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BLAZMVVM0018: NotifyPropertyChangedFor Analyzer

Diagnostic Information

  • Diagnostic ID: BLAZMVVM0018
  • Category: Blazing.Mvvm
  • Severity: Info
  • Title: Missing NotifyPropertyChangedFor attribute

Description

Detects computed/read-only properties that depend on observable properties but lack [NotifyPropertyChangedFor] attribute to notify UI when dependencies change.

Examples

❌ Incorrect

public partial class PersonViewModel : ViewModelBase
{
    [ObservableProperty]
    private string _firstName; // BLAZMVVM0018: should notify FullName

    [ObservableProperty]
    private string _lastName; // BLAZMVVM0018: should notify FullName

    public string FullName => $"{FirstName} {LastName}";
    // FullName won't update when FirstName/LastName change!
}

✅ Correct

public partial class PersonViewModel : ViewModelBase
{
    [ObservableProperty]
    [NotifyPropertyChangedFor(nameof(FullName))]
    private string _firstName;

    [ObservableProperty]
    [NotifyPropertyChangedFor(nameof(FullName))]
    private string _lastName;

    public string FullName => $"{FirstName} {LastName}";
    // FullName updates automatically when dependencies change
}

Benefits

  • UI automatically reflects computed property changes
  • No manual StateHasChanged() calls needed
  • Declarative dependency tracking
  • Better performance with targeted updates
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