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node_modules/stylus/lib/functions/url.js 3.3 KB
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  /*!
   * Stylus - plugin - url
   * Copyright (c) Automattic <developer.wordpress.com>
   * MIT Licensed
   */
  
  /**
   * Module dependencies.
   */
  
  var Compiler = require('../visitor/compiler')
    , events = require('../renderer').events
    , nodes = require('../nodes')
    , parse = require('url').parse
    , extname = require('path').extname
    , utils = require('../utils')
    , fs = require('fs');
  
  /**
   * Mime table.
   */
  
  var defaultMimes = {
      '.gif': 'image/gif'
    , '.png': 'image/png'
    , '.jpg': 'image/jpeg'
    , '.jpeg': 'image/jpeg'
    , '.svg': 'image/svg+xml'
    , '.webp': 'image/webp'
    , '.ttf': 'application/x-font-ttf'
    , '.eot': 'application/vnd.ms-fontobject'
    , '.woff': 'application/font-woff'
    , '.woff2': 'application/font-woff2'
  };
  
  /**
   * Supported encoding types
   */
  var encodingTypes = {
    BASE_64: 'base64',
    UTF8: 'charset=utf-8'
  }
  
  /**
   * Return a url() function with the given `options`.
   *
   * Options:
   *
   *    - `limit` bytesize limit defaulting to 30Kb
   *    - `paths` image resolution path(s), merged with general lookup paths
   *
   * Examples:
   *
   *    stylus(str)
   *      .set('filename', __dirname + '/css/test.styl')
   *      .define('url', stylus.url({ paths: [__dirname + '/public'] }))
   *      .render(function(err, css){ ... })
   *
   * @param {Object} options
   * @return {Function}
   * @api public
   */
  
  module.exports = function(options) {
    options = options || {};
  
    var _paths = options.paths || [];
    var sizeLimit = null != options.limit ? options.limit : 30000;
    var mimes = options.mimes || defaultMimes;
  
    /**
     * @param {object} url - The path to the image you want to encode.
     * @param {object} enc - The encoding for the image. Defaults to base64, the 
     * other valid option is `utf8`.
     */
    function fn(url, enc){
      // Compile the url
      var compiler = new Compiler(url)
        , encoding = encodingTypes.BASE_64;
  
      compiler.isURL = true;
      url = url.nodes.map(function(node){
        return compiler.visit(node);
      }).join('');
  
      // Parse literal
      url = parse(url);
      var ext = extname(url.pathname)
        , mime = mimes[ext]
        , hash = url.hash || ''
        , literal = new nodes.Literal('url("' + url.href + '")')
        , paths = _paths.concat(this.paths)
        , buf
        , result;
  
      // Not supported
      if (!mime) return literal;
  
      // Absolute
      if (url.protocol) return literal;
  
      // Lookup
      var found = utils.lookup(url.pathname, paths);
  
      // Failed to lookup
      if (!found) {
        events.emit(
            'file not found'
          , 'File ' + literal + ' could not be found, literal url retained!'
        );
  
        return literal;
      }
  
      // Read data
      buf = fs.readFileSync(found);
  
      // Too large
      if (false !== sizeLimit && buf.length > sizeLimit) return literal;
  
      if (enc && 'utf8' == enc.first.val.toLowerCase()) {
        encoding = encodingTypes.UTF8;
        result = buf.toString('utf8').replace(/\s+/g, ' ')
          .replace(/[{}\|\\\^~\[\]`"<>#%]/g, function(match) {
            return '%' + match[0].charCodeAt(0).toString(16).toUpperCase();
          }).trim();
      } else {
        result = buf.toString(encoding) + hash;
      }
  
      // Encode
      return new nodes.Literal('url("data:' + mime + ';' +  encoding + ',' + result + '")');
    };
  
    fn.raw = true;
    return fn;
  };
  
  // Exporting default mimes so we could easily access them
  module.exports.mimes = defaultMimes;