command

According to my understanding of MVVM, it is a good practice to handle routed commands directly in the ViewModel. When a routed command is defined in a ViewModel as a RelayCommand (or DelegateCommand), it is easy to bind directly to the command like this: Command={Binding MyViewModelDefinedCommand}. Actually, for routed command that are defined outside of my ViewModel, I handle those commands in the Code behind of the View and forward calls to the ViewModel. But I find it awkward that I have to do so. It goes against recommended MVVM good practices. I think that there should be a more elegant

I have Menu in my app. I'm visualizing it using hierarchical data template: <MenuItem Header="Main menu" ItemsSource="{Binding ApplicationMenu}" > <MenuItem.ItemTemplate> <HierarchicalDataTemplate DataType="{x:Type tm:RMenuItem}" ItemsSource="{Binding Path=ChildrenItems}"> <MenuItem Header="{Binding Name}" Command="{Binding RunOperationCommand}" /> </HierarchicalDataTemplate> </MenuItem.ItemTemplate> </MenuItem> menu looks like as it should, but Command for each menu item is not fired! Even more - it is not bounded, which could be seen in debugger: get accessor of ICommand Property has been

As part of a diagnostics page I would like to have the user be able to run a "ping", ie an ordinary shell command to send ICMP_ECHO_REQUSTs to a certain IP and display the resuls dynamically in a div in the browser. The backend is Ruby/Rails. I'm past running the command on the server side and reading the output from the ping command. And I've been building web pages that periodically calls back to the server to update som parts of the page dynamically. But in this case there are three challenges: be able to have the ajax call back to an uri/url to find the process that runs the ping command

When creating an WPF application with the MVVM pattern, it seems I have to gather the necessary tools myself to even begin the most rudimentary event handling, e.g. AttachedBehaviors I get from here DelegateCommands I get from here Now I'm looking for some way to handle the ItemSelected event in a ComboBox and am getting suggestions of tricks and workarounds to do this (using a XAML trigger or have other elements bound to the selected item, etc.). Ok, I can go down this road, but it seems to be reinventing the wheel. It would be nice to just have an ItemSelected command that I can handle in my

Suppose I have User domain class and RegistrationCommand class. So when user is registering on website there are two steps for data validation: RegistrationCommand constraints validation. User domain object constrains validation. Controller action receive command object and pass it to view in a model after computing. So, I want to join domain objects' validation errors with command objects' errors and pass them as a part of command object. What is the best way to do that? I think the full answer is: if (!user.validate() || !user.save(true)) { if (user.errors.hasErrors()) { user.errors