RSCG – CommunityToolkit.Mvvm

Shows how to implement INotifyPropertyChanged,ObservableProperty and RelayCommand

Unfortunately,not yet a separate package just for those.

Also,this show that RSCG could generate multiple partial declarations

This is how you can use CommunityToolkit.Mvvm .

The code that you start with is

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>net7.0</TargetFramework>
    <ImplicitUsings>enable</ImplicitUsings>
    <Nullable>enable</Nullable>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="CommunityToolkit.Mvvm" Version="8.2.0" />
  </ItemGroup>
	<PropertyGroup>
		<EmitCompilerGeneratedFiles>true</EmitCompilerGeneratedFiles>
		<CompilerGeneratedFilesOutputPath>$(BaseIntermediateOutputPath)\GX</CompilerGeneratedFilesOutputPath>
	</PropertyGroup>
</Project>

The code that you will use is

// See https://aka.ms/new-console-template for more information
using test;

Console.WriteLine("Hello,World!");

MyViewModel myViewModel = new();
myViewModel.Name = "Andrei";
var x=myViewModel.SayHelloCommand;

using CommunityToolkit.Mvvm.ComponentModel;
using CommunityToolkit.Mvvm.Input;

namespace test;

[INotifyPropertyChanged]
public partial class MyViewModel 
{
    [ObservableProperty]
    private string? name;

    [RelayCommand]
    private void SayHello()
    {
        Console.WriteLine("Hello");
    }
}

The code that is generated is

// <auto-generated/>
#pragma warning disable
#nullable enable
namespace test
{
    /// <inheritdoc/>
    partial class MyViewModel : global::System.ComponentModel.INotifyPropertyChanged
    {
        /// <inheritdoc cref = "global::System.ComponentModel.INotifyPropertyChanged.PropertyChanged"/>
        [global::System.CodeDom.Compiler.GeneratedCode("CommunityToolkit.Mvvm.SourceGenerators.INotifyPropertyChangedGenerator","8.2.0.0")]
        [global::System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
        public event global::System.ComponentModel.PropertyChangedEventHandler? PropertyChanged;
        /// <summary>
        /// Raises the <see cref = "PropertyChanged"/> event.
        /// </summary>
        /// <param name = "e">The input <see cref = "global::System.ComponentModel.PropertyChangedEventArgs"/> instance.</param>
        [global::System.CodeDom.Compiler.GeneratedCode("CommunityToolkit.Mvvm.SourceGenerators.INotifyPropertyChangedGenerator","8.2.0.0")]
        [global::System.Diagnostics.DebuggerNonUserCode]
        [global::System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
        protected virtual void OnPropertyChanged(global::System.ComponentModel.PropertyChangedEventArgs e)
        {
            PropertyChanged?.Invoke(this,e);
        }

        /// <summary>
        /// Raises the <see cref = "PropertyChanged"/> event.
        /// </summary>
        /// <param name = "propertyName">(optional) The name of the property that changed.</param>
        [global::System.CodeDom.Compiler.GeneratedCode("CommunityToolkit.Mvvm.SourceGenerators.INotifyPropertyChangedGenerator","8.2.0.0")]
        [global::System.Diagnostics.DebuggerNonUserCode]
        [global::System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
        protected void OnPropertyChanged([global::System.Runtime.CompilerServices.CallerMemberName] string? propertyName = null)
        {
            OnPropertyChanged(new global::System.ComponentModel.PropertyChangedEventArgs(propertyName));
        }

        /// <summary>
        /// Compares the current and new values for a given property. If the value has changed,updates
        /// the property with the new value,then raises the <see cref = "PropertyChanged"/> event.
        /// </summary>
        /// <typeparam name = "T">The type of the property that changed.</typeparam>
        /// <param name = "field">The field storing the property's value.</param>
        /// <param name = "newValue">The property's value after the change occurred.</param>
        /// <param name = "propertyName">(optional) The name of the property that changed.</param>
        /// <returns><see langword="true"/> if the property was changed,<see langword="false"/> otherwise.</returns>
        /// <remarks>
        /// The <see cref = "PropertyChanged"/> event is not raised if the current and new value for the target property are the same.
        /// </remarks>
        [global::System.CodeDom.Compiler.GeneratedCode("CommunityToolkit.Mvvm.SourceGenerators.INotifyPropertyChangedGenerator","8.2.0.0")]
        [global::System.Diagnostics.DebuggerNonUserCode]
        [global::System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
        protected bool SetProperty<T>([global::System.Diagnostics.CodeAnalysis.NotNullIfNotNull("newValue")] ref T field,T newValue,[global::System.Runtime.CompilerServices.CallerMemberName] string? propertyName = null)
        {
            if (global::System.Collections.Generic.EqualityComparer<T>.Default.Equals(field,newValue))
            {
                return false;
            }

            field = newValue;
            OnPropertyChanged(propertyName);
            return true;
        }

        /// <summary>
        /// Compares the current and new values for a given property. If the value has changed,updates
        /// the property with the new value,then raises the <see cref = "PropertyChanged"/> event.
        /// See additional notes about this overload in <see cref = "SetProperty{T}(ref T,T,string)"/>.
        /// </summary>
        /// <typeparam name = "T">The type of the property that changed.</typeparam>
        /// <param name = "field">The field storing the property's value.</param>
        /// <param name = "newValue">The property's value after the change occurred.</param>
        /// <param name = "comparer">The <see cref = "global::System.Collections.Generic.IEqualityComparer{T}"/> instance to use to compare the input values.</param>
        /// <param name = "propertyName">(optional) The name of the property that changed.</param>
        /// <returns><see langword="true"/> if the property was changed,<see langword="false"/> otherwise.</returns>
        [global::System.CodeDom.Compiler.GeneratedCode("CommunityToolkit.Mvvm.SourceGenerators.INotifyPropertyChangedGenerator","8.2.0.0")]
        [global::System.Diagnostics.DebuggerNonUserCode]
        [global::System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
        protected bool SetProperty<T>([global::System.Diagnostics.CodeAnalysis.NotNullIfNotNull("newValue")] ref T field,T newValue,global::System.Collections.Generic.IEqualityComparer<T> comparer,[global::System.Runtime.CompilerServices.CallerMemberName] string? propertyName = null)
        {
            if (comparer.Equals(field,newValue))
            {
                return false;
            }

            field = newValue;
            OnPropertyChanged(propertyName);
            return true;
        }

        /// <summary>
        /// Compares the current and new values for a given property. If the value has changed,updates
        /// the property with the new value,then raises the <see cref = "PropertyChanged"/> event.
        /// This overload is much less efficient than <see cref = "SetProperty{T}(ref T,T,string)"/> and it
        /// should only be used when the former is not viable (eg. when the target property being
        /// updated does not directly expose a backing field that can be passed by reference).
        /// For performance reasons,it is recommended to use a stateful callback if possible through
        /// the <see cref = "SetProperty{TModel,T}(T,T,TModel,global::System.Action{TModel,T},string? )"/> whenever possible
        /// instead of this overload,as that will allow the C# compiler to cache the input callback and
        /// reduce the memory allocations. More info on that overload are available in the related XML
        /// docs. This overload is here for completeness and in cases where that is not applicable.
        /// </summary>
        /// <typeparam name = "T">The type of the property that changed.</typeparam>
        /// <param name = "oldValue">The current property value.</param>
        /// <param name = "newValue">The property's value after the change occurred.</param>
        /// <param name = "callback">A callback to invoke to update the property value.</param>
        /// <param name = "propertyName">(optional) The name of the property that changed.</param>
        /// <returns><see langword="true"/> if the property was changed,<see langword="false"/> otherwise.</returns>
        /// <remarks>
        /// The <see cref = "PropertyChanged"/> event is not raised if the current and new value for the target property are the same.
        /// </remarks>
        [global::System.CodeDom.Compiler.GeneratedCode("CommunityToolkit.Mvvm.SourceGenerators.INotifyPropertyChangedGenerator","8.2.0.0")]
        [global::System.Diagnostics.DebuggerNonUserCode]
        [global::System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
        protected bool SetProperty<T>(T oldValue,T newValue,global::System.Action<T> callback,[global::System.Runtime.CompilerServices.CallerMemberName] string? propertyName = null)
        {
            if (global::System.Collections.Generic.EqualityComparer<T>.Default.Equals(oldValue,newValue))
            {
                return false;
            }

            callback(newValue);
            OnPropertyChanged(propertyName);
            return true;
        }

        /// <summary>
        /// Compares the current and new values for a given property. If the value has changed,updates
        /// the property with the new value,then raises the <see cref = "PropertyChanged"/> event.
        /// See additional notes about this overload in <see cref = "SetProperty{T}(T,T,global::System.Action{T},string)"/>.
        /// </summary>
        /// <typeparam name = "T">The type of the property that changed.</typeparam>
        /// <param name = "oldValue">The current property value.</param>
        /// <param name = "newValue">The property's value after the change occurred.</param>
        /// <param name = "comparer">The <see cref = "global::System.Collections.Generic.IEqualityComparer{T}"/> instance to use to compare the input values.</param>
        /// <param name = "callback">A callback to invoke to update the property value.</param>
        /// <param name = "propertyName">(optional) The name of the property that changed.</param>
        /// <returns><see langword="true"/> if the property was changed,<see langword="false"/> otherwise.</returns>
        [global::System.CodeDom.Compiler.GeneratedCode("CommunityToolkit.Mvvm.SourceGenerators.INotifyPropertyChangedGenerator","8.2.0.0")]
        [global::System.Diagnostics.DebuggerNonUserCode]
        [global::System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
        protected bool SetProperty<T>(T oldValue,T newValue,global::System.Collections.Generic.IEqualityComparer<T> comparer,global::System.Action<T> callback,[global::System.Runtime.CompilerServices.CallerMemberName] string? propertyName = null)
        {
            if (comparer.Equals(oldValue,newValue))
            {
                return false;
            }

            callback(newValue);
            OnPropertyChanged(propertyName);
            return true;
        }

        /// <summary>
        /// Compares the current and new values for a given nested property. If the value has changed,
        /// updates the property and then raises the <see cref = "PropertyChanged"/> event.
        /// The behavior mirrors that of <see cref = "SetProperty{T}(ref T,T,string)"/>,
        /// with the difference being that this method is used to relay properties from a wrapped model in the
        /// current instance. This type is useful when creating wrapping,bindable objects that operate over
        /// models that lack support for notification (eg. for CRUD operations).
        /// Suppose we have this model (eg. for a database row in a table):
        /// <code>
        /// public class Person
        /// {
        ///     public string Name { get; set; }
        /// }
        /// </code>
        /// We can then use a property to wrap instances of this type into our observable model (which supports
        /// notifications),injecting the notification to the properties of that model,like so:
        /// <code>
        /// [INotifyPropertyChanged]
        /// public partial class BindablePerson
        /// {
        ///     public Model { get; }
        ///
        ///     public BindablePerson(Person model)
        ///     {
        ///         Model = model;
        ///     }
        ///
        ///     public string Name
        ///     {
        ///         get => Model.Name;
        ///         set => Set(Model.Name,value,Model,(model,name) => model.Name = name);
        ///     }
        /// }
        /// </code>
        /// This way we can then use the wrapping object in our application,and all those "proxy" properties will
        /// also raise notifications when changed. Note that this method is not meant to be a replacement for
        /// <see cref = "SetProperty{T}(ref T,T,string)"/>,and it should only be used when relaying properties to a model that
        /// doesn't support notifications,and only if you can't implement notifications to that model directly (eg. by having
        /// it implement <see cref = "global::System.ComponentModel.INotifyPropertyChanged"/>). The syntax relies on passing the target model and a stateless callback
        /// to allow the C# compiler to cache the function,which results in much better performance and no memory usage.
        /// </summary>
        /// <typeparam name = "TModel">The type of model whose property (or field) to set.</typeparam>
        /// <typeparam name = "T">The type of property (or field) to set.</typeparam>
        /// <param name = "oldValue">The current property value.</param>
        /// <param name = "newValue">The property's value after the change occurred.</param>
        /// <param name = "model">The model containing the property being updated.</param>
        /// <param name = "callback">The callback to invoke to set the target property value,if a change has occurred.</param>
        /// <param name = "propertyName">(optional) The name of the property that changed.</param>
        /// <returns><see langword="true"/> if the property was changed,<see langword="false"/> otherwise.</returns>
        /// <remarks>
        /// The <see cref = "PropertyChanged"/> event is not raised if the current and new value for the target property are the same.
        /// </remarks>
        [global::System.CodeDom.Compiler.GeneratedCode("CommunityToolkit.Mvvm.SourceGenerators.INotifyPropertyChangedGenerator","8.2.0.0")]
        [global::System.Diagnostics.DebuggerNonUserCode]
        [global::System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
        protected bool SetProperty<TModel,T>(T oldValue,T newValue,TModel model,global::System.Action<TModel,T> callback,[global::System.Runtime.CompilerServices.CallerMemberName] string? propertyName = null)
            where TModel : class
        {
            if (global::System.Collections.Generic.EqualityComparer<T>.Default.Equals(oldValue,newValue))
            {
                return false;
            }

            callback(model,newValue);
            OnPropertyChanged(propertyName);
            return true;
        }

        /// <summary>
        /// Compares the current and new values for a given nested property. If the value has changed,
        /// updates the property and then raises the <see cref = "PropertyChanged"/> event.
        /// The behavior mirrors that of <see cref = "SetProperty{T}(ref T,T,string)"/>,
        /// with the difference being that this method is used to relay properties from a wrapped model in the
        /// current instance. See additional notes about this overload in <see cref = "SetProperty{TModel,T}(T,T,TModel,global::System.Action{TModel,T},string)"/>.
        /// </summary>
        /// <typeparam name = "TModel">The type of model whose property (or field) to set.</typeparam>
        /// <typeparam name = "T">The type of property (or field) to set.</typeparam>
        /// <param name = "oldValue">The current property value.</param>
        /// <param name = "newValue">The property's value after the change occurred.</param>
        /// <param name = "comparer">The <see cref = "global::System.Collections.Generic.IEqualityComparer{T}"/> instance to use to compare the input values.</param>
        /// <param name = "model">The model containing the property being updated.</param>
        /// <param name = "callback">The callback to invoke to set the target property value,if a change has occurred.</param>
        /// <param name = "propertyName">(optional) The name of the property that changed.</param>
        /// <returns><see langword="true"/> if the property was changed,<see langword="false"/> otherwise.</returns>
        [global::System.CodeDom.Compiler.GeneratedCode("CommunityToolkit.Mvvm.SourceGenerators.INotifyPropertyChangedGenerator","8.2.0.0")]
        [global::System.Diagnostics.DebuggerNonUserCode]
        [global::System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
        protected bool SetProperty<TModel,T>(T oldValue,T newValue,global::System.Collections.Generic.IEqualityComparer<T> comparer,TModel model,global::System.Action<TModel,T> callback,[global::System.Runtime.CompilerServices.CallerMemberName] string? propertyName = null)
            where TModel : class
        {
            if (comparer.Equals(oldValue,newValue))
            {
                return false;
            }

            callback(model,newValue);
            OnPropertyChanged(propertyName);
            return true;
        }

        /// <summary>
        /// Compares the current and new values for a given field (which should be the backing field for a property).
        /// If the value has changed,updates the field and then raises the <see cref = "PropertyChanged"/> event.
        /// The behavior mirrors that of <see cref = "SetProperty{T}(ref T,T,string)"/>,with the difference being that
        /// this method will also monitor the new value of the property (a generic <see cref = "global::System.Threading.Tasks.Task"/>) and will also
        /// raise the <see cref = "PropertyChanged"/> again for the target property when it completes.
        /// This can be used to update bindings observing that <see cref = "global::System.Threading.Tasks.Task"/> or any of its properties.
        /// This method and its overload specifically rely on the <see cref = "TaskNotifier"/> type,which needs
        /// to be used in the backing field for the target <see cref = "global::System.Threading.Tasks.Task"/> property. The field doesn't need to be
        /// initialized,as this method will take care of doing that automatically. The <see cref = "TaskNotifier"/>
        /// type also includes an implicit operator,so it can be assigned to any <see cref = "global::System.Threading.Tasks.Task"/> instance directly.
        /// Here is a sample property declaration using this method:
        /// <code>
        /// private TaskNotifier myTask;
        ///
        /// public Task MyTask
        /// {
        ///     get => myTask;
        ///     private set => SetAndNotifyOnCompletion(ref myTask,value);
        /// }
        /// </code>
        /// </summary>
        /// <param name = "taskNotifier">The field notifier to modify.</param>
        /// <param name = "newValue">The property's value after the change occurred.</param>
        /// <param name = "propertyName">(optional) The name of the property that changed.</param>
        /// <returns><see langword="true"/> if the property was changed,<see langword="false"/> otherwise.</returns>
        /// <remarks>
        /// The <see cref = "PropertyChanged"/> event is not raised if the current and new value for the target property are
        /// the same. The return value being <see langword="true"/> only indicates that the new value being assigned to
        /// <paramref name = "taskNotifier"/> is different than the previous one,and it does not mean the new
        /// <see cref = "global::System.Threading.Tasks.Task"/> instance passed as argument is in any particular state.
        /// </remarks>
        [global::System.CodeDom.Compiler.GeneratedCode("CommunityToolkit.Mvvm.SourceGenerators.INotifyPropertyChangedGenerator","8.2.0.0")]
        [global::System.Diagnostics.DebuggerNonUserCode]
        [global::System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
        protected bool SetPropertyAndNotifyOnCompletion([global::System.Diagnostics.CodeAnalysis.NotNull] ref TaskNotifier? taskNotifier,global::System.Threading.Tasks.Task? newValue,[global::System.Runtime.CompilerServices.CallerMemberName] string? propertyName = null)
        {
            return SetPropertyAndNotifyOnCompletion(taskNotifier ??= new TaskNotifier(),newValue,null,propertyName);
        }

        /// <summary>
        /// Compares the current and new values for a given field (which should be the backing field for a property).
        /// If the value has changed,updates the field and then raises the <see cref = "PropertyChanged"/> event.
        /// This method is just like <see cref = "SetPropertyAndNotifyOnCompletion(ref TaskNotifier,global::System.Threading.Tasks.Task,string)"/>,
        /// with the difference being an extra <see cref = "global::System.Action{T}"/> parameter with a callback being invoked
        /// either immediately,if the new task has already completed or is <see langword="null"/>,or upon completion.
        /// </summary>
        /// <param name = "taskNotifier">The field notifier to modify.</param>
        /// <param name = "newValue">The property's value after the change occurred.</param>
        /// <param name = "callback">A callback to invoke to update the property value.</param>
        /// <param name = "propertyName">(optional) The name of the property that changed.</param>
        /// <returns><see langword="true"/> if the property was changed,<see langword="false"/> otherwise.</returns>
        /// <remarks>
        /// The <see cref = "PropertyChanged"/> event is not raised if the current and new value for the target property are the same.
        /// </remarks>
        [global::System.CodeDom.Compiler.GeneratedCode("CommunityToolkit.Mvvm.SourceGenerators.INotifyPropertyChangedGenerator","8.2.0.0")]
        [global::System.Diagnostics.DebuggerNonUserCode]
        [global::System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
        protected bool SetPropertyAndNotifyOnCompletion([global::System.Diagnostics.CodeAnalysis.NotNull] ref TaskNotifier? taskNotifier,global::System.Threading.Tasks.Task? newValue,global::System.Action<global::System.Threading.Tasks.Task?> callback,[global::System.Runtime.CompilerServices.CallerMemberName] string? propertyName = null)
        {
            return SetPropertyAndNotifyOnCompletion(taskNotifier ??= new TaskNotifier(),newValue,callback,propertyName);
        }

        /// <summary>
        /// Compares the current and new values for a given field (which should be the backing field for a property).
        /// If the value has changed,updates the field and then raises the <see cref = "PropertyChanged"/> event.
        /// The behavior mirrors that of <see cref = "SetProperty{T}(ref T,T,string)"/>,with the difference being that
        /// this method will also monitor the new value of the property (a generic <see cref = "global::System.Threading.Tasks.Task"/>) and will also
        /// raise the <see cref = "PropertyChanged"/> again for the target property when it completes.
        /// This can be used to update bindings observing that <see cref = "global::System.Threading.Tasks.Task"/> or any of its properties.
        /// This method and its overload specifically rely on the <see cref = "TaskNotifier{T}"/> type,which needs
        /// to be used in the backing field for the target <see cref = "global::System.Threading.Tasks.Task"/> property. The field doesn't need to be
        /// initialized,as this method will take care of doing that automatically. The <see cref = "TaskNotifier{T}"/>
        /// type also includes an implicit operator,so it can be assigned to any <see cref = "global::System.Threading.Tasks.Task"/> instance directly.
        /// Here is a sample property declaration using this method:
        /// <code>
        /// private TaskNotifier<int> myTask;
        ///
        /// public Task<int> MyTask
        /// {
        ///     get => myTask;
        ///     private set => SetAndNotifyOnCompletion(ref myTask,value);
        /// }
        /// </code>
        /// </summary>
        /// <typeparam name = "T">The type of result for the <see cref = "global::System.Threading.Tasks.Task{TResult}"/> to set and monitor.</typeparam>
        /// <param name = "taskNotifier">The field notifier to modify.</param>
        /// <param name = "newValue">The property's value after the change occurred.</param>
        /// <param name = "propertyName">(optional) The name of the property that changed.</param>
        /// <returns><see langword="true"/> if the property was changed,<see langword="false"/> otherwise.</returns>
        /// <remarks>
        /// The <see cref = "PropertyChanged"/> event is not raised if the current and new value for the target property are
        /// the same. The return value being <see langword="true"/> only indicates that the new value being assigned to
        /// <paramref name = "taskNotifier"/> is different than the previous one,and it does not mean the new
        /// <see cref = "global::System.Threading.Tasks.Task{TResult}"/> instance passed as argument is in any particular state.
        /// </remarks>
        [global::System.CodeDom.Compiler.GeneratedCode("CommunityToolkit.Mvvm.SourceGenerators.INotifyPropertyChangedGenerator","8.2.0.0")]
        [global::System.Diagnostics.DebuggerNonUserCode]
        [global::System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
        protected bool SetPropertyAndNotifyOnCompletion<T>([global::System.Diagnostics.CodeAnalysis.NotNull] ref TaskNotifier<T>? taskNotifier,global::System.Threading.Tasks.Task<T>? newValue,[global::System.Runtime.CompilerServices.CallerMemberName] string? propertyName = null)
        {
            return SetPropertyAndNotifyOnCompletion(taskNotifier ??= new TaskNotifier<T>(),newValue,null,propertyName);
        }

        /// <summary>
        /// Compares the current and new values for a given field (which should be the backing field for a property).
        /// If the value has changed,updates the field and then raises the <see cref = "PropertyChanged"/> event.
        /// This method is just like <see cref = "SetPropertyAndNotifyOnCompletion{T}(ref TaskNotifier{T},global::System.Threading.Tasks.Task{T},string)"/>,
        /// with the difference being an extra <see cref = "global::System.Action{T}"/> parameter with a callback being invoked
        /// either immediately,if the new task has already completed or is <see langword="null"/>,or upon completion.
        /// </summary>
        /// <typeparam name = "T">The type of result for the <see cref = "global::System.Threading.Tasks.Task{TResult}"/> to set and monitor.</typeparam>
        /// <param name = "taskNotifier">The field notifier to modify.</param>
        /// <param name = "newValue">The property's value after the change occurred.</param>
        /// <param name = "callback">A callback to invoke to update the property value.</param>
        /// <param name = "propertyName">(optional) The name of the property that changed.</param>
        /// <returns><see langword="true"/> if the property was changed,<see langword="false"/> otherwise.</returns>
        /// <remarks>
        /// The <see cref = "PropertyChanged"/> event is not raised if the current and new value for the target property are the same.
        /// </remarks>
        [global::System.CodeDom.Compiler.GeneratedCode("CommunityToolkit.Mvvm.SourceGenerators.INotifyPropertyChangedGenerator","8.2.0.0")]
        [global::System.Diagnostics.DebuggerNonUserCode]
        [global::System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
        protected bool SetPropertyAndNotifyOnCompletion<T>([global::System.Diagnostics.CodeAnalysis.NotNull] ref TaskNotifier<T>? taskNotifier,global::System.Threading.Tasks.Task<T>? newValue,global::System.Action<global::System.Threading.Tasks.Task<T>?> callback,[global::System.Runtime.CompilerServices.CallerMemberName] string? propertyName = null)
        {
            return SetPropertyAndNotifyOnCompletion(taskNotifier ??= new TaskNotifier<T>(),newValue,callback,propertyName);
        }

        /// <summary>
        /// Implements the notification logic for the related methods.
        /// </summary>
        /// <typeparam name = "TTask">The type of <see cref = "global::System.Threading.Tasks.Task"/> to set and monitor.</typeparam>
        /// <param name = "taskNotifier">The field notifier.</param>
        /// <param name = "newValue">The property's value after the change occurred.</param>
        /// <param name = "callback">(optional) A callback to invoke to update the property value.</param>
        /// <param name = "propertyName">(optional) The name of the property that changed.</param>
        /// <returns><see langword="true"/> if the property was changed,<see langword="false"/> otherwise.</returns>
        [global::System.CodeDom.Compiler.GeneratedCode("CommunityToolkit.Mvvm.SourceGenerators.INotifyPropertyChangedGenerator","8.2.0.0")]
        [global::System.Diagnostics.DebuggerNonUserCode]
        [global::System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
        private bool SetPropertyAndNotifyOnCompletion<TTask>(ITaskNotifier<TTask> taskNotifier,TTask? newValue,global::System.Action<TTask?>? callback,[global::System.Runtime.CompilerServices.CallerMemberName] string? propertyName = null)
            where TTask : global::System.Threading.Tasks.Task
        {
            if (ReferenceEquals(taskNotifier.Task,newValue))
            {
                return false;
            }

            bool isAlreadyCompletedOrNull = newValue?.IsCompleted ?? true;
            taskNotifier.Task = newValue;
            OnPropertyChanged(propertyName);
            if (isAlreadyCompletedOrNull)
            {
                if (callback != null)
                {
                    callback(newValue);
                }

                return true;
            }

            async void MonitorTask()
            {
                await global::CommunityToolkit.Mvvm.ComponentModel.__Internals.__TaskExtensions.GetAwaitableWithoutEndValidation(newValue!);
                if (ReferenceEquals(taskNotifier.Task,newValue))
                {
                    OnPropertyChanged(propertyName);
                }

                if (callback != null)
                {
                    callback(newValue);
                }
            }

            MonitorTask();
            return true;
        }

        /// <summary>
        /// An interface for task notifiers of a specified type.
        /// </summary>
        /// <typeparam name = "TTask">The type of value to store.</typeparam>
        [global::System.CodeDom.Compiler.GeneratedCode("CommunityToolkit.Mvvm.SourceGenerators.INotifyPropertyChangedGenerator","8.2.0.0")]
        private interface ITaskNotifier<TTask>
            where TTask : global::System.Threading.Tasks.Task
        {
            /// <summary>
            /// Gets or sets the wrapped <typeparamref name = "TTask"/> value.
            /// </summary>
            TTask? Task { get; set; }
        }

        /// <summary>
        /// A wrapping class that can hold a <see cref = "global::System.Threading.Tasks.Task"/> value.
        /// </summary>
        [global::System.CodeDom.Compiler.GeneratedCode("CommunityToolkit.Mvvm.SourceGenerators.INotifyPropertyChangedGenerator","8.2.0.0")]
        [global::System.Diagnostics.DebuggerNonUserCode]
        [global::System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
        protected sealed class TaskNotifier : ITaskNotifier<global::System.Threading.Tasks.Task>
        {
            /// <summary>
            /// Initializes a new instance of the <see cref = "TaskNotifier"/> class.
            /// </summary>
            internal TaskNotifier()
            {
            }

            private global::System.Threading.Tasks.Task? task;
            /// <inheritdoc/>
            global::System.Threading.Tasks.Task? ITaskNotifier<global::System.Threading.Tasks.Task>.Task { get => this.task; set => this.task = value; }

            /// <summary>
            /// Unwraps the <see cref = "global::System.Threading.Tasks.Task"/> value stored in the current instance.
            /// </summary>
            /// <param name = "notifier">The input <see cref = "TaskNotifier{TTask}"/> instance.</param>
            public static implicit operator global::System.Threading.Tasks.Task? (TaskNotifier? notifier)
            {
                return notifier?.task;
            }
        }

        /// <summary>
        /// A wrapping class that can hold a <see cref = "global::System.Threading.Tasks.Task{T}"/> value.
        /// </summary>
        /// <typeparam name = "T">The type of value for the wrapped <see cref = "global::System.Threading.Tasks.Task{T}"/> instance.</typeparam>
        [global::System.CodeDom.Compiler.GeneratedCode("CommunityToolkit.Mvvm.SourceGenerators.INotifyPropertyChangedGenerator","8.2.0.0")]
        [global::System.Diagnostics.DebuggerNonUserCode]
        [global::System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
        protected sealed class TaskNotifier<T> : ITaskNotifier<global::System.Threading.Tasks.Task<T>>
        {
            /// <summary>
            /// Initializes a new instance of the <see cref = "TaskNotifier{TTask}"/> class.
            /// </summary>
            internal TaskNotifier()
            {
            }

            private global::System.Threading.Tasks.Task<T>? task;
            /// <inheritdoc/>
            global::System.Threading.Tasks.Task<T>? ITaskNotifier<global::System.Threading.Tasks.Task<T>>.Task { get => this.task; set => this.task = value; }

            /// <summary>
            /// Unwraps the <see cref = "global::System.Threading.Tasks.Task{T}"/> value stored in the current instance.
            /// </summary>
            /// <param name = "notifier">The input <see cref = "TaskNotifier{TTask}"/> instance.</param>
            public static implicit operator global::System.Threading.Tasks.Task<T>? (TaskNotifier<T>? notifier)
            {
                return notifier?.task;
            }
        }
    }
}

// <auto-generated/>
#pragma warning disable
#nullable enable
namespace test
{
    /// <inheritdoc/>
    partial class MyViewModel
    {
        /// <inheritdoc cref="name"/>
        [global::System.CodeDom.Compiler.GeneratedCode("CommunityToolkit.Mvvm.SourceGenerators.ObservablePropertyGenerator","8.2.0.0")]
        [global::System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
        public string? Name
        {
            get => name;
            set
            {
                if (!global::System.Collections.Generic.EqualityComparer<string?>.Default.Equals(name,value))
                {
                    OnNameChanging(value);
                    OnNameChanging(default,value);
                    name = value;
                    OnNameChanged(value);
                    OnNameChanged(default,value);
                    OnPropertyChanged(global::CommunityToolkit.Mvvm.ComponentModel.__Internals.__KnownINotifyPropertyChangedArgs.Name);
                }
            }
        }

        /// <summary>Executes the logic for when <see cref="Name"/> is changing.</summary>
        /// <param name="value">The new property value being set.</param>
        /// <remarks>This method is invoked right before the value of <see cref="Name"/> is changed.</remarks>
        [global::System.CodeDom.Compiler.GeneratedCode("CommunityToolkit.Mvvm.SourceGenerators.ObservablePropertyGenerator","8.2.0.0")]
        partial void OnNameChanging(string? value);
        /// <summary>Executes the logic for when <see cref="Name"/> is changing.</summary>
        /// <param name="oldValue">The previous property value that is being replaced.</param>
        /// <param name="newValue">The new property value being set.</param>
        /// <remarks>This method is invoked right before the value of <see cref="Name"/> is changed.</remarks>
        [global::System.CodeDom.Compiler.GeneratedCode("CommunityToolkit.Mvvm.SourceGenerators.ObservablePropertyGenerator","8.2.0.0")]
        partial void OnNameChanging(string? oldValue,string? newValue);
        /// <summary>Executes the logic for when <see cref="Name"/> just changed.</summary>
        /// <param name="value">The new property value that was set.</param>
        /// <remarks>This method is invoked right after the value of <see cref="Name"/> is changed.</remarks>
        [global::System.CodeDom.Compiler.GeneratedCode("CommunityToolkit.Mvvm.SourceGenerators.ObservablePropertyGenerator","8.2.0.0")]
        partial void OnNameChanged(string? value);
        /// <summary>Executes the logic for when <see cref="Name"/> just changed.</summary>
        /// <param name="oldValue">The previous property value that was replaced.</param>
        /// <param name="newValue">The new property value that was set.</param>
        /// <remarks>This method is invoked right after the value of <see cref="Name"/> is changed.</remarks>
        [global::System.CodeDom.Compiler.GeneratedCode("CommunityToolkit.Mvvm.SourceGenerators.ObservablePropertyGenerator","8.2.0.0")]
        partial void OnNameChanged(string? oldValue,string? newValue);
    }
}

// <auto-generated/>
#pragma warning disable
#nullable enable
namespace CommunityToolkit.Mvvm.ComponentModel.__Internals
{
    /// <summary>
    /// A helper type providing cached,reusable <see cref="global::System.ComponentModel.PropertyChangedEventArgs"/> instances
    /// for all properties generated with <see cref="global::CommunityToolkit.Mvvm.ComponentModel.ObservablePropertyAttribute"/>.
    /// </summary>
    [global::System.CodeDom.Compiler.GeneratedCode("CommunityToolkit.Mvvm.SourceGenerators.ObservablePropertyGenerator","8.2.0.0")]
    [global::System.Diagnostics.DebuggerNonUserCode]
    [global::System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
    [global::System.ComponentModel.EditorBrowsable(global::System.ComponentModel.EditorBrowsableState.Never)]
    [global::System.Obsolete("This type is not intended to be used directly by user code")]
    internal static class __KnownINotifyPropertyChangedArgs
    {
        /// <summary>The cached <see cref="global::System.ComponentModel.PropertyChangedEventArgs"/> instance for all "Name" generated properties.</summary>
        [global::System.ComponentModel.EditorBrowsable(global::System.ComponentModel.EditorBrowsableState.Never)]
        [global::System.Obsolete("This field is not intended to be referenced directly by user code")]
        public static readonly global::System.ComponentModel.PropertyChangedEventArgs Name = new global::System.ComponentModel.PropertyChangedEventArgs("Name");
    }
}

// <auto-generated/>
#pragma warning disable
#nullable enable
namespace test
{
    /// <inheritdoc/>
    partial class MyViewModel
    {
        /// <summary>The backing field for <see cref="SayHelloCommand"/>.</summary>
        [global::System.CodeDom.Compiler.GeneratedCode("CommunityToolkit.Mvvm.SourceGenerators.RelayCommandGenerator","8.2.0.0")]
        private global::CommunityToolkit.Mvvm.Input.RelayCommand? sayHelloCommand;
        /// <summary>Gets an <see cref="global::CommunityToolkit.Mvvm.Input.IRelayCommand"/> instance wrapping <see cref="SayHello"/>.</summary>
        [global::System.CodeDom.Compiler.GeneratedCode("CommunityToolkit.Mvvm.SourceGenerators.RelayCommandGenerator","8.2.0.0")]
        [global::System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
        public global::CommunityToolkit.Mvvm.Input.IRelayCommand SayHelloCommand => sayHelloCommand ??= new global::CommunityToolkit.Mvvm.Input.RelayCommand(new global::System.Action(SayHello));
    }
}

Code and pdf at

https://ignatandrei.github.io/RSCG_Examples/v2/docs/CommunityToolkit.Mvvm