Databases
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PO
 

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    <p>Three VMs is the right way in your scenario. I suggest you to build a Parent/Child relation between you VMs. Since the the MainVM holds the ItemList, this is the place, where FilterChanges are applied. The FilterEditVM only receives the filter changes and than calls the MainVM, that it has to re-apply the filters. </p> <p>The structure would be something like this:</p> <pre><code>public class WelcomePageVM { public WelcomePageVM() { this.FilterEditPageVM = new FilterEditPageVM(this); this.MainItemsVM = new MainItemsVM(this); } public FilterEditPageVM FilterEditPageVM { get; private set; } public MainItemsVM MainItemsVM { get; private set; } public void SetInitialFilter1(object filter) { // the initial filter this.FilterEditPageVM.Filter1Value = filter; this.MainItemsVM.ApplyFilters(); } } public class FilterEditPageVM : ChildViewModelBase&lt;WelcomePageVM&gt; { public FilterEditPageVM(WelcomePageVM parent) : base(parent) { } public object Filter1Value { get; set; } public object Filter2Value { get; set; } public object Filter3Value { get; set; } public object Filter4Value { get; set; } public void FinishFilterChange() { this.Parent.MainItemsVM.ApplyFilters(); } } public class MainItemsVM : ChildViewModelBase&lt;WelcomePageVM&gt; { public MainItemsVM(WelcomePageVM parent) : base(parent) { } public List&lt;object&gt; ItemList { get; set; } public void ApplyFilters() { // filter apply logic } } public abstract class ChildViewModelBase&lt;T&gt; { T _parent; public ChildViewModelBase(T parent) { this._parent = parent; } public T Parent { get { return _parent; } } } </code></pre> <p>Here you can access all viewmodels, which is okay because you stay in the "controller" level.</p>
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    1. POMVVM - Deciding which ViewModel is responsible for what
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    1. USJanW
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    1. COP.S: Added FinishFilterChange() to FilterEditVM
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    2. COThanks. I can see all that working but it just seems wrong that the little old WelcomePage is the Parent but I think that is me getting caught up in some misunderstanding and misapplication of semantics. Have you put WelcomePage as the Parent because it is the first screen(view) loaded?
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      1. USPat Long - Munkii Yebee
    3. COExactly. Of course, with the above pattern you can freely chose your root. But I recommend to use the first View as your root, because its sensefull, if your controller model represents the ways you can follow on the GUI. If you review your App after some time, it is easier to understand the workflow. If you dont like your welcome page as root, i suggest you to build another real RootView, in which you switch your three other views. This particular RootView will then possess all three above ViewModels.
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Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

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