From 399e262f32c5d554697a4c148fd08e54d7650064 Mon Sep 17 00:00:00 2001
From: Roy Meissner <meissner@informatik.uni-leipzig.de>
Date: Fri, 28 Sep 2018 11:21:30 +0200
Subject: [PATCH 1/2] Fixed SWIK-2088

---
 components/Deck/Presentation/Presentation.js | 38 +++++++++++++++++++-
 1 file changed, 37 insertions(+), 1 deletion(-)

diff --git a/components/Deck/Presentation/Presentation.js b/components/Deck/Presentation/Presentation.js
index aeb4fa6cb..ea7803103 100644
--- a/components/Deck/Presentation/Presentation.js
+++ b/components/Deck/Presentation/Presentation.js
@@ -21,8 +21,41 @@ class Presentation extends React.Component{
         this.id = props.currentRoute.query.id;
     }
 
+    //setting/reading a cookie is needed so SWIK-2088 is fixable
+    setCookie(name,value,seconds) {
+        let expires = '';
+        if (seconds) {
+            let date = new Date();
+            date.setTime(date.getTime() + (seconds*1000));
+            expires = '; expires=' + date.toUTCString();
+        }
+        document.cookie = name + '=' + (value || '')  + expires + '; path=/';
+    }
+    getCookie(name) {
+        let nameEQ = name + '=';
+        let ca = document.cookie.split(';');
+        for(let i=0;i < ca.length;i++) {
+            let c = ca[i];
+            while (c.charAt(0)===' ') c = c.substring(1,c.length);
+            if (c.indexOf(nameEQ) === 0) return c.substring(nameEQ.length,c.length);
+        }
+        return undefined;
+    }
+    eraseCookie(name) {
+        document.cookie = name+'=; Max-Age=-99999999;';
+    }
+
     componentDidMount(){
         if(process.env.BROWSER){
+
+            window.addEventListener('beforeunload', (event) => {
+                this.setCookie('lastHash',window.location.hash, 15);
+            });
+
+            let lastRevealHash = this.getCookie('lastHash');
+            console.log(lastRevealHash);
+            this.eraseCookie('lastHash');
+
             //$('[style*="absolute"]').children().attr('tabindex', 0);
 
             //remove existing tabindices
@@ -62,7 +95,10 @@ class Presentation extends React.Component{
                 pptxheight = '100%';
             }
 
-            window.location.hash = '#slide-' + this.startingSlide;
+            if(lastRevealHash === undefined)
+                window.location.hash = '#slide-' + this.startingSlide;
+            else
+                window.location.hash = lastRevealHash;
 
             let multiplexFileToLoad = (this.secret) ? '/custom_modules/reveal.js/plugin/multiplex/master.js' : '/custom_modules/reveal.js/plugin/multiplex/client.js' ;
             multiplexFileToLoad = (this.id) ? multiplexFileToLoad : '' ;

From a199c09ee80a242d280750ce00d1226b298f2d81 Mon Sep 17 00:00:00 2001
From: Roy Meissner <meissner@informatik.uni-leipzig.de>
Date: Fri, 28 Sep 2018 15:38:50 +0200
Subject: [PATCH 2/2] Moved from cookies to localstorage

---
 components/Deck/Presentation/Presentation.js | 44 +++++++-------------
 1 file changed, 16 insertions(+), 28 deletions(-)

diff --git a/components/Deck/Presentation/Presentation.js b/components/Deck/Presentation/Presentation.js
index ea7803103..de8feb77a 100644
--- a/components/Deck/Presentation/Presentation.js
+++ b/components/Deck/Presentation/Presentation.js
@@ -21,40 +21,28 @@ class Presentation extends React.Component{
         this.id = props.currentRoute.query.id;
     }
 
-    //setting/reading a cookie is needed so SWIK-2088 is fixable
-    setCookie(name,value,seconds) {
-        let expires = '';
-        if (seconds) {
-            let date = new Date();
-            date.setTime(date.getTime() + (seconds*1000));
-            expires = '; expires=' + date.toUTCString();
-        }
-        document.cookie = name + '=' + (value || '')  + expires + '; path=/';
-    }
-    getCookie(name) {
-        let nameEQ = name + '=';
-        let ca = document.cookie.split(';');
-        for(let i=0;i < ca.length;i++) {
-            let c = ca[i];
-            while (c.charAt(0)===' ') c = c.substring(1,c.length);
-            if (c.indexOf(nameEQ) === 0) return c.substring(nameEQ.length,c.length);
-        }
-        return undefined;
-    }
-    eraseCookie(name) {
-        document.cookie = name+'=; Max-Age=-99999999;';
-    }
-
     componentDidMount(){
         if(process.env.BROWSER){
 
             window.addEventListener('beforeunload', (event) => {
-                this.setCookie('lastHash',window.location.hash, 15);
+                if(window.localStorage)
+                    window.localStorage.setItem('lastHash', JSON.stringify({'hash': window.location.hash, 'time': new Date().getTime(), 'deckID': this.props.PresentationStore.selector.id}) );//safe current slide for page refresh
             });
 
-            let lastRevealHash = this.getCookie('lastHash');
-            console.log(lastRevealHash);
-            this.eraseCookie('lastHash');
+            let lastRevealHash = undefined;
+            if(window.localStorage) {
+                lastRevealHash = window.localStorage.getItem('lastHash');
+                lastRevealHash = (lastRevealHash) ? JSON.parse(lastRevealHash) : undefined;
+                if(lastRevealHash) {
+                    if(lastRevealHash.deckID !== this.props.PresentationStore.selector.id){ //check that it is still the same deck, cause 15 secs is rather long
+                        lastRevealHash = undefined;
+                    } else {
+                        let timePassed = (new Date().getTime()) - lastRevealHash.time;
+                        lastRevealHash = (timePassed > 0 && timePassed <= 15*1000) ? lastRevealHash.hash : undefined;//not older than 15 secs ... just for reload of the page
+                    }
+                }
+                window.localStorage.removeItem('lastHash');
+            }
 
             //$('[style*="absolute"]').children().attr('tabindex', 0);