To start building a user interface, you might use React, a JavaScript library for building flexible and reusable components. However, you also need a supporting tool for managing digital media (images and videos). The recently announced React SDK from Cloudinary capably serves that purpose.

In brief, the Cloudinary platform enables you to seamlessly and efficiently upload, optimize, transform, store, and deliver media across viewing devices with no quality compromise. Do check out its many feature-rich, sound capabilities.

This tutorial guides you through the steps of building a React image gallery with Cloudinary’s React SDK. It’s an intuitive, straightforward process well worth learning.

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First, install Cloudinary’s React SDK and upload widget:

Create a file with the following JSON code to specify the basic properties for the React app and configure a minimal number of its dependencies.

Copy to clipboard { " name " : " img-library " , " version " : " 1.0.0 " , " description " : " " , " main " : " index.js " , " scripts " : { " watch " : " webpack -d --watch " , " build " : " webpack " , " serve " : " serve ./public " }, " author " : " " , " license " : " MIT " , " devDependencies " : { " babel-core " : " ^6.18.2 " , " babel-loader " : " ^6.2.9 " , " babel-preset-es2015 " : " ^6.18.0 " , " babel-preset-react " : " ^6.16.0 " , " serve " : " ^1.4.0 " , " webpack " : " ^1.14.0 " }, " dependencies " : { " axios " : " ^0.15.3 " , " cloudinary-react " : " ^1.0.1 " , " react " : " ^15.4.1 " , " react-dom " : " ^15.4.1 " } }

Note Under dependencies : axios is a tool for making HTTP requests, in this case for the images on the Cloudinary server.

is a tool for making HTTP requests, in this case for the images on the Cloudinary server. cloudinary-react refers to Cloudinary's React SDK.

refers to Cloudinary's React SDK. react is the React library.

is the React library. react-dom is the React Document Object Model (DOM). Under

Install the dependencies with this npm command line:

Copy to clipboard # Install dependencies npm install

Webpack is the build tool. Create a file with the following JavaScript code to configure the basic Webpack settings, such as the entry, output, and loaders, for running builds and compiling React apps ( .jsx files).

Copy to clipboard var webpack = require( ' webpack ' ); var path = require( ' path ' ); var BUILD_DIR = path.resolve(__dirname, ' public ' ); var APP_DIR = path.resolve(__dirname, ' src ' ); var config = { entry : APP_DIR + ' /index.jsx ' , output : { path : BUILD_DIR, filename : ' bundle.js ' }, module : { loaders : [ { test : / \. jsx? / , include : APP_DIR, loader : ' babel ' } ] } }; module.exports = config;

Create the two files below. The top one, which is in JavaScript ( index.jsx ), generates an entry point similar to the one configured for Webpack. The bottom one, which is in HTML ( index.html ), creates an entry point for the browser.

Copy to clipboard import React, { Component } from ' react ' ; import { render } from ' react-dom ' ; class Main extends Component { render() { return ( <div className = " main " > <h1> Scotchage </h1> </div> ); } } render(<Main />, document.getElementById( ' container ' ));

Copy to clipboard <html> <head> <link rel = " stylesheet " href = " style.css " > <meta name = " viewport " content = " width=device-width, initial-scale=1 " > </head> <body> <div id = " container " > </div> <script src = " bundle.js " > </script> </body> </html>

Sign up for a free Cloudinary account. Afterwards, your credentials are displayed on your account dashboard, as in this example:

Upload your React app’s images to Cloudinary with the latter’s upload widget. Do the following:

Add the upload widget to the React app’s index.html file: Copy to clipboard Create a button, attach an event to it, and upload an image on a click of the button. Here’s the JavaScript code: Copy to clipboard import React, { Component } from ' react ' ; import { render } from ' react-dom ' ; class Main extends Component { uploadWidget() { cloudinary.openUploadWidget({ cloud_name : ' cloud_name ' , upload_preset : ' preset ' , tags :[ ' xmas ' ]}, function (error, result) { console.log(result); }); } render(){ return ( <div className = " main " > <h1> Galleria </h1> <div className = " upload " > <button onClick = { this.uploadWidget.bind ( this ) } className = " upload-button " > Add Image </button> </div> < / div> ); } } render(<Main / >, document.getElementById( ' container ' ));

Note The uploadWidget member method is the handler invoked by the click event to upload images by calling cloudinary.openUploadWidget .

member method is the handler invoked by the click event to upload images by calling . openUploadWidget takes as its parameters a configuration object and the upload callback handler. Be sure to specify the valid values for the cloud_name and upload_preset properties. For details, see the documentation on cloud names and upload presets.

The Cloudinary React SDK comprises three major components:

Image : This component requests for the images defined by their IDs from the Cloudinary server and then displays the images on the browser.

: This component requests for the images defined by their IDs from the Cloudinary server and then displays the images on the browser. Transformation : This component transforms the images delivered with Image .

: This component transforms the images delivered with . CloudinaryContext: Configuring multiple images, one by one, in the Image component is tedious. Instead, you can specify the configuration for them all in this component.

Here’s a typical structure:

Copy to clipboard <CloudinaryContext> <Image> <Transformation /> <Transformation /> </Image> <Image> <Transformation /> </Image> </CloudinaryContext>

Now request an image from the Cloudinary server and display the image with certain components through this JavaScript code:

Copy to clipboard import React, { Component } from ' react ' ; import axios from ' axios ' ; import { CloudinaryContext, Transformation, Image } from ' cloudinary-react ' ; import { render } from ' react-dom ' ; class Main extends Component { constructor(props) { super (props); this .state = { gallery : [] } } componentDidMount() { axios.get( ' https://res.cloudinary.com/christekh/image/list/xmas.json ' ) .then(res => { console.log(res.data.resources); this .setState({ gallery : res.data.resources}); }); } uploadWidget() { } render(){ return ( <div className = " main " > <h1> Galleria </h1> <div className = " gallery " > <CloudinaryContext cloudName = " cloud_name " > { this.state.gallery.map(data = > { return ( <div className = " responsive " key = { data.public_id } > <div className = " img " > <a target = " _blank " href = { ` https: / / res.cloudinary.com / christekh / image / upload / $ { data.public_id } .jpg ` } > <Image publicId = { data.public_id } > <Transformation crop = " scale " width = " 300 " height = " 200 " dpr = " auto " responsive_placeholder = " blank " /> </Image> </a> <div className = " desc " > Created at {data.created_at} </div> < / div> < / div> ) }) } < / CloudinaryContext> <div className="clearfix">< / div> < / div> < / div> ); } } render(<Main />, document.getElementById( ' container ' ));

The upload code reads like this:

Copy to clipboard cloudinary.openUploadWidget({ cloud_name : ' christekh ' , upload_preset : ' idcidr0h ' , tags :[ ' xmas ' ]}, function (error, result) { . . .

Here, you’re requesting a collection of images, all tagged with xmas . That is exactly what the axios library does when the component mounts:

Copy to clipboard axios.get( ' https://res.cloudinary.com/cloud_name/image/list/xmas.json ' ) .then(res => { console.log(res.data.resources); this .setState({ gallery : res.data.resources}); });

axios operates on promises. Whenever a promise is resolved in the React app, a collection of images become available for UI updates through React state.

To render the images, configure the CloudinaryContext with the value of cloud_name , iterate over the gallery state, which stores the images, and displays them through the Image component. Separately, apply the transformations that you desire for the images with the Transformation component.

Note For security, you cannot request images from the client. Instead, request them with Cloudinary’s Admin API through a backend SDK and then send the resource list to the client. See the For security, you cannot request images from the client. Instead, request them with Cloudinary’s Admin API through a backend SDK and then send the resource list to the client. See the related documentation for details.

Leverage the code below to instantly update the displayed images with the new ones uploaded by the user:

Copy to clipboard uploadWidget() { let _this = this ; cloudinary.openUploadWidget({ cloud_name : ' cloud_name ' , upload_preset : ' preset ' , tags :[ ' xmas ' ]}, function (error, result) { _this.setState({ gallery : _this.state.gallery.concat(result)}) }); }

Rather than passing the image information to the Cloudinary console, the above code updates the gallery state with its list of the requested images by concatenating the uploaded result to gallery .

A React image gallery is as a handy trove for web projects. Thanks to Cloudinary’s React SDK, building it is a chore-free task.

Cloudinary provides easy-to-use, cloud-based media management solutions for the world’s top brands. With offices in the US, UK and Israel, Cloudinary has quickly become the de facto solution used by developers and marketers at major companies around the world to streamline rich media management and deliver optimal end-user experiences.

For more information, visit www.cloudinary.com or follow us on Twitter.