INotifyPropertyChanged

Most modern UI applications rely on binding data classes to UI classes. The INotifyPropertyChanged interface is the standard way to achieve this. However, implementing this interface manually can be cumbersome and error-prone, particularly when dealing with a large number of properties.

Thanks to Metalama’s Observable aspect from the Metalama.Patterns.Observability open-source package, you can implement the INotifyPropertyChanged interface automatically. The plumbing code is generated on-the-fly when you compile, so your source code remains clean and concise.

Metalama.Patterns.Observability is a production-ready, professionally supported, and open-source aspect library.

Available for all UI frameworks

Example

In the following code, the [Observable] aspect is applied to two classes: Customer (the model class) and CustomerViewModel.

// THAT'S ALL. These classes implement INotifyPropertyChanged
// Thanks to the [Observable] aspect.

[Observable]
public partial class Customer
{
    public string FirstName { get; set; }
    public string LastName { get; set; }
}

[Observable]
public partial class CustomerViewModel
{
    // YES. This property can change.
    public Customer Customer { get; set; }

    // YES. This property depends on a property of a property.
    public string FullName
        => $"{this.Customer.FirstName} {this.Customer.LastName}";
}

Benefits

  • Boost your productivity. Eliminate 95% of the INotifyPropertyChanged repetitive code, as most cases are handled automatically.
  • Avoid errors. Never forget to call OnPropertyChanged again.
  • Keep your code clean and concise. Your business logic is no longer hidden behind the observability plumbing.

Features

  • Idiomatically C#: Metalama works with your code, not against it.
  • Recursive code analysis algorithm that detects dependencies of properties on fields and other properties within.
  • Support for complex dependencies, such as properties depending on properties of child objects or of the base class.
  • Customizable. Take control when needed to handle corner cases.
  • Compatible with MVVM frameworks.

Resources