ReactiveProperty.XamariniOS 9.1.2

.NET 7.0
dotnet add package ReactiveProperty.XamariniOS --version 9.1.2
NuGet\Install-Package ReactiveProperty.XamariniOS -Version 9.1.2
This command is intended to be used within the Package Manager Console in Visual Studio, as it uses the NuGet module's version of Install-Package.
<PackageReference Include="ReactiveProperty.XamariniOS" Version="9.1.2" />
For projects that support PackageReference, copy this XML node into the project file to reference the package.
paket add ReactiveProperty.XamariniOS --version 9.1.2
#r "nuget: ReactiveProperty.XamariniOS, 9.1.2"
#r directive can be used in F# Interactive and Polyglot Notebooks. Copy this into the interactive tool or source code of the script to reference the package.
// Install ReactiveProperty.XamariniOS as a Cake Addin
#addin nuget:?package=ReactiveProperty.XamariniOS&version=9.1.2

// Install ReactiveProperty.XamariniOS as a Cake Tool
#tool nuget:?package=ReactiveProperty.XamariniOS&version=9.1.2

Japanese

ReactiveProperty

ReactiveProperty provides MVVM and asynchronous support features under Reactive Extensions. Target framework is .NET 6.0+, .NET Framework 4.7.2 and .NET Standard 2.0.

Build and Release

ReactiveProperty overview

ReactiveProperty is a very powerful and simple library.

Delay and Select

This sample app's ViewModel code is as below:

public class MainPageViewModel
{
    public ReactivePropertySlim<string> Input { get; }
    public ReadOnlyReactivePropertySlim<string> Output { get; }
    public MainPageViewModel()
    {
        Input = new ReactivePropertySlim<string>("");
        Output = Input
            .Delay(TimeSpan.FromSeconds(1))
            .Select(x => x.ToUpper())
            .ObserveOnDispatcher()
            .ToReadOnlyReactivePropertySlim();
    }
}

It is really simple and understandable (I think!). Because there are NOT any base classes and interfaces. Just has declarative code between Input property and Output property.

All steps are written in the "Getting Started" section in the ReactiveProperty documentation.

The concept of ReactiveProperty is simple that is a core class what name is ReactiveProperty[Slim], it is just a wrap class what has a value, and implements IObservable<T> and INotifyPropertyChanged, IObservable<T> is for connect change event of the property value to Rx LINQ method chane, INotifyPropertyChanged is for data binding system such as WPF, WinUI and MAUI.

And an important concept of ReactiveProperty is "Fun programing". ViewModel code with ReactiveProperty is very simple.

ViewModel's popular implementation:

public class AViewModel : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;

    private string _name;
    public string Name
    {
        get => _name;
        set
        {
            _name = value;
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(Name)));

            // Update a command status
            DoSomethingCommand.RaiseCanExecuteChanged();
        }
    }

    private string _memo;
    public string Memo
    {
        get => _memo;
        set
        {
            _memo = value;
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(Memo)));

            // Update a command status
            DoSomethingCommand.RaiseCanExecuteChanged();
        }
    }

    // DelegateCommand is plane ICommand implementation.
    public DelegateCommand DoSomethingCommand { get; }

    public AViewModel()
    {
        DoSomethingCommand = new DelegateCommand(
            () => { ... },
            () => !string.IsNullOrEmpty(Name) && !string.IsNullOrEmpty(Memo)
        );
    }
}

Binding code:

<TextBlock Text="{Binding Name}">
<TextBlock Text="{Binding Memo}">

ViewModel's implementation using ReactiveProperty:

public class AViewModel
{
    public ReactivePropertySlim<string> Name { get; }
    public ReactivePropertySlim<string> Memo { get; }
    public ReactiveCommandSlim DoSomethingCommand { get; }

    public AViewModel()
    {
        Name = new ReactiveProperty<string>()
            .SetValidateNotifyError(x => string.IsNullOrEmpty(x) ? "Invalid value" : null);
        Memo = new ReactiveProperty<string>()
            .SetValidateNotifyError(x => string.IsNullOrEmpty(x) ? "Invalid value" : null);
        DoSomethingCommand = new[]
            {
                Name.ObserveHasErrors,
                Memo.ObserveHasErrors,
            }
            .CombineLatestValuesAreAllFalse()
            .ToReactiveCommand()
            .WithSubscribe(() => { ... });
    }
}

Binding code:

<TextBlock Text="{Binding Name.Value}">
<TextBlock Text="{Binding Memo.Value}">

It's very simple.

ReactiveProperty doesn't provide base class by ViewModel, which means that ReactiveProperty can be used together with another MVVM libraries such as Prism, Microsoft.Toolkit.Mvvm and etc.

Documentation

ReactiveProperty documentation

NuGet packages

Package Id Version and downloads Description
ReactiveProperty The package includes all core features.
ReactiveProperty.Core The package includes minimum classes such as ReactivePropertySlim<T> and ReadOnlyReactivePropertySlim<T>. And this doesn't have any dependency even System.Reactive. If you don't need Rx features, then it fits.
ReactiveProperty.WPF The package includes EventToReactiveProperty and EventToReactiveCommand for WPF. This is for .NET 6 or later and .NET Framework 4.7.2 or later.
ReactiveProperty.Blazor The package includes validation support for EditForm component of Blazor with ReactiveProperty validation feature. This is for .NET 6.0 or later.

Following packages are maitanance phase.

Package Id Version and downloads Description
ReactiveProperty.UWP The package includes EventToReactiveProperty and EventToReactiveCommand for UWP.
ReactiveProperty.XamarinAndroid The package includes many extension methods to create IObservable from events for Xamarin.Android native.
ReactiveProperty.XamariniOS The package includes many extension methods to bind ReactiveProperty and ReactiveCommand to Xamarin.iOS native controls.

Support

I'm not watching StackOverflow and other forums to support ReactiveProperty, so please feel free to post questions at Github issues. I'm available Japanese(1st language) and English(2nd language).

If too many questions are posted, then I plan to separate posting place about feature requests, issues, questions.

Author info

Yoshifumi Kawai a.k.a. @neuecc is Founder/CEO/CTO of Cysharp, Inc in Tokyo, Japan. Awarded Microsoft MVP for Developer Technologies since April, 2011. He is an original owner of ReactiveProperty.

Takaaki Suzuki a.k.a. @xin9le software developer in Fukui, Japan. Awarded Microsoft MVP for Developer Technologies since July, 2012.

Kazuki Ota a.k.a. @okazuki software developer in Tokyo, Japan. Awarded Microsoft MVP for Windows Development since July 2011 to Feb 2017. Now, working at Microsoft Japan.

Product Versions
.NET net7.0-ios16.1
Compatible target framework(s)
Additional computed target framework(s)
Learn more about Target Frameworks and .NET Standard.

NuGet packages

This package is not used by any NuGet packages.

GitHub repositories

This package is not used by any popular GitHub repositories.

Version Downloads Last updated
9.1.2 59 3/12/2023
9.0.0 107 2/12/2023
9.0.0-pre202302040959 45 2/4/2023
9.0.0-pre202301080724 54 1/8/2023
9.0.0-pre202301050852 56 1/5/2023
8.2.0 212 11/10/2022
8.1.2 321 6/6/2022
8.1.2-pre202206051057 75 6/5/2022
8.1.1 300 5/27/2022
8.1.0 316 4/30/2022
8.1.0-pre202204290912 86 4/29/2022
8.1.0-pre202204290644 78 4/29/2022
8.0.5 292 3/24/2022
8.0.5-pre202203191529 76 3/19/2022
8.0.5-pre202203191312 74 3/19/2022
8.0.4 302 3/5/2022
8.0.4-pre202203040658 79 3/4/2022
8.0.3 233 12/5/2021
8.0.3-pre202112031043 773 12/3/2021
8.0.3-pre202112030833 733 12/3/2021
8.0.2 788 11/21/2021
8.0.1 403 11/20/2021
8.0.1-pre202111200140 479 11/20/2021
8.0.0 236 11/9/2021
8.0.0-pre202111090825 140 11/9/2021
8.0.0-pre202110240626 158 10/24/2021
8.0.0-pre202110161410 222 10/16/2021
8.0.0-pre202110160852 137 10/16/2021
8.0.0-pre202110160831 155 10/16/2021
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8.0.0-pre202110071401 165 10/7/2021
8.0.0-pre202110060758 179 10/6/2021
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8.0.0-pre202109190434 215 9/19/2021
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7.8.0-pre202102201703 170 2/20/2021
7.7.1 284 2/19/2021
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7.6.1 280 1/15/2021
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7.5.1 396 10/19/2020
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