CODEWITHSUNDEEP
c#servicestack
Simon
Simon

Reputation: 6152

Accessing ServiceStack requestDto object by type

I'm using a ServiceStack request filter that I want to inspect one of the properties of the requestDTO parameter. This parameter is strongly typed at runtime but at compile time is a generic object.

The filter will be used on multiple service calls and therefore the requestDTO type will change depending on which has been called. Therefore I cannot perform a specific cast on it. BUT, regardless of type, the requestDTO object will always have a string property named 'AppID'. It is this property I wish to access.

Here's my code (doesn't currently compile):

 public override void Execute(ServiceStack.ServiceHost.IHttpRequest req, ServiceStack.ServiceHost.IHttpResponse res, object requestDto)
        {
            //Check only for non-local requests
            if (!req.IsLocal)
            {                
                var app = this._appIDs.Apps.Where(x => x.ID == requestDto.AppID).FirstOrDefault();

                var errResponse = DtoUtils.CreateErrorResponse("401", "Unauthorised", null);
                var contentType = req.ResponseContentType;
                res.WriteToResponse(req, errResponse);
                res.EndRequest(); //stops further execution of this request
                return;
            }
        }

This line doesn't compile:

 var app = this._appIDs.Apps.Where(x => x.ID == requestDto.AppID).FirstOrDefault();

Do I need to be dealing with reflection here to access my object or is there some way built in to ServiceStack itself?

Upvotes: 3

Views: 139

Answers (1)

mythz
mythz

Reputation: 143399

The preferred approach when applying generic functionality to common Request DTO's is to have them implement the same interface, e.g:

public interface IHasAppId
{
    public string AppId { get; set; }
}

public class RequestDto1 : IHasAppId { ... }
public class RequestDto2 : IHasAppId { ... }

Then in your filter you can just do:

var hasAppId = requestDto as IHasAppId;
if (hasAppId != null)
{
    //do something with hasAppId.AppId
    ...
}

You can also avoid the use of an interface and use reflection instead, but that will be slower and less readable, so I recommend interfaces instead.

Upvotes: 5

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