fix(datepicker): close datepickers on focusout or click outside

frontend/src/utils/form/datepicker.js

@@ -180,14 +180,27 @@ export class Datepicker {
     // change the selected date in the tail.datetime instance if the value of the input element is changed
     this._element.addEventListener('change', setDatepickerDate, { once: true });
 
-    // close the instance on focus loss of the corresponding input element
+    // close the instance on focusout of any element if the target is outside of the instance
-    // (only close the instance if source and target IDs differ, since interactions with the opened datepicker also triggers this event in some cases)
+    window.addEventListener('focusout', event => {
-    this._element.addEventListener('focusout', event => {
+      console.log('focusout', event);
-      if (!event.relatedTarget || event.relatedTarget.id !== event.srcElement.id)
+      const targetIsOutside       = !this.datepickerInstance.dt.contains(event.explicitOriginalTarget);
+      const targetIsNotTimepicker = !this.datepickerInstance.dt.contains(event.relatedTarget);
+      console.log(targetIsOutside, targetIsNotTimepicker);
+      if (targetIsOutside && targetIsNotTimepicker)
+        this.datepickerInstance.close();
+    });
+    
+    // close the instance on click on any element outside of the datepicker (except the input element itself)
+    window.addEventListener('click', event => {
+      const targetIsOutside    = !this.datepickerInstance.dt.contains(event.target);
+      const targetIsInDocument = window.document.contains(event.target);
+      const targetIsNotInput   = event.target !== this._element;
+      console.log(targetIsOutside, targetIsInDocument, targetIsNotInput);
+      if (targetIsOutside && targetIsInDocument && targetIsNotInput)
         this.datepickerInstance.close();
     });
 
-    // close the datepicker on escape keydown events
+    // close the instance on escape keydown events
     this._element.addEventListener('keydown', event => {
       if (event.keyCode === KEYCODE_ESCAPE) {
         this.datepickerInstance.close();