grunt-embed-fonts

This module provides a grunt multi-task injecting content of font files into stylesheets using data URIs.

When you develop a HTML5 component, your styling may include special fonts. If the page, which hosts your component has not the same origin, the server has to include the CORS headers in the response with the font file (Access-Control-Allow-Origin: * at least) according to the W3C Font fetching requirements. You should always try to configure the web server to do it to get the best performance. If you cannot, you can embed the fonts in the CSS files by this task, but the size of the base64-encoded fonts for the page to load will be circa 35% greater. Additionally, the browser will load all fonts immediately with the stylesheet, otherwise only the needed font faces and formats would be downloaded.

From version 0.4.0 on, MIME types used by default comply with IANA and W3C WOFF font MIME type specifications. If you need MIME types generated by previous versions (either all types as "font/{file ext}" or all types as "application/x-font-{file ext}"), look at options fontMimeType and xFontMimeType below.

Installation

You need node >= 6, npm and grunt >= 0.4 installed and your project build managed by a Gruntfile with the necessary modules listed in package.json. If you haven't used Grunt before, be sure to check out the [Getting Started] guide, as it explains how to create a Gruntfile as well as install and use Grunt plugins. Once you're familiar with that process, you may install this plugin with this command:

$ npm install grunt-embed-fonts --save-dev

Configuration

Add the embedFonts entry with the embed-fonts task configuration to the options of the grunt.initConfig method:

grunt.initConfig({
  embedFonts: {
    all: {
      files: {
        'dist/css/style.css': ['src/css/style.css']
      }
    }
  }
});

The configuration consists of key-value pairs with the output stylesheet path as a key pointing to the input stylesheet file.

An example from the input stylesheet:

@font-face {
  font-family: 'Test';
  src: url(fonts/test.woff) format("woff");
  font-weight: 400;
  font-style: normal;
}

An example from the generated output stylesheet:

@font-face {
  font-family: 'Test';
  src: url("data:application/font-woff;base64,ZmlsZTgK") format("woff");
  font-weight: 400;
  font-style: normal;
}

MIME types are assigned to font files by their file extension according to the following table:

| File ext. | MIME Type | Since | Note | | --------- | ----------------------------- | ------------- | ----------------------------------- | | .eot | application/vnd.ms-fontobject | December 2005 | | | .otf | application/font-sfnt | March 2013 | earlier application/x-font-opentype | | .svg | image/svg+xml | August 2011 | | | .ttf | application/font-sfnt | March 2013 | earlier application/x-font-truetype | | .woff | application/font-woff | January 2013 | | | .woff2 | font/woff2 | March 2016 | proposed by W3C |

See summarizing post at Stack Overflow and IANA with W3C WOFF specifications for more information.

Options

fontMimeType

Type: Boolean Default value: false

Force using "font/..." MIME Type in the embedded font face definition instead of the latest IANA/W3C recommendation.

grunt.initConfig({
  embedFonts: {
    old: {
      options: {
        fontMimeType: true
      },
      files: {
        'dist/css/style.css': ['src/css/style.css']
      }
    }
  }
});

An example from the input stylesheet:

@font-face {
  font-family: 'Test';
  src: url(fonts/test.woff) format("woff");
  font-weight: 400;
  font-style: normal;
}

An example from the generated output stylesheet:

@font-face {
  font-family: 'Test';
  src: url("data:font/woff;base64,ZmlsZT...") format("woff");
  font-weight: 400;
  font-style: normal;
}

xFontMimeType

Type: Boolean Default value: false

Force using "application/x-font-..." MIME Type in the embedded font face definition instead of the latest IANA/W3C recommendation.

grunt.initConfig({
  embedFonts: {
    old: {
      options: {
        xFontMimeType: true
      },
      files: {
        'dist/css/style.css': ['src/css/style.css']
      }
    }
  }
});

An example from the input stylesheet:

@font-face {
  font-family: 'Test';
  src: url(fonts/test.woff) format("woff");
  font-weight: 400;
  font-style: normal;
}

An example from the generated output stylesheet:

@font-face {
  font-family: 'Test';
  src: url("data:application/x-font-woff;base64,ZmlsZT...") format("woff");
  font-weight: 400;
  font-style: normal;
}

mimeTypeOverrides

Type: Object Default value: {}

Override a MIME typ assignments for one or more specific file extensions to use the value specified in the key-value pair of the options object.

This option has the highest priority; fontMimeType, xFontMimeType and the default MIME type assignment will not apply for the specified file extensions. File extesions not specified by mimeTypeOverrides will be processed by usual rules (first by checking fontMimeType, then by checking xFontMimeType and finally by the choosing the preferred MIME type according to the latest specifications and drafts.)

grunt.initConfig({
  embedFonts: {
    old: {
      options: {
        mimeTypeOverrides: {
          otf: 'application/x-font-opentype'
        }
      },
      files: {
        'dist/css/style.css': ['src/css/style.css']
      }
    }
  }
});

An example from the input stylesheet:

@font-face {
  font-family: 'Test';
  src: url('fonts/test.woff') format("woff")
       url(fonts/test.otf) format("opentype");
  font-weight: 400;
  font-style: normal;
}

An example from the generated output stylesheet:

@font-face {
  font-family: 'Test';
  src: url("data:application/font-woff;base64,ZmlsZT...") format("woff"),
       url("data:application/x-font-opentype;base64,ZmlsZT...") format("opentype");
  font-weight: 400;
  font-style: normal;
}

applyTo

Type: array Default value: ['eot','svg','ttf','otf','woff','woff2']

Only embed specific MIME types.

The benefit of @font-face is that it allows the browser to choose which font-type to use. In some cases it is beneficial to embed only the most common MIME types and have the other files as a fall-back.

grunt.initConfig({
  embedFonts: {
    old: {
      options: {
        applyTo: ['woff']
      },
      files: {
        'dist/css/style.css': ['src/css/style.css']
      }
    }
  }
});

An example from the input stylesheet:

@font-face {
  font-family: 'Test';
  src: url("data:application/font-woff;base64,ZmlsZT...") format("woff"),
       url(fonts/test.otf) format("opentype");
  font-weight: 400;
  font-style: normal;
}

An example from the generated output stylesheet:

@font-face {
  font-family: 'Test';
  src: url("data:application/font-woff;base64,ZmlsZT...") format("woff"),
       url(fonts/test.otf) format("opentype");
  font-weight: 400;
  font-style: normal;
}

only

Type: array Default value: []

Only embed fonts with a name that match any of the RegExps provided.

If you only want to embed some of your fonts, provide an array of RegExps that match their filenames.

grunt.initConfig({
  embedFonts: {
    old: {
      options: {
        only: [/(?<!skip-)font\d+/]
      },
      files: {
        'dist/css/style.css': ['src/css/style.css']
      }
    }
  }
});

An example from the input stylesheet:

@font-face {
  font-family: 'Test';
  src: url(fonts/font12.woff) format("woff"),
       url(fonts/skip-font13.otf) format("opentype");
  font-weight: 400;
  font-style: normal;
}

An example from the generated output stylesheet:

@font-face {
  font-family: 'Test';
  src: url("data:application/font-woff;base64,ZmlsZT...") format("woff"),
       url(fonts/skip-font13.otf) format("opentype");
  font-weight: 400;
  font-style: normal;
}

Loading

Load the plugin in Gruntfile.js:

grunt.loadNpmTasks('grunt-embed-fonts');

Build

Call the embedFonts task:

$ grunt embedFonts

or integrate it to your build sequence in Gruntfile.js:

grunt.registerTask('default', ['embedFonts', ...]);

Notes

This task replaces url(...) expressions in @font-face {...} styles only. Commented out styles are processed too. Paths to the font files are expected to be relative to the stylesheet file path. Already embedded fonts or fonts not in the local file system are ignored.

Contributing

In lieu of a formal styleguide, take care to maintain the existing coding style. Add unit tests for any new or changed functionality. Lint and test your code using Grunt.

License

Copyright (c) 2015-2022 Ferdinand Prantl

Licensed under the MIT license.