Detect when filtering is complete

[Håkan]

Hi,

I have some custom filtering of the appoinments created as in your demos.
With this kind of code (some parts left out):

public void ApplyFilter()
       {
           this.OnPropertyChanged("AppointmentsFilter");
       }

       public Predicate<IAppointment> AppointmentsFilter
       {
           get
           {
               return this.Filter;
           }
       }

       private bool Filter(IAppointment appointment)
       {
           TimeScheduleShift shift = appointment as TimeScheduleShift;
           bool match = shift != null && this.FilterByShiftType(shift);
           return match;
       }

 private bool FilterByShiftType(TimeScheduleShift shift)
       {
           return this.SelectedShiftTypes.Count == 0 || this.SelectedShiftTypes.Contains(shift.ShiftTypeId);
       }

I want to know when the filtering is complete, because then I need to do some calculations on the visible appointments.
I can't add an event to the Filter method, because it will be called for every appointment.
And I can't just do the calculation after I have called ApplyFilter, because the filtering is async and not ready then.

Is there another way of knowing when the filtering is complete?

Regards,
Håkan

[Valeri Hristov]

Hello Håkan,

I am not aware of a way to determine when the filtering has finished. We are using a CollectionView internally in RadScheduleView, which is used for grouping and filtering and it does not provide notifications when certain task is finished.

Greetings,
Valeri Hristov
the Telerik team

[Håkan]

Hi Valerie.

I solved this by setting a counter to number of appointments in the Filter method.
And for each appoinment beeing filtered I subtract the counter.
And when counter is reaching 0, I raise an event.
Do you see any potentional problems with this?

public void ApplyFilter()
       {
           filterCounter = Appointments.Count;

           this.OnPropertyChanged("AppointmentsFilter");
       }

       public Predicate<IAppointment> AppointmentsFilter
       {
           get
           {
               return this.Filter;
           }
       }

       private bool Filter(IAppointment appointment)
       {
           TimeScheduleShift shift = appointment as TimeScheduleShift;
           bool match = shift != null && this.FilterByShiftType(shift) && this.FilterByEmployee(shift) && this.FilterByPreliminary(shift) &&
               this.FilterByStatusOpen(shift) && this.FilterByStatusAssigned(shift) &&
               this.FilterByUserStatusAccepted(shift) && this.FilterByUserStatusWanted(shift) && this.FilterByUserStatusUnwanted(shift) && this.FilterByUserStatusAbsence(shift);

           shift.IsVisible = match;

           filterCounter--;
           if (filterCounter == 0 && Filtered != null)
               Filtered(this, EventArgs.Empty);

           return match;
       }

Regards,
Håkan

[Rosi]

Hi Håkan,

i suggest you give it a try. If every appointment from Appointments collection goes through the Filter method everything should works as expected.

Kind regards,
Rosi
the Telerik team

[Håkan]

Hi.

Unfortunately this didn't always work.
In some cases all appointments are not passed through the Filter method, and then my event will never be raised.

I have solved it by a timer now.
The timer starts when the filter is initialized and for each time an appointment is passed through the Filter method, I restart the timer.
So the timer will be triggered for example 500 milliseconds after the last appoinment is filtered.
I will try with lower intervall to get it as responsive as possible...

But if you know of a better solution I would appreciate it.

Regards,
Håkan

[Yana]

Hi Håkan,

At the moment  we are not aware of a better solution.

Kind regards,
Yana
the Telerik team