public EntityListViewModel(IEventAggregator eventAggregator, IEntityProvider entityProvider, TreeItemViewModelFactory treeItemViewModelFactory)
{
//assign event aggregator to local variable for later use
EA = eventAggregator;
EA.GetEvent <NewEntityRequestEvent>().Subscribe(NewEntityRequestEventExecute);
EA.GetEvent <DataLoadSuccessEvent>().Subscribe(DataLoadSuccessEventExecute);
EA.GetEvent <FilterRequestEvent>().Subscribe(FilterRequestEventExecute);
EA.GetEvent <UIUpdateRequestEvent>().Subscribe(UIUpdateRequestExecute);
TreeItemViewModelFactory = treeItemViewModelFactory;
EP = entityProvider;
TreeHeads = new ObservableCollection <OrganizationTreeItemViewModel>
{
//currently only uses the first head specified in the RTree, eventually plan to add multi head RTrees
//RTrees currently support multi heading, TreeHeads does not
TreeItemViewModelFactory.CreateOrganizationViewModel(null, EP.HeadEntities()[0])
};
RaisePropertyChanged(nameof(TreeHeads));
}
