joppot

コピペで絶対動く。説明を妥協しない

プログラミング

Tutorial How to use GSAP animation with React

投稿日:2018年11月19日 更新日:


Abstract

Hello everyone it’s me candle. In this time we will use GSAP in React.
The famous js library which can easily use animation is jQuery.
However, it seems that compatibility between jQuery and React is bad.
And there are no functions
Also, as far as I know, React has no animation function that is easy to use(Yeah, Transition is).

But, all times and places, it is rare case that animation is not necessary when you have created a web service. There are many candidates when using animation with React.

Of course, you can import only the necessary functions and use them in minimum usage. Let’s try it.

This article uses a tutorial format.

Condition

  1. You have a React knowledge

Preparation

Create a new project. execute the command in the terminal.

create-react-app react-animation
cd react-animation

We will edit thesrc/App.js like this.

import React, { Component } from 'react'
import './App.css'

class App extends Component {
  render() {
    return (
      <div className="App">
        <header className="App-header">
          <div>hello</div>
        </header>
      </div>
    )
  }
}

export default App

Next you edit src/App.css.

.App {
  text-align: center;
}

.App-header {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  font-size: calc(10px + 2vmin);
}

Install GSAP

We need two libraries gsap and react-gsap-enhancer to use gsap in React.
Install it this command.

yarn add gsap react-gsap-enhancer

Run animation only once

You should change writing code either a component that runs animation only once or more than once. First we will make a component that runs animation only once when it is mounted.

Make a src/componets folder.

mkdir src/components

Create a OneTimeCard component file.

touch src/components/OneTimeCard.js

The code is this.

import React from 'react'
import GSAP from 'react-gsap-enhancer'
import { TimelineMax } from 'gsap'

class OneTimeCard extends React.Component {
  constructor(props) {
    super(props)
    this.myCard = null
  }

  componentDidMount() {
    new TimelineMax().from(this.myCard, 1, { y: 20, opacity: 0 })
  }

  render() {
    return (
      <div>
        <div style={styles.box} ref={div => (this.myCard = div)}>
          <div>Card</div>
        </div>
      </div>
    )
  }
}

const styles = {
  box: {
    width: '120px',
    height: '120px',
    zIndex: 1,
    cursor: 'pointer',
    border: '1px solid black',
    display: 'flex',
    justifyContent: 'center',
    alignItems: 'center',
  },
}

export default GSAP()(OneTimeCard)

The most important part is here in these codes.

componentDidMount() {
  new TimelineMax().from(this.myCard, 1, { y: 20, opacity: 0 })
}

Display it with transparency 0 to 1 and moving 20px on the y axis in 1 second.

Open the src/App.js and edit like this.

import React, { Component } from 'react'
import OneTimeCard from './components/OneTimeCard'
import './App.css'

class App extends Component {
  constructor(props) {
    super(props)
  }

  render() {
    return (
      <div className="App">
        <header className="App-header">
          <OneTimeCard />
        </header>
      </div>
    )
  }
}

export default App

When launch the server and check it, You will see the card drifting from below.

yarn run start

Run an animation more than two times

Well, let’s try to create a more elaborate animation component this time.

Let’s create a component where the card appears with the animation when the button is pushed and the card disappears when the button is pushed again

Create a new SwitchingCard.js file.

touch src/components/SwitchingCard.js

The content like this.

import React from 'react'
import GSAP from 'react-gsap-enhancer'
import { TimelineMax } from 'gsap'

class SwitchingCard extends React.Component {
  constructor(props) {
    super(props)
    this.state = {
      isBox: false,
    }
    this.myElement = null
    this.myTween = new TimelineMax()
  }

  toggleBox() {
    if (!this.state.isBox) {
      this.addAnimation(this.createAnim.bind(this))
    } else {
      this.addAnimation(this.createExitAnim.bind(this))
    }

    this.setState(prevState => ({
      isBox: !prevState.isBox,
    }))
  }

  createAnim() {
    return this.myTween
      .to(this.myElement, 0.1, { display: 'flex', clearProps: 'transform' })
      .to(this.myElement, 1, { y: 10, opacity: 1 })
  }

  createExitAnim() {
    return this.myTween
    .to(this.myElement, 1, { y: -1, opacity: 0 })
    .to(this.myElement, 0, { display: 'none' })
  }

  render() {
    const { isBox } = this.state
    return (
      <div style={styles.wrapper}>
        <div onClick={this.toggleBox.bind(this)} style={styles.button}>
          Show
        </div>

        <div style={styles.box} ref={div => (this.myElement = div)}>
          <div>Card</div>
        </div>
      </div>
    )
  }
}

const styles = {
  wrapper: {
    position: 'relative',
  },
  button: {
    width: '110px',
    cursor: 'pointer',
    border: '1px solid black',
    padding: '5px 5px',
  },
  box: {
    position: 'absolute',
    bottom: '55px',
    width: '120px',
    height: '120px',
    zIndex: 1,
    cursor: 'pointer',
    border: '1px solid black',
    display: 'none',
    justifyContent: 'center',
    alignItems: 'center',
    opacity: 0,
  },
}

export default GSAP()(SwitchingCard)

Open the src/App.js, change the component to use.

import './App.css'
import React, { Component } from 'react'
import SwitchingCard from './components/SwitchingCard'

class App extends Component {
  constructor(props) {
    super(props)
  }

  render() {
    return (
      <div className="App">
        <header className="App-header">
          <SwitchingCard />
        </header>
      </div>
    )
  }
}

export default App

Before code explanation run it.
How is it ? You can confirm that you push the button then a card appears and push it again then it disappears.

I will explain what it is.

Manage animated target DOM with ref

Specify animation targets with React’s refs. Initializing the variable this.myElement = null which assigns the target DOM in the constructor ().

Define the target of refs in JSX.

<div style={styles.box} ref={div => (this.myElement = div)}>
  <div>Card</div>
</div>

By the way, React.createRef() introduced in React 16.x could not be used.

Recycle a instance of animation

Instead of creating instances of TimelineMax () each time you write an animation over and over, we create and reuse the this.myTween = new TimelineMax () instance in constructor ().

It has been used in the createAnim() function and the createExitAnim() function.

 createAnim() {
    return this.myTween
      .to(this.myElement, 0.1, { display: 'flex', clearProps: 'transform' })
      .to(this.myElement, 1, { y: 10, opacity: 1 })
  }

  createExitAnim() {
    return this.myTween.to(this.myElement, 1, { y: -1, opacity: 0 }).to(this.myElement, 0, { display: 'none' })
  }

Add continuous animation to GSAP

If animation continues more than once, you need to use this.addAnimation () of react-gsap-enhancer.

This is because the animation needs to take over the movements of the previous animation instead of moving independently of each other.

Your created animation was added to GSAP at the part.

   if (!this.state.isBox) {
      this.addAnimation(this.createAnim.bind(this))
    } else {
      this.addAnimation(this.createExitAnim.bind(this))
    }

If you change this part as shown below and execute it directly, the animation of the createAnim () and the animation of createExitAnim () are executed separately.

 if (!this.state.isBox) {
   this.createAnim()
 } else {
   this.createExitAnim()
 }

You must add the function of continuous animation to addAnimation.

Conclusion

We tried animation using GSAP with React. GSAP is the animation library with a very large volume, so please check yourself and try implementing.

It is a good idea to read the GSAP official Getting started and react parts once.

Getting Started with GSAP

https://greensock.com/get-started-js

Getting Started: React and GSAP Animations

https://greensock.com/react

スポンサードリンク

If you think this article is good, share it please

-プログラミング
-, ,

執筆者:


comment

Your email address will not be published. Required fields are marked *

関連記事

Lazy load image with react-lazyload

Abstract Hello everyoen it’s me candle. This time let’s make a delayed loading of images with react-lazyload. The problem of SPA is the delay at the time of initial loading. Among them, we feel that the site with many images is even late. Let’s try it. Condition Nothing Prepare If you have already developing react project, use it. But you don’t have yet or try to test. Generate it with this command. create-react-app imageloader-sample cd imageloader-sample We will prepare images for samples with Faker.js, so install it. yarn add faker Ready to develop. Make a sample code Open the src/App.js …

Create plantUML with emacs using plantuml-mode

Autumn leaves on wood table Abstract Hello everyone it’s me candle. In this time, we will introduce plantuml-mode of emacs supporting plantUML. plantuml-mode has three functions. Syntax highlight Autocomplete Display UML preview There are plenty of settings, so let’s do it patiently. Precondition You had plantuml command I installed plantuml with brew. but it is ok you prepare jar file. If you don’t have it yet, please refer to here. Build PlantUML environment on Mac using brew Install plantuml-mode The latest version of plant-mode is not yet registered in el-get packages, so we will get it from github directly. For …

Create the simplest drop down menu in React

Abstract Hello everyone it’s me candle. In this time we will make a most simple drop down menu. Condition Knowledge of react Preparation We create a react project with the below command. create-react-app hello-menu Open src/App.js and write this. import React, { Component } from 'react' class App extends Component { render() { return ( <div> <p>hello menu</p> </div> ) } } export default App Create a components directory in the src directory. mkdir src/components Create a DropDownMenu.js file in the src/components directory. touch src/components/DropDownMenu.js Now on ready. Create a Drop down menu Open the src/components/DropDownMenu.js and write these. import …

Deploy React to s3 with aws command

Abstract Hello veryone it’s me candle. In this time I will show you how to deploy a react project created by create-react-app to S3. A good thing about React web app is that you can publish the products created by building them as long as you upload them such as html and js files and images to storage. In this article I don’t write these three items. How to get a IAM that can access to S3 Allocate your own domain using Route53 SSL connection of React web app Condition You have aws command Please install the aws command in …

React creates dummy data using Faker.js

Abstract Hello everyone it’s me candle. Let’s try to use Faker.js in React. I think that there are various purposes for using Faker.js. In many cases you will use it for testing, but this time I’d like to create a dummy react state using Faker.js. Condition You have a basic react skill create-react-app was installed Create new project First of all, create a react project. Execute the below command in your favorite directory and create a new react project. create-react-app faker-demo cd faker-demo Installation of faker Install faker with this coommand. yarn add –dev faker it’s over. Generate dummy data …


I work in the venture company as a CTO. I start to write program in University, first I learned java, C++ and PHP. In the company, I'm developing web services by Rails. I do like to automation.