DP44/enriched-partialglm/DTS Viewer/DTS.Viewer.Modules/DTS.Viewer.Navigation/ViewModel.md

source_files, generated_at, model, schema_version, sha256

source_files	generated_at	model	schema_version	sha256
DTS Viewer/DTS.Viewer.Modules/DTS.Viewer.Navigation/ViewModel/NavigationViewModel.cs	2026-04-16T11:19:33.784254+00:00	zai-org/GLM-5-FP8	1	17ac7f526470fc92

Documentation: NavigationViewModel

1. Purpose

NavigationViewModel is a ViewModel component responsible for managing the navigation UI region within the DTS Viewer application. It serves as a mediator between the INavigationView and the application's navigation system, handling notification and confirmation dialogs via Prism's interaction request patterns. The class inherits from BaseViewModel<INavigationViewModel> and implements INavigationViewModel, integrating with the Prism/Unity dependency injection and region management framework.

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2. Public Interface

Constructor

public NavigationViewModel(INavigationView view, IRegionManager regionManager, IEventAggregator eventAggregator, IUnityContainer unityContainer)

Initializes the navigation view model with its dependencies. Sets the view's DataContext to itself, creates NotificationRequest and ConfirmationRequest instances, and subscribes to the RaiseNotification event via the event aggregator.

Properties

Property	Signature	Description
NavigationView	INavigationView { get; private set; }	Holds the associated navigation view instance.
NotificationRequest	InteractionRequest<Notification> { get; private set; }	Interaction request for displaying notifications.
ConfirmationRequest	new InteractionRequest<Confirmation> { get; private set; }	Interaction request for displaying confirmations. Hides base member.
ContextNavigationRegion	object { get; set; }	Gets or sets the content of the NavigationRegion on the concrete NavigationView. Raises OnPropertyChanged on set.
HeaderInfo	string { get; }	Returns the constant string "NavigationRegion".
IsBusy	new bool { get; set; }	Throws NotImplementedException on both getter and setter. Hides base member.
IsDirty	new bool { get; }	Throws NotImplementedException on getter. Hides base member.
IsNavigationIncluded	new bool { get; set; }	Auto-property hiding base member.

Events

Event	Signature	Description
PropertyChanged	new event PropertyChangedEventHandler	Hides the base class event. Invoked via OnPropertyChanged.

Methods

Method	Signature	Description
Initialize	override void Initialize()	Empty override. No initialization logic.
Initialize	override void Initialize(object parameter)	Casts parameter to IBaseViewModel and assigns to private Parent field.
OnRaiseNotification	void OnRaiseNotification(NotificationContentEventArgs eventArgsWithTitle)	Private event handler. Converts NotificationContentEventArgs to NotificationContentEventArgsWithoutTitle and raises the NotificationRequest.

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3. Invariants

• NavigationView is assigned in the constructor and is expected to be non-null throughout the instance lifetime.
• The DataContext of NavigationView is always set to this (the ViewModel itself).
• NotificationRequest and ConfirmationRequest are initialized in the constructor and never reassigned.
• The RaiseNotification event subscription is established at construction time and remains active for the instance lifetime.
• ContextNavigationRegion property getter assumes NavigationView can be cast to the concrete NavigationView type and that NavigationRegion is non-null.

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4. Dependencies

This module depends on:

• DTS.Common.Base — BaseViewModel<T>, IBaseViewModel
• DTS.Common.Events — RaiseNotification (event), NotificationContentEventArgs
• DTS.Common.Interactivity — InteractionRequest<T>, Notification, Confirmation
• DTS.Common.Interface — INavigationViewModel, INavigationView
• Prism.Events — IEventAggregator
• Prism.Regions — IRegionManager
• Unity — IUnityContainer

Consumers:

• Not determinable from this source file alone. The class is public and designed for use by other modules in the DTS.Viewer application.

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5. Gotchas

1. Member hiding with new keyword: Multiple members (ConfirmationRequest, IsBusy, IsDirty, IsNavigationIncluded, PropertyChanged) use new to hide base class members. This can cause confusion when casting to base types or interfaces, as the hidden members will not be invoked.

2. NotImplementedException on IsBusy and IsDirty: Both properties throw NotImplementedException on access. Calling code must not attempt to read or write these properties.

3. Concrete type cast in ContextNavigationRegion: The property casts INavigationView NavigationView to the concrete NavigationView type to access NavigationRegion.Content. This breaks the abstraction provided by the interface and creates tight coupling to the concrete view implementation.

4. Unused private fields: Parent, EventAggregator, and UnityContainer are stored as private fields but Parent is only assigned (never read), and EventAggregator/UnityContainer are only used for subscription in the constructor. This may indicate incomplete implementation or dead code.

5. ReSharper suppression directives: The file contains multiple // ReSharper disable comments (CheckNamespace, NotAccessedField.Local, UnusedAutoPropertyAccessor.Local, AutoPropertyCanBeMadeGetOnly.Local), suggesting known code quality issues that have been suppressed rather than addressed.