preview and remove image before upload reactjs code example
Example: multiple image upload with preview and delete react js
import React, { Component } from 'react';import { Icon, Button, Image } from "semantic-ui-react";import Compress from "compress.js";// It renders "<" icon, on clicking it gets the earlier photo.const BackArrow = (props) => ( <div onClick={props.previousImage} style={{cursor: "contextMenu", color: "white", fontSize: '2em', marginRight: "-38px", zIndex: 1}}> <Icon name="angle left" /> </div>);// It renders ">" icon, on clicking it gets the next photo.const NextArrow = (props) => ( <div onClick={props.nextImage} style={{color: "white", fontSize: '2em', marginLeft: "-38px", zIndex: 1}}> <Icon name="angle right" /> </div>);class ImageUploader extends Component { state = { pictures: [], // to store the pictures in base64 format. slideCount: 0 //to keep track of the photo number }nextImage = () => { let { slideCount } = this.state; if(slideCount !== this.state.pictures.length - 1) { slideCount = slideCount + 1; } this.setState({ slideCount }); }previousImage = () => { let { slideCount } = this.state; if(slideCount !== 0) { slideCount = slideCount - 1; } this.setState({ slideCount }); }handleImageChange = e => { e.preventDefault();// Getting multiple images from user's selection for (var i = 0; i < e.target.files.length; i++) { let file = e.target.files[i]; // console.log(file); if(!file.type.includes('image')) { alert('Please choose image'); } else if(file.size / (1024*1024) > 5) { alert('Please choose image of smaller size'); } } const compress = new Compress(); const files = [...e.target.files]; compress.compress(files, { size: 4, quality: 0.75, maxWidth: 1920, maxHeight: 1920, resize: true }).then(modFiles => { // modFiles are modified files with exif free and compressed // versions of user selected images let uploadableFiles = []; for (var i = modFiles.length - 1; i >= 0; i--) { let file = Compress.convertBase64ToFile(modFiles[i].data, modFiles[i].ext); let filename = Date.now() + modFiles[i].alt; let filetype = modFiles[i].ext; let filelastMod = files[i].lastModified; uploadableFiles.push(new File([file], filename, {type: filetype, lastModified: filelastMod})); } let img = new Image(); let obj; img.onload = () => { obj = { width: img.width, height: img.height }; this.setState({ pictures: [ ...this.state.pictures, obj ] }); } img.src = modFiles[i].prefix + modFiles[i].data; }); }render() { const { pictures, slideCount } = this.state;return ( <div> { pictures.length > 0 ? ( <div> {pictures.map((photo, key) => { if (pictures.indexOf(photo) === slideCount) { return ( <div style={{display: 'flex', alignItems: 'center', justifyContent: 'center'}}> {slideCount !== 0 ? <BackArrow previousImage={this.previousImage}/> : ''} <div id="imageid" key={photo.id} style={{margin: '0 auto'}}> <Image src={photo.src} alt='photo'/> { pictures.length > 1 && ( <div style={{zIndex: 2}}> {slideCount+1} of {pictures.length} </div> )} </div> {slideCount !== (pictures.length - 1) ? <NextArrow nextImage={this.nextImage}/> : ''} </div> ) } return '' })} <div style={{ padding: "5px" }}> <Button color="grey" icon="close" circular basic content="clear pictures" onClick={this.handleClearImages} /> </div> </div> ) : ( <div> <label htmlFor="upload-photo"> /* An image is shown instead of input type="file" button. When user clicks on it, he can select the images from his gadget. */ <img alt="upload images" src={"https://via.placeholder.com/512.png?text=Upload+images"} /> </label> <input style={{ opacity: 0, zIndex: 1 }} id="upload-photo" type="file" multiple={true} onChange={this.handleImageChange} /> </div> ) } </div> ); }}export default ImageUploader;