implement fragments for sharing

quiplibre.html

@@ -24,7 +24,11 @@ <h1 id="roomname">Quiplibre</h1>
 <script>
 form.addEventListener("submit", function(event){event.preventDefault();}, false);
 
-function toQuiplibreRoomId(s){return "quiplibre_"+(s.toLowerCase().replace(/[^a-z]/g, ""));}
+//join if we have a fragment, for sharing purposes.
+if(window.location.hash){join(window.location.hash.substring(1))};
+
+function toQuiplibreSlug(s){return s.toLowerCase().replace(/[^a-z0-9]/g, "");}
+function toQuiplibreRoomId(s){return "quiplibre_"+toQuiplibreSlug(s);}
 function errorAlert(error){
   alert("There has been a networking error; if you find yourself unable to play, please refresh the page.\n"+error);
   console.log(error);
@@ -77,7 +81,7 @@ <h1 id="roomname">Quiplibre</h1>
 //big screen stuff
 function becomeBigScreen(name){
 roomname.innerHTML += ": "+name
-playDiv.innerHTML = "Hi, welcome to Quiplibre! Visit https://wyattscarpenter.github.io/quiplibre/ to join! Room code: "+name+"<br>"+
+playDiv.innerHTML = "Hi, welcome to Quiplibre! Visit https://wyattscarpenter.github.io/quiplibre#"+toQuiplibreSlug(name)+" to join! Room code: "+name+"<br>"+
   "No players established.<br>"+
   "(You need at least two people to connect in order to play Quiplibre.)";
 buttonDiv.style = ""; //show, by removing display: none;