Server Side Rendering

With the introduction of SVG's to Font Awesome we can now render icons on the server if you are generating or serving your pages with JavaScript. By rendering server side you save the browser the effort required to download additional files or perform the rendering calculations. For this example we're going to use a static site generator called Metalsmith (opens new window).

This uses the Font Awesome API

Check out the API docs to learn more about the methods in this page.

Setting Things Up

Clone the project and use the static-site example. Also, remember to install dependencies right after that.

  git clone https://github.com/metalsmith/metalsmith.git \
  cd metalsmith/examples/static-site
 

  npm install \
  npm i --save @fortawesome/fontawesome-svg-core \
  npm i --save @fortawesome/free-solid-svg-icons
 

Create a Helper

Create a file in the static-site directory called helpers.js.

  var Handlebars  = require('handlebars');
  var library     = require('@fortawesome/fontawesome-svg-core').library;
  var dom         = require('@fortawesome/fontawesome-svg-core').dom;
  var icon        = require('@fortawesome/fontawesome-svg-core').icon;
  var fas         = require('@fortawesome/free-solid-svg-icons').fas;

// Adds all the icons from the Solid style into our library for easy lookup
library.add(fas)

Handlebars.registerHelper('fontawesome-css', function () {
return new Handlebars.SafeString(
dom.css()
)
})

Handlebars.registerHelper('fontawesome-icon', function (args) {
return new Handlebars.SafeString(
icon({ prefix: 'fas', iconName: args.hash.icon }).html
)
})

 

Add this to the Metalsmith File

Edit index.js and require the new helper file.

  var Metalsmith  = require('metalsmith');
  var markdown    = require('metalsmith-markdown');
  var layouts     = require('metalsmith-layouts');
  var permalinks  = require('metalsmith-permalinks');

  require('./helpers')

  …
 

Edit Layout & Reference Icon

Edit layouts/layout.html and add this to the <head>. After that change the header.

  <style>
    {{fontawesome-css}}
  </style>
 

  <header>
    <p>
      {{fontawesome-icon icon="home"}} <a href="/">Home</a>
    </p>
  </header>
 

Build the Static Content

  node index.js

Open build/index.html to see the rendered icon.

3 icons repeating

CSS

Server side rendering introduces an interesting problem when we consider the CSS that is needed to render an icon effectively.

  <svg class="svg-inline--fa fa-github fa-w-16 fa-lg" aria-hidden data-fa-i2svg data-prefix="fab" data-icon="github" role="img" viewBox="0 0 496 512" >
   <path fill="currentColor" d="">
   </path>
 </svg>
 

The classes svg-inline--fa, fa-w-16, and fa-lg all have a critical role in controlling the size of the icon and the placement in the DOM. If the CSS is missing when this icon displays in the browser it will flash from a very large icon down to a properly sized one a moment later. Here's how to solve it...

As we saw in the example we can inline the CSS directly into the page.

  <style>
    {{fontawesome-css}}
  </style>
 

This Handlebars helper is calling dom.css() which returns a String representing all the styles required for displaying icons at the correct size. You can link to the external CSS, which is specific to using SVG with JavaScript. It can be found in the svg-with-js/css/fa-svg-with-js.css folder.

Use it similar to this:

  <head>
    <link href="https://use.fontawesome.com/releases/vVERSION/css/svg-with-js.css" rel="stylesheet"></link>
  </head>
 