meteor/docs/client/links.js

var ignoreWaypoints = true;
var ignoreUrlChange = false;

var deHash = function (hashString) {
  return hashString.slice(1);
};

// need an actual function to only debounce inside the if statement
var actuallyUpdateUrl = _.debounce(function (el) {
  ignoreUrlChange = true;
  window.location.replace("#/" + el.id);
}, 1000);

var updateUrlFromWaypoint = function (el) {
  if (! ignoreWaypoints) {
    actuallyUpdateUrl(el);
  }
};

Meteor.startup(function () {
  $('.main-content [id]').each(function (i, el) {
    if (! $("#nav [href='#/" + el.id + "']").get(0)) {
      // only add waypoints to things that have sidebar links
      return;
    }

    $(el).waypoint(function() {
      updateUrlFromWaypoint(this);
    }, { context: $('.main-content') });
  });

  ignoreWaypoints = false;
});

Tracker.autorun(function () {
  // returns a "location" like object with all of the url parts
  var current = Iron.Location.get();

  // If the URL changes from a waypoint, do nothing
  if (ignoreUrlChange) {
    ignoreUrlChange = false;
    return;
  }

  // If the URL changes, close the sidebar
  Session.set("sidebarOpen", false);

  // redirect routes with no trailing slash
  if (current.path === "/basic") {
    window.location.replace("/basic/");
    return;
  } else if (current.path === "/full") {
    window.location.replace("/full/");
    return;
  }

  if (current.path === "/basic/") {
    Session.set("fullApi", false);
  } else if (current.path === "/full/") {
    Session.set("fullApi", true);
  } else {
    if (current.hash) {
      // XXX COMPAT WITH old docs
      window.location.replace("/full/#/" + deHash(current.hash));
    } else {
      window.location.replace("/basic/");
    }
  }

  if (current.hash) {
    console.log("scrolling!");
    Tracker.afterFlush(function () {
      setTimeout(function () {
        var targetLocation;

        if (current.hash === "#/top") {
          targetLocation = 0;
        } else {
          var selector = "#" + deHash(current.hash).slice(1);
          console.log(selector);
          var foundElement = $(selector);
          if (foundElement.get(0)) {
            targetLocation = $(".main-content").scrollTop() + foundElement.offset().top - $(".main-content").offset().top;
          }
        }

        ignoreWaypoints = true;
        $(".main-content").animate({
            scrollTop: targetLocation
        }, 500, function () {
          ignoreWaypoints = false;
        });
      }, 0);
    });
  }
});