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AR Payment Reversal Navigation Implementation

Overview​

The AR Payment Reversal dashboard implements the Navigation Architecture Pattern with specific workflows optimized for financial transaction reversal processes.

MainView (Container)
    ├── ArReversePaymentQueueView (Default/Home)
    │   ├── ArReversePaymentAddPaymentView (Add payments to queue)
    │   │   └── CustomerSelectionDialogView (Modal selection)
    │   └── ArReversePaymentCompletionView (Post-processing results)
    └── SettingsDialogView (Configuration modal)

Implementation Details​

MainViewModel Configuration​

The MainViewModel serves as the navigation host with specific configurations for payment reversal:

// MepApps.Dash.Ar.Maint.PaymentReversal/ViewModels/MainViewModel.cs (Lines 5-144)
public class MainViewModel : BaseRouteableViewModel
{
    private readonly BasicMepNavigationUiHostNotificator _navigationUiHostNotificator;
    
    public MainViewModel(...)
    {
        _navigationUiHostNotificator.MainContentChanged += (sender, e) => SetMainContent(sender);
        this.Title = "AR Payment Reversal";
    }
    
    public void SetMainContent(object content)
    {
        Dispatcher.CurrentDispatcher.Invoke(() =>
        {
            var navigatedFromContent = mainContent;
            MainContent = content;
            
            if (navigatedFromContent is INavigationTarget)                
                ((INavigationTarget) navigatedFromContent)?.NavigatedFrom();
            
            if (content is INavigationTarget)
                ((INavigationTarget) content)?.NavigatedTo();
        });
    }
}

Queue-Based Navigation Pattern​

The dashboard implements a queue-centric navigation pattern:

// MepApps.Dash.Ar.Maint.PaymentReversal/ViewModels/ArReversePaymentQueueViewModel.cs (Lines 259-272)
public event EventHandler<EventArgs> NavigateToAddPayment;

private async Task AddPayment()
{
    IsLoading = true;
    await Task.Delay(300).ConfigureAwait(true);
    NavigateToAddPayment?.Invoke(this, new EventArgs());
}

Property-Based Navigation Triggers​

Navigation is triggered based on property changes specific to payment reversal workflow:

// MepApps.Dash.Ar.Maint.PaymentReversal/ViewModels/ArReversePaymentQueueViewModel.cs (Lines 79-95)
private async void ArReversePaymentQueueViewModel_PropertyChanged(object sender, PropertyChangedEventArgs e)
{
    switch (e.PropertyName)
    {
        case "ReversePaymentQueueHeaders":
            await ReversePaymentQueueHeadersChanged().ConfigureAwait(true);
            break;              
    }
}

Payment Queue Validation​

Navigation guards ensure data integrity before allowing transitions:

// MepApps.Dash.Ar.Maint.PaymentReversal/ViewModels/ArReversePaymentQueueViewModel.cs (Lines 341-346)
if (ReversePaymentQueueHeaders == null || !ReversePaymentQueueHeaders.Any())
    return;

IsLoading = true;
// Proceed with navigation

Thread Safety​

All navigation operations are synchronized with the UI thread:

// MepApps.Dash.Ar.Maint.PaymentReversal/ViewModels/MainViewModel.cs (Lines 84-105)
Dispatcher.CurrentDispatcher.Invoke(() =>
{
    if (_logger.IsEnabled(LogLevel.Trace))
        _logger.LogTrace("CHANGING MAIN CONTENT to {ContentIsNull}, {NameOfContent}", 
            content == null, content?.GetType().Name);
    
    // Navigation logic here
});

Memory Management​

The dashboard implements proper disposal patterns during navigation:

// MepApps.Dash.Ar.Maint.PaymentReversal/ViewModels/MainViewModel.cs (Lines 136-144)
private bool disposed = false;
public void Dispose()
{
    if (!disposed)
    {
        disposed = true;
        // Cleanup logic
    }
}

Error Handling​

Comprehensive error handling for navigation failures:

// MepApps.Dash.Ar.Maint.PaymentReversal/ViewModels/MainViewModel.cs (Lines 28-33)
catch (Exception ex)
{
    _logger.LogError(ex, "Failed to initialize MainViewModel");
    throw;
}

Dashboard-Specific Features​

1. Payment Queue Management​

  • Maintains navigation state across payment queue operations
  • Preserves selected payments during navigation
  • Handles batch processing navigation flows

2. Customer Selection Integration​

  • Modal dialog navigation for customer selection
  • Maintains parent context during modal operations
  • Returns selected customer data to calling view

3. Completion View Navigation​

  • Displays processing results after reversal
  • Provides navigation back to queue with state reset
  • Maintains audit trail during navigation

Performance Optimizations​

Loading Indicators​

private async Task NavigateWithLoading()
{
    IsLoading = true;
    await Task.Delay(300).ConfigureAwait(true); // Smooth transition
    NavigateToTarget?.Invoke(this, new EventArgs());
    IsLoading = false;
}

Lazy View Loading​

Views are instantiated only when first accessed to improve startup performance.

Summary​

The AR Payment Reversal dashboard's navigation implementation extends the base MepDash navigation patterns with specific features for financial transaction workflows. The queue-centric design, combined with proper state management and error handling, ensures reliable navigation through complex payment reversal processes.