Edit

[EDIT] FILE: pace.js

defaultOptions = {
    catchupTime: 100,
    initialRate: .03,
    minTime: 250,
    ghostTime: 100,
    maxProgressPerFrame: 20,
    easeFactor: 1.25,
    startOnPageLoad: true,
    restartOnPushState: true,
    restartOnRequestAfter: 500,
    target: 'body',
    elements: {
      checkInterval: 100,
      selectors: ['body']
    },
    eventLag: {
      minSamples: 10,
      sampleCount: 3,
      lagThreshold: 3
    },
    ajax: {
      trackMethods: ['GET'],
      trackWebSockets: true,
      ignoreURLs: []
    }
  };

now = function() {
    var ref;
    return (ref = typeof performance !== "undefined" && performance !== null ? typeof performance.now === "function" ? performance.now() : void 0 : void 0) != null ? ref : +(new Date);
  };

requestAnimationFrame = window.requestAnimationFrame || window.mozRequestAnimationFrame || window.webkitRequestAnimationFrame || window.msRequestAnimationFrame;

cancelAnimationFrame = window.cancelAnimationFrame || window.mozCancelAnimationFrame;

if (requestAnimationFrame == null) {
    requestAnimationFrame = function(fn) {
      return setTimeout(fn, 50);
    };
    cancelAnimationFrame = function(id) {
      return clearTimeout(id);
    };
  }

runAnimation = function(fn) {
    var last, tick;
    last = now();
    tick = function() {
      var diff;
      diff = now() - last;
      if (diff >= 33) {
        last = now();
        return fn(diff, function() {
          return requestAnimationFrame(tick);
        });
      } else {
        return setTimeout(tick, 33 - diff);
      }
    };
    return tick();
  };

result = function() {
    var args, key, obj;
    obj = arguments[0], key = arguments[1], args = 3 <= arguments.length ? slice.call(arguments, 2) : [];
    if (typeof obj[key] === 'function') {
      return obj[key].apply(obj, args);
    } else {
      return obj[key];
    }
  };

extend = function() {
    var k, key, len, out, source, sources, val;
    out = arguments[0], sources = 2 <= arguments.length ? slice.call(arguments, 1) : [];
    for (k = 0, len = sources.length; k < len; k++) {
      source = sources[k];
      if (source) {
        for (key in source) {
          if (!hasProp.call(source, key)) continue;
          val = source[key];
          if ((out[key] != null) && typeof out[key] === 'object' && (val != null) && typeof val === 'object') {
            extend(out[key], val);
          } else {
            out[key] = val;
          }
        }
      }
    }
    return out;
  };

avgAmplitude = function(arr) {
    var count, k, len, sum, v;
    sum = count = 0;
    for (k = 0, len = arr.length; k < len; k++) {
      v = arr[k];
      sum += Math.abs(v);
      count++;
    }
    return sum / count;
  };

getFromDOM = function(key, json) {
    var data, e, el, error;
    if (key == null) {
      key = 'options';
    }
    if (json == null) {
      json = true;
    }
    el = document.querySelector("[data-pace-" + key + "]");
    if (!el) {
      return;
    }
    data = el.getAttribute("data-pace-" + key);
    if (!json) {
      return data;
    }
    try {
      return JSON.parse(data);
    } catch (error) {
      e = error;
      return typeof console !== "undefined" && console !== null ? console.error("Error parsing inline pace options", e) : void 0;
    }
  };

Evented = (function() {
    function Evented() {}

Evented.prototype.on = function(event, handler, ctx, once) {
      var base;
      if (once == null) {
        once = false;
      }
      if (this.bindings == null) {
        this.bindings = {};
      }
      if ((base = this.bindings)[event] == null) {
        base[event] = [];
      }
      return this.bindings[event].push({
        handler: handler,
        ctx: ctx,
        once: once
      });
    };

Evented.prototype.once = function(event, handler, ctx) {
      return this.on(event, handler, ctx, true);
    };

Evented.prototype.off = function(event, handler) {
      var i, ref, results;
      if (((ref = this.bindings) != null ? ref[event] : void 0) == null) {
        return;
      }
      if (handler == null) {
        return delete this.bindings[event];
      } else {
        i = 0;
        results = [];
        while (i < this.bindings[event].length) {
          if (this.bindings[event][i].handler === handler) {
            results.push(this.bindings[event].splice(i, 1));
          } else {
            results.push(i++);
          }
        }
        return results;
      }
    };

Evented.prototype.trigger = function() {
      var args, ctx, event, handler, i, once, ref, ref1, results;
      event = arguments[0], args = 2 <= arguments.length ? slice.call(arguments, 1) : [];
      if ((ref = this.bindings) != null ? ref[event] : void 0) {
        i = 0;
        results = [];
        while (i < this.bindings[event].length) {
          ref1 = this.bindings[event][i], handler = ref1.handler, ctx = ref1.ctx, once = ref1.once;
          handler.apply(ctx != null ? ctx : this, args);
          if (once) {
            results.push(this.bindings[event].splice(i, 1));
          } else {
            results.push(i++);
          }
        }
        return results;
      }
    };

return Evented;

})();

Pace = window.Pace || {};

window.Pace = Pace;

extend(Pace, Evented.prototype);

options = Pace.options = extend({}, defaultOptions, window.paceOptions, getFromDOM());

ref = ['ajax', 'document', 'eventLag', 'elements'];
  for (k = 0, len = ref.length; k < len; k++) {
    source = ref[k];
    if (options[source] === true) {
      options[source] = defaultOptions[source];
    }
  }

NoTargetError = (function(superClass) {
    extend1(NoTargetError, superClass);

function NoTargetError() {
      return NoTargetError.__super__.constructor.apply(this, arguments);
    }

return NoTargetError;

})(Error);

Bar = (function() {
    function Bar() {
      this.progress = 0;
    }

Bar.prototype.getElement = function() {
      var targetElement;
      if (this.el == null) {
        targetElement = document.querySelector(options.target);
        if (!targetElement) {
          throw new NoTargetError;
        }
        this.el = document.createElement('div');
        this.el.classList.add('pace');
        this.el.classList.add('pace-active');
        document.body.classList.remove('pace-done');
        document.body.classList.add('pace-running');
        this.el.innerHTML = '<div class="pace-progress">\n  <div class="pace-progress-inner"></div>\n</div>\n<div class="pace-activity"></div>';
        if (targetElement.firstChild != null) {
          targetElement.insertBefore(this.el, targetElement.firstChild);
        } else {
          targetElement.appendChild(this.el);
        }
      }
      return this.el;
    };

Bar.prototype.finish = function() {
      var el;
      el = this.getElement();
      el.classList.remove('pace-active');
      el.classList.add('pace-inactive');
      document.body.classList.remove('pace-running');
      return document.body.classList.add('pace-done');
    };

Bar.prototype.update = function(prog) {
      this.progress = prog;
      return this.render();
    };

Bar.prototype.destroy = function() {
      var error;
      try {
        this.getElement().parentNode.removeChild(this.getElement());
      } catch (error) {
        NoTargetError = error;
      }
      return this.el = void 0;
    };

Bar.prototype.render = function() {
      var el, key, l, len1, progressStr, ref1, transform;
      if (document.querySelector(options.target) == null) {
        return false;
      }
      el = this.getElement();
      transform = "translate3d(" + this.progress + "%, 0, 0)";
      ref1 = ['webkitTransform', 'msTransform', 'transform'];
      for (l = 0, len1 = ref1.length; l < len1; l++) {
        key = ref1[l];
        el.children[0].style[key] = transform;
      }
      if (!this.lastRenderedProgress || this.lastRenderedProgress | 0 !== this.progress | 0) {
        el.children[0].setAttribute('data-progress-text', (this.progress | 0) + "%");
        if (this.progress >= 100) {
          progressStr = '99';
        } else {
          progressStr = this.progress < 10 ? "0" : "";
          progressStr += this.progress | 0;
        }
        el.children[0].setAttribute('data-progress', "" + progressStr);
      }
      return this.lastRenderedProgress = this.progress;
    };

Bar.prototype.done = function() {
      return this.progress >= 100;
    };

return Bar;

})();

Events = (function() {
    function Events() {
      this.bindings = {};
    }

Events.prototype.trigger = function(name, val) {
      var binding, l, len1, ref1, results;
      if (this.bindings[name] != null) {
        ref1 = this.bindings[name];
        results = [];
        for (l = 0, len1 = ref1.length; l < len1; l++) {
          binding = ref1[l];
          results.push(binding.call(this, val));
        }
        return results;
      }
    };

Events.prototype.on = function(name, fn) {
      var base;
      if ((base = this.bindings)[name] == null) {
        base[name] = [];
      }
      return this.bindings[name].push(fn);
    };

return Events;

})();

_XMLHttpRequest = window.XMLHttpRequest;

_XDomainRequest = window.XDomainRequest;

_WebSocket = window.WebSocket;

extendNative = function(to, from) {
    var e, error, key, results;
    results = [];
    for (key in from.prototype) {
      try {
        if ((to[key] == null) && typeof from[key] !== 'function') {
          if (typeof Object.defineProperty === 'function') {
            results.push(Object.defineProperty(to, key, {
              get: function() {
                return from.prototype[key];
              },
              configurable: true,
              enumerable: true
            }));
          } else {
            results.push(to[key] = from.prototype[key]);
          }
        } else {
          results.push(void 0);
        }
      } catch (error) {
        e = error;
      }
    }
    return results;
  };

ignoreStack = [];

Pace.ignore = function() {
    var args, fn, ret;
    fn = arguments[0], args = 2 <= arguments.length ? slice.call(arguments, 1) : [];
    ignoreStack.unshift('ignore');
    ret = fn.apply(null, args);
    ignoreStack.shift();
    return ret;
  };

Pace.track = function() {
    var args, fn, ret;
    fn = arguments[0], args = 2 <= arguments.length ? slice.call(arguments, 1) : [];
    ignoreStack.unshift('track');
    ret = fn.apply(null, args);
    ignoreStack.shift();
    return ret;
  };

shouldTrack = function(method) {
    var ref1;
    if (method == null) {
      method = 'GET';
    }
    if (ignoreStack[0] === 'track') {
      return 'force';
    }
    if (!ignoreStack.length && options.ajax) {
      if (method === 'socket' && options.ajax.trackWebSockets) {
        return true;
      } else if (ref1 = method.toUpperCase(), indexOf.call(options.ajax.trackMethods, ref1) >= 0) {
        return true;
      }
    }
    return false;
  };

RequestIntercept = (function(superClass) {
    extend1(RequestIntercept, superClass);

return RequestIntercept;

})(Events);

_intercept = null;

getIntercept = function() {
    if (_intercept == null) {
      _intercept = new RequestIntercept;
    }
    return _intercept;
  };

shouldIgnoreURL = function(url) {
    var l, len1, pattern, ref1;
    ref1 = options.ajax.ignoreURLs;
    for (l = 0, len1 = ref1.length; l < len1; l++) {
      pattern = ref1[l];
      if (typeof pattern === 'string') {
        if (url.indexOf(pattern) !== -1) {
          return true;
        }
      } else {
        if (pattern.test(url)) {
          return true;
        }
      }
    }
    return false;
  };

getIntercept().on('request', function(arg) {
    var after, args, request, type, url;
    type = arg.type, request = arg.request, url = arg.url;
    if (shouldIgnoreURL(url)) {
      return;
    }
    if (!Pace.running && (options.restartOnRequestAfter !== false || shouldTrack(type) === 'force')) {
      args = arguments;
      after = options.restartOnRequestAfter || 0;
      if (typeof after === 'boolean') {
        after = 0;
      }
      return setTimeout(function() {
        var l, len1, ref1, ref2, results, stillActive;
        if (type === 'socket') {
          stillActive = request.readyState < 2;
        } else {
          stillActive = (0 < (ref1 = request.readyState) && ref1 < 4);
        }
        if (stillActive) {
          Pace.restart();
          ref2 = Pace.sources;
          results = [];
          for (l = 0, len1 = ref2.length; l < len1; l++) {
            source = ref2[l];
            if (source instanceof AjaxMonitor) {
              source.watch.apply(source, args);
              break;
            } else {
              results.push(void 0);
            }
          }
          return results;
        }
      }, after);
    }
  });

AjaxMonitor = (function() {
    function AjaxMonitor() {
      this.elements = [];
      getIntercept().on('request', (function(_this) {
        return function() {
          return _this.watch.apply(_this, arguments);
        };
      })(this));
    }

AjaxMonitor.prototype.watch = function(arg) {
      var request, tracker, type, url;
      type = arg.type, request = arg.request, url = arg.url;
      if (shouldIgnoreURL(url)) {
        return;
      }
      if (type === 'socket') {
        tracker = new SocketRequestTracker(request);
      } else {
        tracker = new XHRRequestTracker(request);
      }
      return this.elements.push(tracker);
    };

return AjaxMonitor;

})();

XHRRequestTracker = (function() {
    function XHRRequestTracker(request) {
      var _onreadystatechange, event, l, len1, ref1, size;
      this.progress = 0;
      if (window.ProgressEvent != null) {
        size = null;
        request.addEventListener('progress', (function(_this) {
          return function(evt) {
            if (evt.lengthComputable) {
              return _this.progress = 100 * evt.loaded / evt.total;
            } else {
              return _this.progress = _this.progress + (100 - _this.progress) / 2;
            }
          };
        })(this), false);
        ref1 = ['load', 'abort', 'timeout', 'error'];
        for (l = 0, len1 = ref1.length; l < len1; l++) {
          event = ref1[l];
          request.addEventListener(event, (function(_this) {
            return function() {
              return _this.progress = 100;
            };
          })(this), false);
        }
      } else {
        _onreadystatechange = request.onreadystatechange;
        request.onreadystatechange = (function(_this) {
          return function() {
            var ref2;
            if ((ref2 = request.readyState) === 0 || ref2 === 4) {
              _this.progress = 100;
            } else if (request.readyState === 3) {
              _this.progress = 50;
            }
            return typeof _onreadystatechange === "function" ? _onreadystatechange.apply(null, arguments) : void 0;
          };
        })(this);
      }
    }

return XHRRequestTracker;

})();

SocketRequestTracker = (function() {
    function SocketRequestTracker(request) {
      var event, l, len1, ref1;
      this.progress = 0;
      ref1 = ['error', 'open'];
      for (l = 0, len1 = ref1.length; l < len1; l++) {
        event = ref1[l];
        request.addEventListener(event, (function(_this) {
          return function() {
            return _this.progress = 100;
          };
        })(this), false);
      }
    }

return SocketRequestTracker;

})();

ElementMonitor = (function() {
    function ElementMonitor(options) {
      var l, len1, ref1, selector;
      if (options == null) {
        options = {};
      }
      this.elements = [];
      if (options.selectors == null) {
        options.selectors = [];
      }
      ref1 = options.selectors;
      for (l = 0, len1 = ref1.length; l < len1; l++) {
        selector = ref1[l];
        this.elements.push(new ElementTracker(selector));
      }
    }

return ElementMonitor;

})();

ElementTracker = (function() {
    function ElementTracker(selector1) {
      this.selector = selector1;
      this.progress = 0;
      this.check();
    }

ElementTracker.prototype.check = function() {
      if (document.querySelector(this.selector)) {
        return this.done();
      } else {
        return setTimeout(((function(_this) {
          return function() {
            return _this.check();
          };
        })(this)), options.elements.checkInterval);
      }
    };

ElementTracker.prototype.done = function() {
      return this.progress = 100;
    };

return ElementTracker;

})();

DocumentMonitor = (function() {
    DocumentMonitor.prototype.states = {
      loading: 0,
      interactive: 50,
      complete: 100
    };

return DocumentMonitor;

})();

EventLagMonitor = (function() {
    function EventLagMonitor() {
      var avg, interval, last, points, samples;
      this.progress = 0;
      avg = 0;
      samples = [];
      points = 0;
      last = now();
      interval = setInterval((function(_this) {
        return function() {
          var diff;
          diff = now() - last - 50;
          last = now();
          samples.push(diff);
          if (samples.length > options.eventLag.sampleCount) {
            samples.shift();
          }
          avg = avgAmplitude(samples);
          if (++points >= options.eventLag.minSamples && avg < options.eventLag.lagThreshold) {
            _this.progress = 100;
            return clearInterval(interval);
          } else {
            return _this.progress = 100 * (3 / (avg + 3));
          }
        };
      })(this), 50);
    }

return EventLagMonitor;

})();

Scaler = (function() {
    function Scaler(source1) {
      this.source = source1;
      this.last = this.sinceLastUpdate = 0;
      this.rate = options.initialRate;
      this.catchup = 0;
      this.progress = this.lastProgress = 0;
      if (this.source != null) {
        this.progress = result(this.source, 'progress');
      }
    }

Scaler.prototype.tick = function(frameTime, val) {
      var scaling;
      if (val == null) {
        val = result(this.source, 'progress');
      }
      if (val >= 100) {
        this.done = true;
      }
      if (val === this.last) {
        this.sinceLastUpdate += frameTime;
      } else {
        if (this.sinceLastUpdate) {
          this.rate = (val - this.last) / this.sinceLastUpdate;
        }
        this.catchup = (val - this.progress) / options.catchupTime;
        this.sinceLastUpdate = 0;
        this.last = val;
      }
      if (val > this.progress) {
        this.progress += this.catchup * frameTime;
      }
      scaling = 1 - Math.pow(this.progress / 100, options.easeFactor);
      this.progress += scaling * this.rate * frameTime;
      this.progress = Math.min(this.lastProgress + options.maxProgressPerFrame, this.progress);
      this.progress = Math.max(0, this.progress);
      this.progress = Math.min(100, this.progress);
      this.lastProgress = this.progress;
      return this.progress;
    };

return Scaler;

})();

sources = null;

scalers = null;

bar = null;

uniScaler = null;

animation = null;

cancelAnimation = null;

Pace.running = false;

handlePushState = function() {
    if (options.restartOnPushState) {
      return Pace.restart();
    }
  };

if (window.history.pushState != null) {
    _pushState = window.history.pushState;
    window.history.pushState = function() {
      handlePushState();
      return _pushState.apply(window.history, arguments);
    };
  }

if (window.history.replaceState != null) {
    _replaceState = window.history.replaceState;
    window.history.replaceState = function() {
      handlePushState();
      return _replaceState.apply(window.history, arguments);
    };
  }

SOURCE_KEYS = {
    ajax: AjaxMonitor,
    elements: ElementMonitor,
    document: DocumentMonitor,
    eventLag: EventLagMonitor
  };

(init = function() {
    var l, len1, len2, m, ref1, ref2, ref3, type;
    Pace.sources = sources = [];
    ref1 = ['ajax', 'elements', 'document', 'eventLag'];
    for (l = 0, len1 = ref1.length; l < len1; l++) {
      type = ref1[l];
      if (options[type] !== false) {
        sources.push(new SOURCE_KEYS[type](options[type]));
      }
    }
    ref3 = (ref2 = options.extraSources) != null ? ref2 : [];
    for (m = 0, len2 = ref3.length; m < len2; m++) {
      source = ref3[m];
      sources.push(new source(options));
    }
    Pace.bar = bar = new Bar;
    scalers = [];
    return uniScaler = new Scaler;
  })();

Pace.stop = function() {
    Pace.trigger('stop');
    Pace.running = false;
    bar.destroy();
    cancelAnimation = true;
    if (animation != null) {
      if (typeof cancelAnimationFrame === "function") {
        cancelAnimationFrame(animation);
      }
      animation = null;
    }
    return init();
  };

Pace.restart = function() {
    Pace.trigger('restart');
    Pace.stop();
    return Pace.start();
  };

Pace.go = function() {
    var start;
    Pace.running = true;
    bar.render();
    start = now();
    cancelAnimation = false;
    return animation = runAnimation(function(frameTime, enqueueNextFrame) {
      var avg, count, done, element, elements, i, j, l, len1, len2, m, ref1, remaining, scaler, scalerList, sum;
      remaining = 100 - bar.progress;
      count = sum = 0;
      done = true;
      for (i = l = 0, len1 = sources.length; l < len1; i = ++l) {
        source = sources[i];
        scalerList = scalers[i] != null ? scalers[i] : scalers[i] = [];
        elements = (ref1 = source.elements) != null ? ref1 : [source];
        for (j = m = 0, len2 = elements.length; m < len2; j = ++m) {
          element = elements[j];
          scaler = scalerList[j] != null ? scalerList[j] : scalerList[j] = new Scaler(element);
          done &= scaler.done;
          if (scaler.done) {
            continue;
          }
          count++;
          sum += scaler.tick(frameTime);
        }
      }
      avg = sum / count;
      bar.update(uniScaler.tick(frameTime, avg));
      if (bar.done() || done || cancelAnimation) {
        bar.update(100);
        Pace.trigger('done');
        return setTimeout(function() {
          bar.finish();
          Pace.running = false;
          return Pace.trigger('hide');
        }, Math.max(options.ghostTime, Math.max(options.minTime - (now() - start), 0)));
      } else {
        return enqueueNextFrame();
      }
    });
  };

Pace.start = function(_options) {
    var error;
    extend(options, _options);
    Pace.running = true;
    try {
      bar.render();
    } catch (error) {
      NoTargetError = error;
    }
    if (!document.querySelector('.pace')) {
      return setTimeout(Pace.start, 50);
    } else {
      Pace.trigger('start');
      return Pace.go();
    }
  };

if (typeof exports === 'object') {
    module.exports = Pace;
  }

if (options.startOnPageLoad) {
    Pace.start();
  }

}).call(this);

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