How to use FsXaml's CommandDependecy/(ies)

Question

Here is what I have done using FsXaml

type MainViewModel() as self = 
inherit ViewModelBase() 

    let listOfData = self.Factory.Backing(<@self.ListOfData@>, 0 :> obj)
    let selectedId = self.Factory.Backing(<@self.SelectedId@>, 0)

    member x.SelectedId with get() = selectedId.Value 
                        and set value = selectedId.Value <- value;
                                        x.ListOfData <- returnPrice(value) :> obj        
    member x.StockList with get() = stockList
    member x.ListOfData with get() = listOfData.Value and set value = listOfData.Value <- value

and in xaml

<ComboBox Grid.Row="1" ItemsSource="{Binding StockList}" 
              DisplayMemberPath="Code" 
              SelectedValuePath="Id" SelectedValue="{Binding SelectedId}"/>
<DataGrid Grid.Row="2" ItemsSource="{Binding ListOfData}"/>

How can I use command dependecy of ViewModule to set x.ListOfData instead of calling returnPrice(value) in setter of x.SelectedId?

I assume you want to use `self.DependencyTracker.AddPropertyDependencies`. — FoggyFinder, Nov 22 '16 at 22:34
Please write [MCVE](http://stackoverflow.com/help/mcve) to understand exactly what you want to do. — FoggyFinder, Nov 22 '16 at 22:42

score 3 · Answer 1 · answered Nov 23 '16 at 04:53

3

You assumed it right @Foggy Finder. I have replaced the code to -

let selectedId = self.Factory.Backing(<@self.SelectedId@>, 0)  

do
    self.DependencyTracker.AddPropertyDependency(<@self.ListOfData@>,<@self.SelectedId@>)

member x.SelectedId with get() = selectedId.Value and set value = selectedId.Value <- value;
member x.StockList with get() = stockList
member x.ListOfData with get() = returnPrice(self.SelectedId)

and it works!

What is the purpose of self.DependencyTracker.AddCommandDependency() and How to use it?

answered Nov 23 '16 at 04:53

1

never used this function. But the purpose is clear from the name. – FoggyFinder Nov 23 '16 at 09:56
1

That kind of belongs in a separate question - but in general, it's something you don't (normally) need to use yourself. It works like the property depednencies, but for teh canexecute of a command. Normally, when you create the command, you just include it in the dependent expressions, and the framework wires that up for you. – Reed Copsey Nov 23 '16 at 20:47
Thanks @ReedCopsey for your comment. Can you please suggest me some site/blog/video link as starter's guide to get idea about developing ASP.NET MVC application using F#? – Nov 24 '16 at 05:36
@emonhaque I'd recommend joining the F# software foundation, and asking in the Web channel of their slack team... likely will get the best answer. – Reed Copsey Nov 24 '16 at 05:38
@ReedCopsey Thanks once again. FsMvc5 is the right one for me. – Nov 24 '16 at 07:16

How to use FsXaml's CommandDependecy/(ies)

1 Answers1