uploadcare-nextjs-loader1 v0.1.0

In Development Uploadcare custom image loader for Next.js

!!! Please note the project is in active development and it's not ready for production just yet.

• Demo
• Preview
• Dependencies
• Installation
• Configuration
• Usage
• Links
• Known Issues

Demo

Look at the demo here.

Preview

Preview it on StackBlitz:

Dependencies

Next.js supports custom image loaders starting from 10.0.5.

Installation

yarn add nextjs-loader

Configuration

Inform Next that you're going to use a custom image loader through next.config.js:

// next.config.js
module.exports = {
  images: {
    loader: "custom"
  }
}

Add your public Uploadcare key to your .env* config file. You can copy it from Dashboard -> API Keys -> Public key.

#.env
NEXT_PUBLIC_UPLOADCARE_PUBLIC_KEY="YOUR_PUBLIC_KEY"

Alternatively, in case you're using a custom proxy, set the proxy domain.

#.env
NEXT_PUBLIC_UPLOADCARE_CUSTOM_PROXY_DOMAIN="proxy.example.com"

That's it. You may now use nextjs-loader in your project (see Usage).

Below are additional optional parameters which you may not need:

#.env
# A comma-separated list of transformation parameters. Default: format/auto, stretch/off, progressive/yes
NEXT_PUBLIC_UPLOADCARE_TRANSFORMATION_PARAMETERS="format/auto, stretch/off, progressive/yes"
# Uploadcare CDN domain. Default: ucarecdn.com
NEXT_PUBLIC_UPLOADCARE_CUSTOM_CDN_DOMAIN="cdn.example.com"

Please note NEXT_PUBLIC_UPLOADCARE_TRANSFORMATION_PARAMETERS override corresponding default parameters and keep others in place.

Usage

Option 1. Use the UploadcareImage component and leave us the reset ;)

import UploadcareImage from 'nextjs-loader';

<UploadcareImage
  alt="A test image"
  src="https://your-domain/image.jpg"
  width="400"
  height="300"
  quality="80"
/>

The UploadcareImage component supports the same parameters as the Next Image component.

Option 2. Pass uploadcareLoader to the Image component:

import Image from 'next/image';
import { uploadcareLoader } from 'nextjs-loader';

<Image 
  alt="A test image"
  src="https://your-domain/image.jpg"
  width="400"
  height="300"
  quality="80"
  loader={uploadcareLoader}
/>

Option 3. Use next-image-loader project to enable Uploadcare image loader for all images by default

In that case, you may not need the loader: "custom" setting in your next.config.js.

1. Install the next-image-loader plugin and enable it as described in its README.

2. Create image-loader.config.js in the project root (in the same directory as next.config.js) and add this code to it:

// image-loader.config.js
import { imageLoader } from 'next-image-loader/build/image-loader';
import { uploadcareLoader } from 'nextjs-loader';

imageLoader.loader = uploadcareLoader;

3. Use Image as usual, with Uploadcare loader enabled implicitly:

import Image from 'next/image';

<Image 
  alt="A test image"
  src="https://your-domain/image.jpg"
  width="400"
  height="300"
  quality="80"
/>

Please note that you can still use any other loader for a separate image like this:

import Image from 'next/image';
import anotherLoader from '[another-loader-project-name]';

<Image 
  alt="A test image"
  src="https://your-domain/image.jpg"
  width="400"
  height="300"
  quality="80"
  loader={anotherLoader}
/>

where anotherLoader will be used instead of the Uploadcare loader for this particular image.

Links

• Uploadcare image compression documentation
• Uploadcare File Uploader for React

Known Issues

Issue 1: Console warning like this:

Image with src "${src}" has a "loader" property that does not implement width. Please implement it or use the "unoptimized" property instead. Read more: https://nextjs.org/docs/messages/next-image-missing-loader-width

Next checks whether the image url which loader generates has the exact value which user passed through the width property of the Image component. And because the Uploadcare loader doesn't process SVG and GIF images, it just returns the same src value without adding any transformation parameters to it (including width). That's why Next reports the console warning.

Fix: Ignore the warning for now.