fix: Patch FullCalendar to show single day events (#4757)

Author: iamareebjamal

app/routes/events/view/scheduler.js

@@ -1,4 +1,43 @@
 import Route from '@ember/routing/route';
+import $ from 'jquery';
+
+// TODO(Areeb): Remove once upgraded
+// Workaround for https://github.com/fossasia/open-event-frontend/issues/4729
+function patchFullCalendar() {
+  if (!window?.FullCalendar) {return}
+  window.FullCalendar.EventRenderer.prototype.renderFgSegEls = function(segs, disableResizing) {
+    let _this = this;
+    if (disableResizing === void 0) { disableResizing = false }
+    let hasEventRenderHandlers = this.view.hasPublicHandlers('eventRender');
+    let html = '';
+    let renderedSegs = [];
+    let i;
+    if (segs.length) {
+      // build a large concatenation of event segment HTML
+      for (i = 0; i < segs.length; i++) {
+        this.beforeFgSegHtml(segs[i]);
+        html += this.fgSegHtml(segs[i], disableResizing);
+      }
+      // Grab individual elements from the combined HTML string. Use each as the default rendering.
+      // Then, compute the 'el' for each segment. An el might be null if the eventRender callback returned false.
+      $(html).each(function(i, node) {
+        let seg = segs[i];
+        let el = $(node);
+        // Areeb: seg is undefined for single day events as i > seg.length due to some logical error
+        if (seg && hasEventRenderHandlers) { // Areeb: Added `seg && `
+          el = _this.filterEventRenderEl(seg.footprint, el);
+        }
+        if (seg && el) { // Areeb: Added `seg && `
+          el.data('fc-seg', seg); // used by handlers
+          seg.el = el;
+          renderedSegs.push(seg);
+        }
+      });
+    }
+    return renderedSegs;
+  };
+}
+
 export default Route.extend({
   titleToken() {
     return this.l10n.t('Scheduler');
@@ -9,6 +48,7 @@ export default Route.extend({
     }
   },
   async model() {
+    patchFullCalendar();
     let unscheduledFilterOptions = [
       {
         and: [