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IoC/DI Containers

Dependency Injection is used widely in many large applications. DotVVM allows you to have your services injected in the viewmodel constructor or properties.

public class CustomersViewModel 
{
    // the parameters will be injected automatically by the DI container
    public CustomersViewModel(CustomerService customerService, ILogging log) 
    {
        ...        
    }

    // this service can be injected too if the container supports property injection
    [Bind(Direction.None)]
    public IAdditionalService AdditionalService { get; set; }
}

Basically, if you need any services in your viewmodel, you can request them in the constructor as parameters, or you can declare a public property in the viewmodel. In that case, don't forget to use the [Bind(Direction.None)] attribute to tell the serializer that it should not care about this property.

DotVVM uses the Microsoft.Extensions.DependencyInjection library to configure and resolve viewmodels and services.

Static Command Services

DotVVM 2.0 added the Static Command Services.

You can inject a service using the @service directive in the view and use it in binding expressions.

Dependency Injection in Controls

You can also use the dependency injection in custom controls - simply put the dependencies into contructor:

public class MyControl : HtmlGenericControl 
{
    private readonly IMyService service;

    public MyControl(IMyService service) 
    {
        this.service = service;
    }

    // ...
}

Note that you can use to inject your own services, but also services of the DotVVM framework.

  • ResourceManager - you can simply register a DotVVM resource for that request in control contructor
  • IDotvvmRequestContext - although in controls you get the request context in every lifecycle event, you can use constuctor injection in DotvvmBindableObjects that are not DotvvmControl, for example postback handlers or grid view columns.

All services injected using @service directive must be registered in the IServiceCollection.

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