PRISM and WPF how to add a module on demand

Question

I have a set of tabs in my shell window and one main region whicxh is a contentcontrol. I also have four modules that I want to load on demand when a certain tab is selected. So when tab1 is selected I want to load moduleA, when tab2 is selected I want to load ModuleB, etc. The first module loads on when the application starts. The problem is that when I change the tab nothing happens. There are no errors tough. I'm using this version of prism Composite Application Guidance for WPF and Silverlight - October 2009.

I tried this approach:

Shell:

 public partial class Shell : RibbonWindow, IShellView
    {
        private readonly IRegionManager regionManager;
        private readonly IModuleManager moduleManager;

    public Shell(IModuleManager moduleManager)
    {
        this.moduleManager = moduleManager;
        InitializeComponent();

    }

    public void ShowView()
    {
        this.Show();
    }



    private void onTabSelection(object sender, RoutedEventArgs e)
        {
                 this.moduleManager.LoadModule("ModuleB");
        }
}

Bootstrapper:

  public partial class MyBootstrapper : UnityBootstrapper
    {
        protected override IModuleCatalog GetModuleCatalog()
        {
            var catalog = new ModuleCatalog();
            catalog.AddModule(typeof(ModuleA)).AddModule(typeof(ModuleB));

        return catalog;
    }

    protected override void ConfigureContainer()
    {
        Container.RegisterType<IShellView, Shell>();

        base.ConfigureContainer();
    }



    protected override DependencyObject CreateShell()
    {
        ShellPresenter presenter = Container.Resolve<ShellPresenter>();
        IShellView view = presenter.View;

        view.ShowView();

        return view as DependencyObject;
    }

}

And moduleB that I want to be able to load on demand (I used to use this commented line that's why I left it here):

[Module(ModuleName = "ModuleB", OnDemand = true)]
public class ModuleB : IModule
{  

    private readonly IUnityContainer _container;
    private readonly IRegionManager _regionManager;

    public ModuleB(IUnityContainer container, IRegionManager regionManager)
    {
        _container = container;
        _regionManager = regionManager;
    }
    public void Initialize() {

        _regionManager.Regions["MainRegion"].Add(new ModuleBView());
        this.RegisterViewsAndServices();

      //  this._regionManager.RegisterViewWithRegion(RegionNames.MainRegion, () => _container.Resolve<MissionProfileView>());
    }
    protected void RegisterViewsAndServices()
    {
        _container.RegisterType<Modules.ModuleBView>();
    }
}

What am I doing wrong here? How should I proceed?

Answer 1

i am successfully using ondemand loading of modules. in my scenario, i load them after the user logs in.

As a sanity check with your project, ensure that your ModuleB.dll is in the same directory as your shell/application. ( for instance make sure it gets copied to the debug directory if you are in debug mode ).

I have the module name and the module dll named the same, i am not sure if this is a requirement, but its the convention that i have stuck with.

my bootstrappers CreateModuleCatalog is very simple

protected override IModuleCatalog CreateModuleCatalog()
{
    ModuleCatalog catalog = new ConfigurationModuleCatalog();
    return catalog;

}

the modules are listed in my app.config file

<modules>
    <module assemblyFile="PatronModule.dll" moduleType="PatronModule.PatronModuleDefinition, PatronModule" moduleName="PatronModule" startupLoaded="false" />
</modules>

then when i load the modules i use this code

    IModuleManager moduleManager = _container.Resolve<IModuleManager>();
    ModulesConfigurationSection modules = ConfigurationManager.GetSection("modules") as ModulesConfigurationSection;
    foreach (ModuleConfigurationElement module in modules.Modules)
        moduleManager.LoadModule(module.ModuleName);

The loading of modules has to happen on the GUI thread, so if required you need to use the dispatcher to do the loading ( this is the line i use for it )

Application.Current.Dispatcher.BeginInvoke(DispatcherPriority.ContextIdle, new Action(() => { LoadModulesOnGuiThread(); }));

hope this helps