click handler of some sort that will run a function that makes a small change.

For something like Angular, that could be true if there are changes to scope that trigger a repaint. The same applies for React. If your submit button is supposed to redirect you to a completely different page, it will basically be repainting the DOM.

Source https://stackoverflow.com/questions/58290139

QUESTION

How to create your own babel processor alternative to `React`

Asked 2019-Jul-20 at 15:28

When you use JSX in a JS file, you have to import React or else the generated code won't compile. This is because this:

...

ANSWER

Answered 2019-Jul-20 at 15:28

The Babel plugin responsible for JSX processing is @babel/plugin-transform-react-jsx. Despite its React-specific name, you can use any pragma you like (React.createElement is the default pragma) by setting an option in your .babelrc file:

Source https://stackoverflow.com/questions/57125908

Community Discussions, Code Snippets contain sources that include Stack Exchange Network

Vulnerabilities

No vulnerabilities reported

Install virtual-dom

You can download it from GitHub.

Support

For any new features, suggestions and bugs create an issue on GitHub. If you have any questions check and ask questions on community page Stack Overflow .

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