Is ReactiveUI Production Ready?

Question

I've been looking into the feasability of using Reactive UI in production code. Some of the features are really appealing, but I have concerns about taking a dependency on this library. These include:

1. Whacky naming and conventions. For example, protected members starting with lower case, and the RaiseAndSetIfChanged method depends on your private member beginning with an underscore. I understand Paul Betts (ReactiveUI author) has a Ruby background, so I guess that's where the odd naming stems from. However, this will cause a real issue for me, since standard naming (as per Stylecop) is enforced throughout my project. Even if it wasn't enforced, I'd be concerned by the resultant inconsistency in naming that this will cause.

2. Lack of documentation/samples. There is some documentation and a lonely sample. However, the documentation is just a series of (old) blog posts and the sample is based on V2 of the library (it's now on V4).

3. Odd design, in parts. For example, logging is abstracted so as not to take a dependency on a specific logging framework. Fair enough. However, since I use log4net (and not NLog) I will need my own adapter. I think that will require me to implement IRxUIFullLogger, which has a metric crapload of methods in it (well over 50). I would have thought a far better approach would be to define a very simple interface and then provide extension methods within ReactiveUI to facilitate all the requisite overloads. In addition, there's this weird IWantsToRegisterStuff interface that the NLog assembly depends on, that I won't be able to depend on (because it's an internal interface). I'm hoping I don't need that...

   Anyway, my concern here is the overall design of the library. Has anyone been bitten by this?

4. I'm already using MVVM Light extensively. I know Paul did a blog post where he explains you can technically use both, but my concern is more around maintainability. I suspect it would be horribly confusing having both intermingled in one's code base.

Does anyone have hands-on experience with using Reactive UI in production? If so, are you able to allay or address any of my above concerns?

Answer 1

Let's go through your concerns piece by piece:

#1. "Whacky naming and conventions."

Now that ReactiveUI 4.1+ has CallerMemberName, you don't have to use the conventions at all (and even then, you can override them via RxApp.GetFieldNameForPropertyFunc). Just write a property as:

int iCanNameThisWhateverIWant;
public int SomeProperty {
    get { return iCanNameThisWhateverIWant; }
    set { this.RaiseAndSetIfChanged(ref iCanNameThisWhateverIWant, value); }
}

#2. Lack of documentation/samples

This is legit, but here's some more docs / samples:

• http://docs.reactiveui.net/ (this is the official ReactiveUI documentation, a work in progress but definitely where you want to start)
• https://github.com/reactiveui/ReactiveUI.Samples
• https://github.com/reactiveui/RxUI_QCon
• https://github.com/play/play-windows

#3. "I would have thought a far better approach would be to define a very simple interface and then provide extension methods within ReactiveUI to facilitate all the requisite overloads"

Implement IRxUILogger instead, it has a scant two methods :) ReactiveUI will fill in the rest. IRxUIFullLogger is only there if you need it.

"In addition, there's this weird IWantsToRegisterStuff interface "

You don't need to know about this :) This is only for dealing with ReactiveUI initializing itself so that you don't have to have boilerplate code.

4. "I suspect it would be horribly confusing having both intermingled in one's code base."

Not really. Just think of it as "MVVM Light with SuperPowers".

Answer 2

I am answering as someone who has used ReactiveUI in a few production systems, has had issues with the way RxUI does stuff, and has submitted patches to try and fix issues I've had.

Disclaimer: I don't use all the features of RxUI. The reason being I don't agree with the way those features have been implemented. I'll detail my changes as I go.

1. Naming. I thought this was odd too. This ended up being one of the features I don't really use. I use PropertyChanged.Fody to weave in the change notification using AOP. As a result my properties look like auto properties.

2. Doco. Yes there could be more. Especially with the newer parts like routing. This possibly is a reason why I don't use all of RxUI.

3. Logging. I've had issues with this in the past. See pull request 69. At the end of the day I see RxUI as a very opinionated framework. If you don't agree with that opinion you can suggest changes, but that's all. Opinionated does not make it bad.

4. I use RxUI with Caliburn Micro. CM handles View-ViewModel location and binding, Screen and Conductors. I don't use CM's convention binding. RxUI handles Commands, and ViewModel INPC code, and allows me to react to property changes using Reactive instead of the traditional approaches. By keeping these things separate I find it much easier to mix the two together.

Does any of these issues have anything to do with being production ready? Nope. ReactiveUI is stable, has a decently sized user base, problems get solved quickly in the google group and Paul is receptive to discussion.

Answer 3

I use it in production and so far RxUI has been perfectly stable. The application has had problems with stability, some to do with EMS, others with an UnhandledException handler that was causing more problems than it was solving, but I've not had any problems with the ReactiveUI part of the application. However, I have had issues regarding the ObservableForProperty not firing at all, which I may have used incorrectly and did work consistently (incorrectly) in my test code as well as in the UI at run time.

-1. Paul explains that the _Upper is due to using reflection to get at the private field in your class. You can either use a block such as below to deal with the StyleCop and Resharper messages, which is easy to generate (from the Resharper SmartTag)

    /// <summary>The xxx view model.</summary>
    public class XXXViewModel : ReactiveObject
    {
    #pragma warning disable 0649
    // ReSharper disable InconsistentNaming

    [SuppressMessage("StyleCop.CSharp.NamingRules", 
      "SA1306:FieldNamesMustBeginWithLowerCaseLetter",
      Justification = "Reviewed. ReactiveUI field.")]
    private readonly bool _IsRunning;

    [SuppressMessage("StyleCop.CSharp.NamingRules", 
      "SA1306:FieldNamesMustBeginWithLowerCaseLetter",
      Justification = "Reviewed. ReactiveUI field.")]
    private string _Name;
    ....

or change your properties from the full

    /// <summary>Gets or sets a value indicating whether is selected.</summary>
    public bool IsSelected
    {
        get { return _IsSelected; }
        set { this.RaiseAndSetIfChanged(x => x.IsSelected, value); }
    }

to its component parts such as

    /// <summary>Gets or sets a value indicating whether is selected.</summary>
    public bool IsSelected
    {
        get { return _isSelected; }
        set 
        { 
            if (_isSelected != value)
            {
                this.RaisePropertyChanging(x => x.IsSelected); 
                _isSelected = value;
                this.RaisPropertyChanged(x=>x.IsSelected);
            }
        }
    }

This pattern is also useful where you don't actually supply a "simple" property accessor, but may require a more derived variant where setting one value affects multiple others.

-2. Yes the documentation isn't ideal but I found that after Rx, picking up the RxUI samples was quite easy. I also note that the jumps from 2->4 seem to have all come with the changes to support Windows 8/Windows 8 Phone, and having picked up ReactiveUI for a Windows Store App then the DotNet 4.5 support is excellent. i.e. use of [CallerName] now means that you simply this.RaiseAndSetIFChanged(value) no need for the expression.

-3. I haven't any feedback on the logging side as I've not elected to use it.

-4. I've not mixed and matched with others frameworks either.

There's also a list of other contributors to ReactiveUI 4.2 at http://blog.paulbetts.org/index.php/2012/12/16/reactiveui-4-2-is-released/, including Phil Haack.