title: Filtering animals using wpf radiobuttons
body: <p>I am playing with a sample WPF application that is tiered in a Model-View-Presenter manner. The Model is a collection of Animals which is displayed in a view via binding to properties in a presenter class. The XAML has an items control that displays all the animals in a model. </p>
  
  <p>The model class has a boolean attribute called 'IsMammal'. I want to introduce a filter in the XAML in the form of a radio button group that filters the collection of animals based on the 'IsMammal' attribute. Selection of the radiobutton 'Mammals' updates the items control with all the Animals that have the 'IsMammal' value set to true and when the value is toggled to 'Non-Mammals', the display is updated with all animals that have that particular boolean set to false. The logic to do the filtering is extremely simple. What is troubling me is the placement of the logic. I don't want any logic embedded in the *.xaml.cs. I want the toggling of the radiobutton to trigger a logic in the presenter that tapers my animal collection to be rebound to the display.</p>
  
  <p>Some guidance here will be extremely appreciated.</p>
  
  <p>Thanks</p>