Data vs Representation

• Create a custom data type in python. Create methods to represent the logic side of the application

  class AccessLevel(object):
  	def __init__(self, name):
  		self.name = name
  
  class Employee(object):
  	def __init__(self, name, age, access_levels):
  		self.name = name
  		self.age = age
  		self.access_levels = access_levels
  	
  
  def get_employees():
  	pass
  

• Define ViewModels for data

  # define VM for employee and resolve the image file into a bitmapimage for WPF
  # cleanup the casing for name in VM as another example why we might need VMs
  class EmployeeVM(object):
  	pass
  

• Define a ViewModel for application. List of employees and the selected employee information

  • List control to select employee from the list and show info (Bind list SelectedItem → card DataContext with no convertors)

  • Beautify the employee list and card. Use templating to show employee levels as tags with colors.

    <DataTemplate.Triggers>
        <DataTrigger Binding="{Binding}" Value="TS">
            <Setter TargetName="itemborder" Property="Background" Value="Black" />
        </DataTrigger>
        <DataTrigger Binding="{Binding}" Value="GAMMA">
            <Setter TargetName="itemborder" Property="Background" Value="Red" />
        </DataTrigger>
    </DataTemplate.Triggers>
    

    Use templating to create a list of employee photos. Card shows info for each selected employee

    <ItemsPanelTemplate>
        <WrapPanel IsItemsHost="True"/>
    </ItemsPanelTemplate>
    
    <ControlTemplate>
        <Border VerticalAlignment="Center">
            <Image Height="100" Source="{Binding item}" VerticalAlignment="Center" HorizontalAlignment="Center"/>
        </Border>
    </ControlTemplate>
    

• Implement one-way and two-way reactivity

  class Reactive(ComponentModel.INotifyPropertyChanged):
      """WPF property updator base mixin"""
      PropertyChanged, _propertyChangedCaller = pyevent.make_event()
  
      def add_PropertyChanged(self, value):
          self.PropertyChanged += value
  
      def remove_PropertyChanged(self, value):
          self.PropertyChanged -= value
  
      def OnPropertyChanged(self, prop_name):
          if self._propertyChangedCaller:
              args = ComponentModel.PropertyChangedEventArgs(prop_name)
              self._propertyChangedCaller(self, args)
  

• Use pyrevit.forms to simplify reactivity