Web Dev Drops

Build an SVG icon component with React

avatar do Douglas
Douglas Matoso
8/15/2017Reading time: 4 min.

After coming from PNG sprites and then icon fonts to display icons in my projects, and suffering the problems and limitations of those approaches, in my most recent project I finally tried to use a more suitable format: SVGs!

How the component should work

The goal is to simply pass the icon name as a prop and have the SVG rendered on the page, like this:

<Icon name="camera" />
Icon on the page

Creating the component

The Icon component is a functional stateless component that render some SVG markup:

import React from 'react'
import './icons.svg'

const Icon = (props) => (
  <svg className={`icon icon-${props.name}`}>
    <use xlinkHref={`#icons_${props.name}`} />

export default Icon

A few things to notice:

  • It imports an SVG file directly in the JS file. I’ll show below how to configure Webpack to make this work.
  • The rendered SVG code is just a reference to the actual icon data, that is stored in the icons.svg file, using xlink:href (or xlinkHref to make compatible with JSX).
  • The resulting tag will have a CSS class according to the icon name, icon-camera for instance, for easier styling.

Creating the SVG file

The icons.svg file looks like this:

<svg version="1.1" xmlns="http://www.w3.org/2000/svg">  
    <symbol id="home" viewBox="0 0 32 32">  
      <path d="M32 19l-6-..."></path>  
    <symbol id="camera" viewBox="0 0 32 32">  
        d="M9.5 19c0..."></path>  
    <symbol id="headphones" viewBox="0 0 32 32">  
      <path d="M9 18h-2v..."></path>  
      <path d="M23 18c-0.55..."></path>  

This is the actual SVG data to draw the icons. It uses symbol tags to make the shapes reusable. For instance, &lt;use xlink:href="#camera"&gt;&lt;/use&gt; will take contents of the symbol with id="camera" and replicate it.

An easy way to create this file is with the IcoMoon app. You select the icons from various icon packs and download a custom pack that includes a symbol-defs.svg with the selected icons in the format we need.

You can also create and export your own icons using a vector drawing software like, Sketch, Illustrator or Inkscape.

Setup SVG Sprite Loader

In order for the xlink:href find the SVG data, the contents of the icons.svg file must be injected inside the body of the page. To make this happen, we will use the Webpack loader svg-sprite-loader.

Note: xlink:href can also work with external SVG files, like this: xlink:href="icons.svg#camera", but as this post by Chris Coyer points out, it has some drawbacks and compatibility issues with older browsers, so we’ll go the safest route.

To use the svg-sprite-loader, just install it (npm i -D svg-sprite-loader) and add to your Webpack config, inside module.rules:

  test: /\.svg$/,  
  loader: 'svg-sprite-loader'  

With this default config, the loader will intercept imported SVG files, like the import './icons.svg’ in our component, and inject the contents on top of the page body. It will add the name of the file as a prefix to the symbol ids, so &lt;symbol id="camera"&gt; in our original icons.svg file, becomes &lt;symbol id="icons_camera"&gt;. That’s why our component has xlinkHref={`#icons_${props.name}`}.

The complete code can be found here: https://github.com/doug2k1/react-svg-icon

I hope this can be useful. Let me know if you have any suggestions.



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