CODEWITHSUNDEEP
c#asp.net-coredependency-injectionasp.net-core-mvcasp.net-core-2.1
O. Shai
O. Shai

Reputation: 813

Asp.net Core dependency injection in filters without [ServiceFilter] or [TypeFilter]

I need to inject some services with dependency injection to action filters. I'm familiar with the [ServiceFilter] and [TypeFilter] approach, but it's kind of ugly, messy, and unclear.

Is there a way I can set a filter in the normal way? without wrapping the filter I'm using with [ServiceFilter] or [TypeFilter]?

For example what I want:

[SomeFilterWithDI]
[AnotherFilterWithDI("some value")]
public IActionResult Index()
{
    return View("Index");
}

Instead of:

[ServiceFilter(typeof(SomeFilterWithDI))]
[TypeFilter(typeof(AnotherFilterWithDI), Arguments = new string[] { "some value" })]
public IActionResult Index()
{
    return View("Index");
}

It looks way different, this approach doesn't seem right to me.

Upvotes: 8

Views: 3038

Answers (1)

Edward
Edward

Reputation: 29966

For [SomeFilterWithDI], you could refer the comment from @Kirk larkin.

For [AnotherFilterWithDI("some value")], you could try passing Arguments from TypeFilterAttribute.

  • ParameterTypeFilter define the accept parameters. 

    public class ParameterTypeFilter: TypeFilterAttribute
{

    public ParameterTypeFilter(string para1, string para2):base(typeof(ParameterActionFilter))
    {
        Arguments = new object[] { para1, para2 };
    }
}

  • ParameterActionFilter accept the passed parameters. 

        public class ParameterActionFilter : IActionFilter
{
    private readonly ILogger _logger;
    private readonly string _para1;
    private readonly string _para2;

    public ParameterActionFilter(ILoggerFactory loggerFactory, string para1, string para2)
    {
        _logger = loggerFactory.CreateLogger<ParameterTypeFilter>();
        _para1 = para1;
        _para2 = para2;
    }

    public void OnActionExecuting(ActionExecutingContext context)
    {
        _logger.LogInformation($"Parameter One is {_para1}");
        // perform some business logic work

    }

    public void OnActionExecuted(ActionExecutedContext context)
    {
        // perform some business logic work
        _logger.LogInformation($"Parameter Two is {_para2}");
    }
}

    As the description from Arguments, ILoggerFactory loggerFactory is resolved by dependency injection container. para1 and para2 is resolved by ParameterTypeFilter. 

        //
// Summary:
//     Gets or sets the non-service arguments to pass to the Microsoft.AspNetCore.Mvc.TypeFilterAttribute.ImplementationType
//     constructor.
//
// Remarks:
//     Service arguments are found in the dependency injection container i.e. this filter
//     supports constructor injection in addition to passing the given Microsoft.AspNetCore.Mvc.TypeFilterAttribute.Arguments.
public object[] Arguments { get; set; }

  • Useage 

    [ParameterTypeFilter("T1","T2")]
public ActionResult Parameter()
{
    return Ok("Test");
}

Upvotes: 12

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