slurpah.js

slurpah.js

(function(){
  var externalStylesheets = [];
  var fonts = {};

  function findExternalStylesheets(obj, callback) {
    sheet = document.styleSheets,
    i = sheet.length,
    rule = null;
    while( 0 <= --i ) {
      if (sheet[i].cssRules === null) {
        obj.push(sheet[i].href);
      }
    }
    callback();
  }

  function fetchStylesheets() {
    externalStylesheets.forEach(loadCSSCors);
  
    var ctr = 1;
  
    function run_me_when_finished() {
      console.log('I should load after the stylesheets have been added');
    }
  
    function loadCSSCors(stylesheet_uri) {
      var _xhr = window.XMLHttpRequest;
      var has_cred = false;
      try {has_cred = _xhr && ('withCredentials' in (new _xhr()));} catch(e) {}
      if (!has_cred) {
        console.error('CORS not supported');
        return;
      }
      var xhr = new _xhr();
      xhr.open('GET', stylesheet_uri);
      xhr.onload = function() {
        console.log('o shit waddup');
        xhr.onload = xhr.onerror = null;
        if (xhr.status < 200 || xhr.status >=300) {
          console.error('style failed to load: ' + stylesheet_uri)
        } else {
          var style_tag = document.createElement('style');
          style_tag.appendChild(document.createTextNode(xhr.responseText));
          document.head.appendChild(style_tag);
  
          if (ctr === externalStylesheets.length) {
            return run_me_when_finished();
          }
  
          ctr++;
        };
        xhr.onerror = function() {
          xhr.onload = xhr.onerror = null;
          console.error('XHR CORS CSS fail:' + styleURI);
        };
      }
      xhr.send();
    }
  }

  function getFonts(obj) {
    var o = obj || {},
      sheet = document.styleSheets,
      rule = null,
      i = sheet.length, j;
    while( 0 <= --i ) {
      rule = sheet[i].rules || sheet[i].cssRules || [];
      j = rule.length;
      while( 0 <= --j ) {
        if( rule[j].constructor.name === 'CSSFontFaceRule' ) {
          o[ rule[j].style.fontFamily ] = rule[j].style.src;
        };
      }
    }
    return o;
  }

  findExternalStylesheets(externalStylesheets, fetchStylesheets);
})();