postcss-font-base64/build/index.js

this postcss plugin will export a font face defined by base64 encoded string

'use strict';

var postcss = require('postcss');
var path = require('path');
var fs = require('fs');
var glob = require('glob');

module.exports = postcss.plugin('postcss-font-base64', function (options) {
  // handle options here
  options = options || {};

  // default options
  options.match = options.match || { 'Scrabble': ['fakefont'] };
  options.format = options.format || ['eot', 'woff', 'woff2', 'ttf'];

  // constiables
  var CWD = path.resolve(process.cwd());

  return function (css, result) {
    // Runs through all of the nodes (declarations) in the css
    css.walkAtRules('font-face', function (fontFace) {
      var fileTypeRegex = getRegexStringForFileTypes(options.format);

      // TODO: Return here if font-family doesn't match options.match

      fontFace.replaceValues(new RegExp('url\\("?.+\\.' + fileTypeRegex + '"?\\)'), function (attr) {
        var fontSource = attr.replace(/(url|"|\(|\)|\?#iefix)/g, '');

        // TODO: Return here if font filename doesn't match options.match

        var res64 = base64Encode(fontSource);
        var newUrlStr = 'url(data:'.concat(getMimeType(attr)).concat(';charset=utf-8;base64,').concat(res64).concat(')');

        return res64 ? newUrlStr : attr;
      });
    });

    function getRegexStringForFileTypes(fileTypes) {
      var regex = fileTypes.map(function (fileType) {
        return fileType === 'eot' ? fileType.concat('(\\?#iefix)?') : fileType;
      }).join('|');
      return regex ? '(' + regex + ')' : '';
    }

    // helper functions
    function getMimeType(attribute) {
      var formats = {
        '.woff': 'application/font-woff',
        '.woff2': 'font/woff2',
        '.ttf': 'application/font-sfnt',
        '.eot': 'application/vnd.ms-fontobject',
        '.otf': 'application/font-sfnt'
      };

      var match = '';
      var extension = attribute.match(/\.[a-z]{3,4}/)[0];

      if (extension in formats) {
        match = formats[extension];
      };
      return match;
    };

    function base64Encode(file) {
      if (fs.existsSync(file)) {
        return readAndEncodeFile(file);
      } else {
        // Fallback to glob
        file = glob.sync('**/' + file)[0]; // Could be smarter

        if (fs.existsSync(file)) {
          return readAndEncodeFile(file);
        }

        console.warn(file, 'does not exist.');
        return '';
      }
    }

    function readAndEncodeFile(file) {
      var bitmap = fs.readFileSync(file);
      return new Buffer(bitmap).toString('base64');
    }
  };
});