https://github.com/jybbang/ReactiveUI-FluentValidation
It is a small library for ReactiveUI to support XAML Binding validation using *FluentValidation
https://github.com/jybbang/ReactiveUI-FluentValidation
fluentvalidation mvvm reactiveui validation
Last synced: 4 months ago
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It is a small library for ReactiveUI to support XAML Binding validation using *FluentValidation
- Host: GitHub
- URL: https://github.com/jybbang/ReactiveUI-FluentValidation
- Owner: jybbang
- License: mit
- Created: 2019-04-10T20:39:35.000Z (about 6 years ago)
- Default Branch: master
- Last Pushed: 2019-04-11T05:15:12.000Z (about 6 years ago)
- Last Synced: 2025-03-04T18:44:48.209Z (4 months ago)
- Topics: fluentvalidation, mvvm, reactiveui, validation
- Language: C#
- Homepage:
- Size: 41 KB
- Stars: 5
- Watchers: 2
- Forks: 2
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# ReactiveValidationObject
It is a small library for [ReactiveUI](https://reactiveui.net/) to support XAML Binding validation using [*FluentValidation](https://fluentvalidation.net/)
- ReactiveUI is one of the most powerful framworks for MVVM.
- It has a original validation library ([ReactiveUI.Validation](https://reactiveui.net/docs/handbook/user-input-validation/)), It is very simple to use and well functioned.
- But It does not support `INotifyDataErrorInfo` interface for XAML binding engine to display validation erros in your view.
- So, I wrap the base ViewModel (ReactiveObject) with a popular validation library [*FluentValidation](https://fluentvalidation.net/)
- To XAML binding, we should initialize the DataContext of View. Andthen we use some traditional XAML markup bindings (only some properties that we want to validate).
> CAUTION
>
> If you HATE to use XAML markup bindings. It's NOT for you.
## Get Started
### 1. Installation
ReactiveValidationObject can be installed using the Nuget package manager or the dotnet CLI:
Install-Package ReactiveUI-FluentValidation
Or you can just copy the `ReactiveValidationObject.cs` into your project.
After that you should get [*FluentValidation](https://fluentvalidation.net/) pakage.
### 2. Use case
I use a popular validation library *FluentValidation. Therefore you can learn more validation rules HERE - [https://fluentvalidation.net/](https://fluentvalidation.net/)
So this thime. I just show a how to use my library only.
This is our first ReactiveObject ViewModel class:
```csharp
using ReactiveUI;
public class AppViewModel : ReactiveObject
{
private string fullname;
private string surname;
private string forename;
public string Fullname
{
get => fullname;
set
{
this.RaiseAndSetIfChanged(ref fullname, value);
}
}
public string Surname
{
get => surname;
set
{
this.RaiseAndSetIfChanged(ref surname, value);
}
}
public string Forename
{
get => forename;
set
{
this.RaiseAndSetIfChanged(ref forename, value);
}
}
public ReactiveCommand SomeAction { get; }
public AppViewModel()
{
var isValid = this.WhenAnyValue(vm => vm.Surname, vm => vm.Forename)
.Select(x => !String.IsNullOrWhiteSpace(x.Item1)
&& !String.IsNullOrWhiteSpace(x.Item2));
SomeAction = ReactiveCommand.Create(() =>
{
Fullname = $"{Forename} {Surname}";
}, isValid);
}
}
```
As you can see it is work very well.
You can not click the button if suname and forename are empty:
However If you wanna display validation erros in your view.
Follow next step.
### 3. Create your validator
You would define a set of validation rules for our first class by inheriting from `AbstractValidator` :
```csharp
using FluentValidation;
public class AppViewModelValidator : AbstractValidator
{
public AppViewModelValidator()
{
RuleFor(vm => vm.Surname).NotEmpty();
RuleFor(vm => vm.Forename).NotEmpty();
}
}
```
### 4. Define your ReactiveValidationObject class
First of all we should change base class.
Before:
```csharp
public class AppViewModel : ReactiveObject
```
After:
```csharp
using ReactiveUI.FluentValidation;
public class AppViewModel : ReactiveValidationObject
```
And then you have to set an argument `AbstractValidator` to the base class constructor:
```csharp
public AppViewModel() : base(new AppViewModelValidator())
{
SomeAction = ReactiveCommand.Create(() =>
{
Fullname = $"{Forename} {Surname}";
}, isValid);
}
```
You now don't need define `IObservable isValid` any more. The validation result `isValid` will be set if validations are completed.
Finally, You should raise an event related property `this.RaiseValidation(nameof(Property))`:
```csharp
public string Surname
{
get => surname;
set
{
this.RaiseAndSetIfChanged(ref surname, value);
this.RaiseValidation(nameof(Surname));
}
}
public string Forename
{
get => forename;
set
{
this.RaiseAndSetIfChanged(ref forename, value);
this.RaiseValidation(nameof(Forename));
}
}
```
So, This is our first ReactiveValidationObject ViewModel class:
```csharp
using ReactiveUI;
using ReactiveUI.FluentValidation;
using FluentValidation;
public class AppViewModelValidator : AbstractValidator
{
public AppViewModelValidator()
{
RuleFor(vm => vm.Surname).NotEmpty();
RuleFor(vm => vm.Forename).NotEmpty();
}
}
public class AppViewModel : ReactiveValidationObject
{
private string fullname;
private string surname;
private string forename;
public string Fullname
{
get => fullname;
set
{
this.RaiseAndSetIfChanged(ref fullname, value);
}
}
public string Surname
{
get => surname;
set
{
this.RaiseAndSetIfChanged(ref surname, value);
this.RaiseValidation(nameof(Surname));
}
}
public string Forename
{
get => forename;
set
{
this.RaiseAndSetIfChanged(ref forename, value);
this.RaiseValidation(nameof(Forename));
}
}
public ReactiveCommand SomeAction { get; }
public AppViewModel() : base(new AppViewModelValidator())
{
SomeAction = ReactiveCommand.Create(() =>
{
Fullname = $"{Forename} {Surname}";
}, isValid);
}
}
```
### 5. Modify your View
As I mentioned our goal is to display errors in your view. To use XAML binding engine set DataContext:
```csharp
DataContext = ViewModel;
```
And then you should bind properties in xaml:
```xml
```
Now you can see errors in your view like this:
