Fix back button; add title

Logic/Actors/HistoryHandling.ts

@@ -0,0 +1,19 @@
+import {UIEventSource} from "../UIEventSource";
+import {UIElement} from "../../UI/UIElement";
+
+export default class HistoryHandling {
+
+    constructor(hash: UIEventSource<string>, fullscreenMessage: UIEventSource<{ content: UIElement, hashText: string }>) {
+        hash.addCallback(h => {
+            if (h === undefined || h === "") {
+                fullscreenMessage.setData(undefined);
+            }
+        })
+        
+        fullscreenMessage.addCallback(fs => {
+            hash.setData(fs?.hashText);
+        })
+        
+    }
+
+}

Logic/Actors/StrayClickHandler.ts

@@ -17,7 +17,7 @@ export default class StrayClickHandler {
         selectedElement: UIEventSource<string>,
         filteredLayers: UIEventSource<{ readonly isDisplayed: UIEventSource<boolean> }[]>,
         leafletMap: UIEventSource<L.Map>,
-        fullscreenMessage: UIEventSource<UIElement>,
+        fullscreenMessage: UIEventSource<{content: UIElement, hashText: string}>,
         uiToShow: (() => UIElement)) {
         this._uiToShow = uiToShow;
         const self = this;
@@ -51,7 +51,7 @@ export default class StrayClickHandler {
             self._lastMarker.bindPopup(popup);
 
             self._lastMarker.on("click", () => {
-                fullscreenMessage.setData(self._uiToShow());
+                fullscreenMessage.setData({content: self._uiToShow(), hashText: "new"});
                 uiElement.Update();
             });
         });

Logic/Actors/TitleHandler.ts

@@ -0,0 +1,33 @@
+import {UIEventSource} from "../UIEventSource";
+import LayoutConfig from "../../Customizations/JSON/LayoutConfig";
+import Translations from "../../UI/i18n/Translations";
+import Locale from "../../UI/i18n/Locale";
+import {UIElement} from "../../UI/UIElement";
+
+export default class TitleHandler{
+    constructor(layoutToUse: UIEventSource<LayoutConfig>, fullScreenMessage: UIEventSource<{ content: UIElement, hashText: string, titleText?: UIElement }>) {
+
+
+        layoutToUse.map((layoutToUse) => {
+                return Translations.WT(layoutToUse?.title)?.txt ?? "MapComplete"
+            }, [Locale.language]
+        ).addCallbackAndRun((title) => {
+            document.title = title
+        });
+
+        fullScreenMessage.addCallbackAndRun(selected => {
+            const title = Translations.WT(layoutToUse.data?.title)?.txt ?? "MapComplete"
+            if(selected?.titleText?.data === undefined){
+                document.title = title
+            }else{
+                selected.titleText.Update();
+                var d = document.createElement('div');
+                d.innerHTML = selected.titleText.InnerRender();
+                const poi = (d.textContent || d.innerText)
+                document.title = title + " | " + poi;
+            }
+        })
+
+
+    }
+}

Logic/Web/Hash.ts

@@ -1,29 +1,52 @@
 import {UIEventSource} from "../UIEventSource";
-import Constants from "../../Models/Constants";
 import {Utils} from "../../Utils";
 
 export default class Hash {
-    
-    public static hash : UIEventSource<string> = Hash.Get();
-    
-    private static Get() : UIEventSource<string>{
-        if(Utils.runningFromConsole){
+
+    public static hash: UIEventSource<string> = Hash.Get();
+
+    /**
+     * Gets the current string, including the pound sign
+     * @constructor
+     */
+    public static Current(): string {
+        if (Hash.hash.data === undefined || Hash.hash.data === "") {
+            return ""
+        } else {
+            return "#" + Hash.hash.data;
+        }
+    }
+
+    private static Get(): UIEventSource<string> {
+        if (Utils.runningFromConsole) {
             return new UIEventSource<string>(undefined);
         }
         const hash = new UIEventSource<string>(window.location.hash.substr(1));
         hash.addCallback(h => {
-            if(h === undefined || h === ""){
+            if (h === "undefined") {
+                console.warn("Got a literal 'undefined' as hash, ignoring")
+                h = undefined;
+            }
+
+            if (h === undefined || h === "") {
                 window.location.hash = "";
                 return;
             }
+
             h = h.replace(/\//g, "_");
             window.location.hash = "#" + h;
         });
+
+
         window.onhashchange = () => {
-            hash.setData(window.location.hash.substr(1))
+            let newValue = window.location.hash.substr(1);
+            if (newValue === "") {
+                newValue = undefined;
+            }
+            hash.setData(newValue)
         }
-        
+
         return hash;
     }
-    
+
 }

Logic/Web/QueryParameters.ts

@@ -43,27 +43,23 @@ export class QueryParameters {
     private static Serialize() {
         const parts = []
         for (const key of QueryParameters.order) {
-            if (QueryParameters.knownSources[key] === undefined || QueryParameters.knownSources[key].data === undefined) {
+            if (QueryParameters.knownSources[key]?.data === undefined) {
                 continue;
             }
             
-            if (QueryParameters.knownSources[key].data === undefined) {
-                continue;
-            }
-
             if (QueryParameters.knownSources[key].data === "undefined") {
                 continue;
             }
 
-
-            if (QueryParameters.knownSources[key].data == QueryParameters.defaults[key]) {
+            if (QueryParameters.knownSources[key].data === QueryParameters.defaults[key]) {
                 continue;
             }
 
             parts.push(encodeURIComponent(key) + "=" + encodeURIComponent(QueryParameters.knownSources[key].data))
         }
         // Don't pollute the history every time a parameter changes
-        history.replaceState(null, "", "?" + parts.join("&") + "#" + Hash.hash.data);
+        
+        history.replaceState(null, "", "?" + parts.join("&") + Hash.Current());
 
     }