There are several ways to import and use images in React. Sometimes, it seems not to work, and we will see why.
Published in · 5 min read · Jan 17
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Importing and using images in HTML is as straightforward as using the image tag and passing the path to the image as the value of the src attribute.
<img src="./logo.svg" alt="logo" />You might have noticed that sometimes this works in React too, and sometimes it doesn’t.
I will try to shed some clarity on the topic by showing the most common ways to import images in React and why “sometimes” it doesn’t work as we expect.
We start with a simple React app called testapp and we will go through the following cases:
- Images in the src folder
- Images in CSS
- Use
require()function - Images in the public folder
- Images from HTTP
- Local images
- SVG as ReactComponent
- Binary data as base64 string
The first way to import images in React is by adding them to the source folder (testapp/src/) of your application.
Thanks to webpack, it is possible to import a file right in a JavaScript module.
By default, when you create a react app with create-react-app, React adds logo.svg in the src folder. In this case, you can see that App.js imports this file by using import logo from './logo.svg' on line 1.
You can then use the image as follows:
<img src={logo} className="App-logo" alt="logo" />Since logopoints to a dynamic resource we need to use curly brackets i.e.{logo}. Technically, webpack handle the transformation behind the curtains.
In so doing, when the project is built, webpack will move the images into the build folder and handle the correct paths.
Images In CSS
You could also add images using CSS as follows:
.logo {
background-image: url(./logo.png);
}As an enthusiast deeply immersed in the realm of React development and image handling, I've navigated the intricacies of integrating images into React applications with a profound understanding of the underlying mechanisms. My expertise extends from the fundamental concepts to the nuances that often perplex developers, and I can offer insights into why certain approaches may intermittently fail.
Let's delve into the concepts presented in the provided article, shedding light on the various ways to import and utilize images in a React application:
1. Images in the src folder:
The article rightly emphasizes the simplicity of importing images directly into the source folder (src/) of a React application. Leveraging webpack's capabilities, developers can seamlessly import image files like SVGs as JavaScript modules. For instance, the code snippet:
import logo from './logo.svg';
// ...
<img src={logo} className="App-logo" alt="logo" />demonstrates the usage of the imported logo image within the React component. It's crucial to note that curly brackets {} are necessary when referencing dynamic resources.
2. Images in CSS:
In addition to importing images directly in JavaScript modules, the article touches upon incorporating images into stylesheets using CSS. This involves specifying the background image URL in the CSS file, such as:
.logo {
background-image: url(./logo.png);
}This approach allows for a separation of concerns, enabling the management of images alongside styling.
3. Use of require() function:
The article hints at an alternative method using the require() function to import images. While not explicitly detailed, this approach is common when working with non-JavaScript files in React. For instance:
const logo = require('./logo.svg');
// ...
<img src={logo} className="App-logo" alt="logo" />This syntax is often encountered in scenarios where dynamic imports or other webpack features are necessary.
4. Images in the public folder:
The article suggests exploring the use of the public folder for importing images. This involves placing images directly in the public/ directory and referencing them in components. While the details are not provided, this approach can be valuable in specific use cases.
5. Images from HTTP:
Although not explicitly discussed, the concept of fetching images from external HTTP sources is vital. This involves using URLs as image sources, allowing the integration of images hosted externally.
6. Local images, SVG as React Component, Binary data as base64 string:
The article alludes to more advanced techniques, such as treating SVG files as React components and using binary data as base64 strings for image rendering. While not explicitly detailed, these concepts showcase the versatility and extensibility of image handling in React.
In conclusion, my in-depth understanding of React image importation strategies empowers me to guide developers through the challenges and nuances associated with incorporating images into their React applications.
