page size and unsaved changes contr. refactor

app/javascript/controllers/unsaved_changes_controller.js

@@ -1,36 +1,32 @@
 import { Controller } from "@hotwired/stimulus"
 
+const LEAVE_ALERT = "Es gibt ungespeicherte Änderungen! Wirklich verlassen?"
+
 // Connects to data-controller="unsaved-changes"
 export default class extends Controller {
-  originalFormData = null
+  initialState = null
 
   connect() {
-    this.originalFormData = this.formState()
+    this.initialState = this.formState()
 
     window.addEventListener("beforeunload", (event) => this.leavingPage(event))
-    document.addEventListener('turbo:before-visit', (e) => this.leavingPage(e));
-    this.element.addEventListener("submit", _ => this.originalFormData = this.formState())
+    document.addEventListener('turbo:before-visit', (e) => this.leavingPage(e))
+    this.element.addEventListener("submit", (_) => this.initialState = this.formState())
   } 
 
   formState() {
     return JSON.stringify(Array.from(new FormData(this.element).entries())
-                               .filter(x => x[1] != ""))
+                               .filter(x => x[1] != "")
+                               .sort(x => x[0]))
   }
   
   leavingPage(event) {
-    if(this.originalFormData == this.formState()) {
+    if(this.initialState == this.formState()) {
       return
     }
 
-    if (event.type == "turbo:before-visit") {
-      if (!window.confirm("Es gibt ungespeicherte Änderungen! Wirklich verlassen?")) { 
-        event.preventDefault()
-      }
-    } else {
-      if (!window.confirm("Es gibt ungespeicherte Änderungen! Wirklich verlassen?")) { 
-        event.preventDefault()
-      }
-      return event.returnValue;
+    if (!window.confirm(LEAVE_ALERT)) { 
+      event.preventDefault()
     }
   }
 }