Define a function called handleFileInputChange that is called when the user selects an image file.In the component’s state, define a image variable that will store the selected image, and a cropper variable that will store the instance of the CropperJS class.Define a functional component called ImageUpload that renders an input element of type “file” and a CropperJS instance.Import the React and useState hooks from the react library, and import the Cropper class and its stylesheet from the cropperjs library.Here’s a summary of the ImageUpload.js component code: enable(): This method enables the cropping functionality of the CropperJS instance.īy using these methods, you can manipulate the canvas element generated by CropperJS in various ways, such as setting its dimensions, exporting it as an image, or replacing the original image with a new one.Ĭonst = useState(null) įileReader.readAsDataURL(e.target.files) Ĭonst canvas = cropper.getCroppedCanvas().disable(): This method disables the cropping functionality of the CropperJS instance.The canvas element is updated with the new image. replace(url): This method replaces the current image with a new image specified by the url parameter.clear(): This method clears the canvas element.The data parameter should be an object that contains the following properties: left, top, width, and height. setCropBoxData(data): This method sets the data for the crop box.The data parameter should be an object that contains the following properties: left, top, width, height, naturalWidth, and naturalHeight. setCanvasData(data): This method sets the data for the canvas element.getCroppedCanvas(options): This method allows you to specify additional options for the cropped canvas, such as the output type ( jpeg or png), the output quality (0 to 1), and whether to include the original image’s metadata in the output.
You can specify options such as the output size, format, and quality of the cropped canvas. getCroppedCanvas(): This method returns a canvas element that contains the cropped portion of the original image.Here are some of the main canvas-related methods provided by CropperJS:
React image file resizer example install#
To run the React app, execute the following command on your terminal: npm startĬheck out your React app on this URL: localhost:3000 Step 2 – Install React Image Crop PackageĮxecute the following command to install react image crop dependencies into your react app: npm install cropperjs canvas -saveĬropperJS is a JavaScript library for cropping images, and it provides several methods for working with the cropped image as a canvas element. In this step, open your terminal and execute the following command on your terminal to create a new react app: npx create-react-app my-react-app
React image file resizer example how to#
A text editor such as VS Code or Sublime Text How to Resize Image Before Upload in React jsįollow the following steps and resize, crop, and compress images before uploading in react js app:.Node.js and npm installed on your computer.Basic knowledge of ReactJS and JavaScript.We will also use the HTML5 canvas element to resize the image.īefore you begin, make sure you have the following:
You will be using the ReactJS library, along with the popular image processing library called CropperJS. This will be useful if you need to reduce the size of images to save storage space or if you want to improve the user experience by reducing the upload time. React resize, crop & compress images before upload In this tutorial, you will learn how to use ReactJS to resize, crop, and compress images before uploading them to your server.
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