I installed the update - but cannot find the variable in 

    void EditAppointment(SchedulerEditEventArgs args)
    {
     }

I hope this helps some people that are waiting for this feature.  This was critical for our business, so I had to figure out a workaround. I needed to go into the JavaScript to catch the events to handle the scheduler events.  In my case, I needed to catch the double click and right click(context menu) events on open time slots in the grid.  I started by adding some listeners to the Client\wwwroot\index.html scripts.  I have multiple pages that have schedules, so I centralized the script-- it can probably by added to the page with the scheduler if needed.

        function SetDotNetHelper(dotNetHelper) {
            window.dotNetHelper = dotNetHelper;
        }

       function attachContextMenu(parentClass) {
            window.setTimeout(function () {
                var schedulerSlotContainer = document.querySelector(parentClass + " .k-scheduler-body");
                if (schedulerSlotContainer) {
                    schedulerSlotContainer.addEventListener("contextmenu", e => {
                        if (e.target.className.indexOf("k-slot-cell") >= 0) {
                            // if time is empty, go to previous <div> row(s) to get it

                            var row = event.target.getAttribute("data-row-index")
                            var cell = event.target.getAttribute("data-cell-index")
                            var resource = event.target.getAttribute("data-resource-index")
                            window.dotNetHelper.invokeMethodAsync('OpenTimeSlotContext', row, cell, resource, e.clientX, e.clientY);
                        }
                        e.preventDefault();
                    });
                    schedulerSlotContainer.addEventListener("dblclick", e => {
                        if (e.target.className.indexOf("k-slot-cell") >= 0) {
                            // if time is empty, go to previous <div> row(s) to get it

                            var row = event.target.getAttribute("data-row-index")
                            var cell = event.target.getAttribute("data-cell-index")
                            var resource = event.target.getAttribute("data-resource-index")
                            window.dotNetHelper.invokeMethodAsync('OpenTimeSlotDoubleClick', row, cell, resource);
                        }
                        e.preventDefault();
                    });
                }
            });
        }

The next steps are in the page that contains the schedule.

Declare this as a variable for the the page.

        private DotNetObjectReference<EventCalendarBase> _dotNetHelper;

Add this code to OnAfterRenderAsync.

            if (!Loading) //Make sure intial loading is done.  Don't load javascript until schedule is displaying
            {
                await AttachContextMenu();
            }

The AttachContextMenu method.  (This process started with just the context menu and expanded to the double click later, so don't let the ContextMenu name discourage you.)  I had to reload the JavaScript when the view changed.  CurView is bound to the @bind-View of the scheduler.

        private async Task AttachContextMenu()
        {
            if (CurrView != _holdView)
            {
                await _js.InvokeVoidAsync("attachContextMenu", new[] { ".schedulerContainer " });
                _holdView = CurrView;
            }
        } 

You'll want a dispose as well.

        public void Dispose()
        {
            if (_dotNetHelper != null)
            {
                _dotNetHelper.Dispose();
            }
        }

Finally, here are the methods that are used when the context menu and double click methods are triggered.

        [JSInvokable]
        public void OpenTimeSlotDoubleClick(string Row, string Cell, string Resource)
        {
            GetContextInfo(Row, Cell, Resource);
            CreateNewEvent(SelectedSlotDateTime, SelectedSlotFacilityId); //Sets up and displays our custom edit form
            StateHasChanged();
        }

        [JSInvokable]
        public async Task OpenTimeSlotContext(string Row, string Cell, string Resource, int ClientX, int ClientY)
        {
            GetContextInfo(Row, Cell, Resource);
            await OpenContextMenuRef.ShowAsync(ClientX, ClientY); //Displays the context menu
        }

        public void GetContextInfo(string Row, string Cell, string Resource)
        {
            DateTime workingDate = SchedulerRef.Date;
            DateTime workingTime = SchedulerRef.Date;
            switch (SchedulerRef.View)
            {
                case SchedulerView.Day:
                    // date already set
                    SchedulerDayView dayView = (SchedulerDayView)SchedulerRef.SelectedView;
                    workingTime = CalculateSelectedTime(SchedulerRef.ShowWorkHours ? dayView.WorkDayStart : dayView.StartTime, dayView.SlotDuration, dayView.SlotDivisions, int.Parse(Row));
                    SelectedSlotDateTime = new DateTime(workingDate.Year, workingDate.Month, workingDate.Day, workingTime.Hour, workingTime.Minute, 0);
                    break;
                case SchedulerView.Week:
                    SchedulerWeekView vw = (SchedulerWeekView)SchedulerRef.SelectedView;

                    workingDate = CalculateWeekDate(int.Parse(Cell), SchedulerRef.Date);
                    workingTime = CalculateSelectedTime(SchedulerRef.ShowWorkHours ? vw.WorkDayStart : vw.StartTime, vw.SlotDuration, vw.SlotDivisions, int.Parse(Row));
                    SelectedSlotDateTime = new DateTime(workingDate.Year, workingDate.Month, workingDate.Day, workingTime.Hour, workingTime.Minute, 0);
                    break;
                case SchedulerView.MultiDay:
                    SchedulerMultiDayView multiDayView = (SchedulerMultiDayView)SchedulerRef.SelectedView;
                    workingDate = SchedulerRef.Date.AddDays(int.Parse(Cell));
                    workingTime = CalculateSelectedTime(SchedulerRef.ShowWorkHours ? multiDayView.WorkDayStart : multiDayView.StartTime, multiDayView.SlotDuration, multiDayView.SlotDivisions, int.Parse(Row));
                    SelectedSlotDateTime = new DateTime(workingDate.Year, workingDate.Month, workingDate.Day, workingTime.Hour, workingTime.Minute, 0);
                    break;
                case SchedulerView.Month:
                    break;
            }
            SelectedSlotFacilityId = long.Parse(FacilityResourceList[int.Parse(Resource)].Value);
        }

        private static DateTime CalculateWeekDate(int Cell, DateTime WeekDate)
        {
            if (WeekDate.DayOfWeek == DayOfWeek.Sunday)
            {
                return WeekDate;
            }
            for (int i = -1; i > -7; i--)
            {
                DateTime check = WeekDate.AddDays(i);
                if (check.DayOfWeek == DayOfWeek.Sunday)
                {
                    return check.AddDays(Cell);
                }
            }
            return WeekDate;
        }

        private static DateTime CalculateSelectedTime(DateTime StartTime, int SlotDuration, int SlotDivisions, int Row)
        {
            return StartTime.AddMinutes(Row * (SlotDuration / SlotDivisions));
        }

Hopefully someone can use this as a template to help move them down the road.

Rob

Hi Telerik Team

We need here a solution, otherwise our customers will be unhappy. 

When do you think, we will get an update ? 

BR

ABDULLAH

CEO

same here,
in SchedulerEditEventArgs, Start, IsAllDay, ... is there, but NOT the Group ....


uuuppss...

Hi Telerik

Can you give us an Feedback, when the feature will be implemented ?

Thanks

Hi,

This is an important feature, cause if I want to have custom dialog to create appointment event in grouping resource then currently I can't do that!

Thanks,

Thomas