From 0ba41b4c8da30405f346753a7f62ba8050ee5b89 Mon Sep 17 00:00:00 2001
From: Mark Przepiora <mark.przepiora@gmail.com>
Date: Sat, 31 Aug 2013 10:12:35 -0600
Subject: [PATCH 1/2] Store the current page number in the URL, which is
 updated upon each page switch, and the proper page is recalled upon a browser
 refresh

---
 resources/navigation.js | 65 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 65 insertions(+)

diff --git a/resources/navigation.js b/resources/navigation.js
index 083e182..b957e25 100644
--- a/resources/navigation.js
+++ b/resources/navigation.js
@@ -10,6 +10,8 @@ function goBack() {
 
   wrapper.removeChild(lastSlide);
   wrapper.insertBefore(lastSlide, wrapper.firstChild);
+
+  updateURL();
 }
 
 /**
@@ -24,10 +26,73 @@ function goForward() {
 
   wrapper.removeChild(firstSlide);
   wrapper.appendChild(firstSlide);
+
+  updateURL();
+}
+
+/**
+ * Updates the current URL to include a hashtag of the current page number.
+ */
+function updateURL() {
+  window.history.replaceState( {} , null, '#' + currentPage() );
+}
+
+/**
+ * Returns the current page number of the presentation.
+ */
+function currentPage() {
+  return document.querySelector('#wrapper .slide').dataset.page;
+}
+
+/**
+ * Returns a NodeList of each .slide element.
+ */
+function allSlides() {
+  return document.querySelectorAll('#wrapper .slide');
+}
+
+/**
+ * Give each slide a "page" data attribute.
+ */
+function setPageNumbers() {
+  var wrapper = document.querySelector('#wrapper');
+  var pages   = wrapper.querySelectorAll('section');
+
+  for (var i = 0; i < pages.length; ++i) {
+    var page = pages[i];
+    page.dataset.page = i;
+    console.log(page, i);
+  }
+}
+
+/**
+ * Go to the specified page of content.
+ */
+function goToPage(page) {
+  // Try to find the target slide.
+  var targetSlide = document.querySelector('#wrapper .slide[data-page="' + page + '"]');
+
+  // If it actually exists, go forward until we find it.
+  if (targetSlide) {
+    var numSlides = allSlides().length;
+
+    for (var i = 0; currentPage() != page && i < numSlides; i++) {
+      goForward();
+    }
+  }
 }
 
 window.onload = function () {
 
+  // Give each slide a "page" data attribute.
+  setPageNumbers();
+
+  // If the location hash specifies a page number, go to it.
+  var page = window.location.hash.slice(1);
+  if (page) {
+    goToPage(page);
+  }
+
   document.onkeydown = function (e) {
     var kc = e.keyCode;
 

From 2e7126cb96cde10e5b89dd6a73ceca316cc00831 Mon Sep 17 00:00:00 2001
From: Mark Przepiora <mark.przepiora@gmail.com>
Date: Sat, 31 Aug 2013 10:22:09 -0600
Subject: [PATCH 2/2] Remove console.log from code

---
 resources/navigation.js | 1 -
 1 file changed, 1 deletion(-)

diff --git a/resources/navigation.js b/resources/navigation.js
index b957e25..7c68663 100644
--- a/resources/navigation.js
+++ b/resources/navigation.js
@@ -61,7 +61,6 @@ function setPageNumbers() {
   for (var i = 0; i < pages.length; ++i) {
     var page = pages[i];
     page.dataset.page = i;
-    console.log(page, i);
   }
 }