CODEWITHSUNDEEP
c#dependency-injectionunity-containerclass-libraryactionfilterattribute
ScubaSteve
ScubaSteve

Reputation: 8270

How can get access to Unity container in a class library ActionFilterAttribute?

So, I have a web project that utilizes Unity to inject UserRepository for interfaces IUserRepository. I have a class library which contains a custom ActionFilterAttribute. This custom attribute class is used on many actions already. I want to add some code to it to check for a value in the database based on a user. To do this, I need access to the UserRepository. I could do it the old fashioned way with using statements and directly access UserRepository, but I would like to utilize the DI and resolve IUserRepository. How can I get access to what the web is resolving IUserRepository to, inside the custom attribute class since ActionFilterAttribute needs an empty constructor?

Upvotes: 0

Views: 919

Answers (3)

Victor Wilson
Victor Wilson

Reputation: 1846

This is an old question, but I found you can access your dependency resolution in an ActionFilterAttribute by using the actionContext parameter like so:

MyFooService myFooService = actionContext.Request.GetDependencyScope().GetService(typeof(MyFooService)) as MyFooService;

Upvotes: 0

ScubaSteve
ScubaSteve

Reputation: 8270

So, although I decided to not do the user check inside the custom attribute, the solution to allow for the injection inside the custom attribute can be used elsewhere. I had a property in the attribute:

public IUserRepository UserRepository { get; set; }

In the web's Global.asax.cs, I injected it via a property injection:

container.RegisterType<NameOfCustomAttribute>(new InjectionProperty("UserRepository", 
                                        new UserRepository(ConfigurationManager.ConnectionStrings["DBName"].ConnectionString)));

Upvotes: 0

James Lucas
James Lucas

Reputation: 2522

Attributes are metadata objects. They shouldn't be involved in database access. Use a separate service to read the attribute values and as a result access the database.

Upvotes: 1

Related Questions