Execute RaiseCanExecuteChanged from 'subclass' - wpf

Question

So I have the following setup:
PLANNING:
public class Planning : ViewModelBase
{
public Planning()
{
AddNewActivityCommand = new RelayCommand(AddActivity, CanAddActivity);
}
public ObservableCollection<PlanningItem> PlanningItems { get; set; }
public PlanningItem SelectedPlan { get; set; }
#region AddNewActivity
public RelayCommand AddNewActivityCommand { get; private set; }
private bool CanAddActivity()
{
if (!PlanningItems.Any())
{
return true;
}
if (string.IsNullOrEmpty(PlanningItems[PlanningItems.Count - 1].Activities) != true ||
PlanningItems[PlanningItems.Count - 1].DhpRepresentativeSelected != null)
{
return true;
}
return false;
}
private void AddActivity()
{
PlanningItems.Add(new PlanningItem());
AddNewActivityCommand.RaiseCanExecuteChanged();
}
#endregion
}
PLANNING ITEM:
public class PlanningItem : ViewModelBase
{
private string _activity;
public ObservableCollection<OutreachUser> DhpRepresentativeSource
{
get
{
var userSource = new ObservableCollection<OutreachUser>();
using (var context = new Outreach_Entities())
{
var query = from a in context.UserInfoes
join b in context.PersonalInfoes on a.UserIdentity equals b.PersonIdentity
join c in context.PersonalTitles on b.TitleLink equals c.TitleIdentity into cGroup
from c in cGroup.DefaultIfEmpty()
select new OutreachUser
{
PersonLink = a.UserIdentity,
Username = a.Username,
FirstName = b.FirstName,
MiddleInitial = b.MiddleInitial,
LastName = b.LastName
};
foreach (var result in query)
{
userSource.Add(result);
}
return userSource;
}
}
}
public OutreachUser DhpRepresentativeSelected { get; set; }
public DateTime PlanningDate { get; set; }
public TimeSpan PlanningStart { get; set; }
public TimeSpan PlanningEnd { get; set; }
public int PlanningTotalHours { get; set; }
public string Activities
{
get
{
return _activity;
}
set
{
_activity = value;
RaisePropertyChanged(nameof(Activities), "", _activity, true);
}
}
}
I have a ListBox bound to the PlanningItems Observable Collection.
I want to be able to add a new item to the list if the following criteria are met:
The Planning Items Collection is empty.
The last item in the Planning Items Collection has a DhpRepresentativeSelected that is not null.
The last item in the Planning Items Collection has some text in the Activities string.
The first item is easy enough because I call AddNewActivityCommand.RaiseCanExecuteChanged(); after I add a new item from an empty list.
Now I need to call the AddNewActivityCommand.RaiseCanExecuteChanged(); from within the PlanningItem ViewModel, but it does not have access rights to the command.

Answer 1

Clueless pointed me to the answer.
What I did was inside of my Planning ViewModel I created an internal Method that called the AddNewActivityCommand.RaiseCanExecuteChanged() method. I think called that method from within the PlanningItems ViewModel.