Question

I am working with a team on LoB application. We would like to have a dynamic Menu control, which creates the menu based on the logged in user profile. In previous development scenarios (namely ASP.NET) we use to iterate through data which describes collection and generate MenuItem dynamically. In MVVM how would I do this? Can I separate XAML view from ViewModel which describes menu elements?

Solution:

With inputs from commentators I were able to bind Menu dynamically with the data from ViewModel. This article was of great help too.

XAML:

<HierarchicalDataTemplate DataType="{x:Type self:Menu}" ItemsSource="{Binding Path=Children, UpdateSourceTrigger=PropertyChanged}">
    <ContentPresenter Content="{Binding Path=MenuText}" RecognizesAccessKey="True"/>
</HierarchicalDataTemplate>

[...]

<Menu Height="21" Margin="0" Name="mainMenu" VerticalAlignment="Top" HorizontalAlignment="Stretch" 
      ItemsSource="{Binding Path=MenuItems, UpdateSourceTrigger=PropertyChanged}" ItemContainerStyle="{StaticResource TopMenuItems}">
    <Menu.Background>
        <ImageBrush ImageSource="/Wpf.Modules;component/Images/MenuBg.jpg" />
    </Menu.Background>
</Menu>

Menu data class:

public class Menu : ViewModelBase
{
    public Menu()
    {
        IsEnabled = true;
        Children = new List<Menu>();
    }

    #region [ Menu Properties ]

    private bool _isEnabled;
    private string _menuText;
    private ICommand _command;
    private IList<Menu> _children;

    public string MenuText
    {
        get { return _menuText; }
        set
        {
            _menuText = value;
            base.OnPropertyChanged("MenuText");
        }
    }

    public bool IsEnabled
    {
        get { return _isEnabled; }
        set
        {
            _isEnabled = value;
            base.OnPropertyChanged("IsEnabled");
        }
    }

    public ICommand Command
    {
        get { return _command; }
        set
        {
            _command = value;
            base.OnPropertyChanged("Command");
        }
    }

    public IList<Menu> Children
    {
        get { return _children; }
        set
        {
            _children = value;
        }
    }

    #endregion
}

Answer 1

Try something like this:

public class MenuItemViewModel
{
    public MenuItemViewModel()
    {
        this.MenuItems = new List<MenuItemViewModel>();
    }

    public string Text { get; set; }

    public IList<MenuItemViewModel> MenuItems { get; private set; }
}

Assume that your DataContext has a property called MenuItems which is a list of MenuItemViewModel. Something like this should work, then:

<Window x:Class="WpfApplication1.Window1"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:self="clr-namespace:WpfApplication1"
        Title="Window1" Height="300" Width="300">
    <Window.Resources>
        <HierarchicalDataTemplate DataType="{x:Type self:MenuItemViewModel}"
                                  ItemsSource="{Binding Path=MenuItems}">
            <ContentPresenter Content="{Binding Path=Text}" />
        </HierarchicalDataTemplate>
    </Window.Resources>
    <DockPanel>
        <Menu DockPanel.Dock="Top" ItemsSource="{Binding Path=MenuItems}" />
        <Grid />
    </DockPanel>
</Window>