I have an API project created in C#. There's a desire to "simplify" something that it does which would mean creating a new API endpoint, which in the background would call several existing endpoints within the same API.
I'm concerned that this sort of recursion, an API calling itself, is bad practice and it'd be a better solution to have applications that make use of the API call the existing endpoints individually and manage the returned data within their own separate application logic. Am I right to be concerned?
Thanks
There is a whole lot of "it depends" in the answer.
If you moved logic out of your controllers and into shared libraries would it make sense for these two libraries to call one another directly, or would they be in the same library?
If they're in the same library and the data they access should all be in that same service, then I would call within the library.
All of our services take a ServiceCallContext object as a parameter. The service then creates a broker and tells the broker what connection string to use based on the ServiceCallContext.
In other words, some of our customers have their own databases so the service calls have to point the brokers to their databases.
I would like to take the code that looks at the ServiceCallContext and chooses the correct connection and put it in a base service class. My team lead doesn't like that idea because with services he feels that this would be 'hiding' behavior and that this would be a bad thing. He suggested that there may be better ways to accomplish the same thing through some sort of WCF extensions.
I honestly don't care how we implement the code so long as I can reuse it because I think it's absolutely silly for me to be rewriting it in every service I create. I began looking into some WCF videos on PluralSight and it looks like there's a lot of great stuff it can do but unfortunately I'm not quite sure where to start. Can anyone give me a little direction as to whether WCF can accomplish what I'm trying to do and if so what particular features of WCF am I looking for?
The functionality you need is a custom interceptor.
This allows you to tell the WCF stack to look at incoming messages and the do some action based on them. If you wrap the interceptor up into it's own assembly then you can reference it from multiple services.
I am new to MVC and Web API. I created two separate projects. One ASP.NET MVC 5 (MyUI) and other ASP.NET Web API 2 (MyApi). I would like to keep my API project separate from my UI layer.
The AccountController class in MVC project (MyUI) is essentially doing the same that the AccountController in the API project does (MyApi). I first thought about making the MyUI.AccountController a sub class of MyApi.AccountController but then I quickly realize that first inherits from Controller and second from ApiController type.
So my questions are:
In order to remove data access logic from MVC 5 project, should I
just convert the AccountController to a wrapper class which will
essentially call the corresponding methods from the
MyApi.AccountController?
Is there a better approach?
Edit:
Edit 2:
While trying to articulate the problem I realized that I was going about it incorrectly. My confusion came from the ASP.NET Identity implementations which were embedded within the API project. That needs to be moved to the Data Access layer and both controllers need to access them the same way which is a whole different can of worms :)
Thanks!!
Method 1 seems a plausible solution but what I would suggest is to create a new class library and there put your data logic. In that way, the MVC project and the Web Api project could connect to that class library.
The reason is that you never know if you write another UI layer, Service layer or other connectivity layer. All those layers could then connect to the same data logic layer.
Extract the common implementation into a separate project (a class library for instance). Your business logic must be the same no matter how you access it. After all, the web service and the site are only a view of the same information and the same control logic. In the future you might be required to write a fat client in WPF or a service in WCF and you do not want to rewrite everything, do you?
I think you are asking about layering application. basically the choice depends on requirements.If you are following data centric design check this layering
Research about DI,ORM,Repository Pattern, SOLID Principlese
We are building our first small implementation of ServiceStack and we need some clarification regarding DTO's located in a separate assembly that is shared between the client and the server.
The WIKI page for the new API recommends the following for DTO
In Service development your services DTOs provides your technology agnostic Service Layer which you want to keep clean and as 'dependency-free' as possible for maximum accessibility and potential re-use. Our recommendation is to keep your service DTOs in a separate largely dep-free assembly.
There is also this snippet
*But let's say you take the normal route of copying the DTOs (in either source of binary form) so you have something like this on the client:
[Route("/reqstars")]
public class AllReqstars : IReturn<List<Reqstar>> { }
The code on the client now just becomes:
var client = new JsonServiceClient(BaseUri);
List<Reqstar> response = client.Get(new AllReqstars());
Which makes a GET web request to the /reqstars route. When a custom route is not present on the client it automatically falls back to using ServiceStack's pre-defined routes.
My question is... does the "largely dep-free" assembly still require a dependency on ServiceStack due the the route attribute on the DTO classes?
The [Route] attribute exists in the ServiceStack.Interfaces project, so you still only need a reference to the dependency and impl-free ServiceStack.Interfaces.dll. This is by design, we want to ensure the minimum dependency as possible which is why we'll try to keep all metadata attributes you might use on DTO's in the Interfaces project.
The reason for wanting to keep your DTO's in a separate assembly is to reduce the dependencies required by your clients in order to use it. This makes it less invasive and more accessible for clients. Also your DTOs represent your Service Contract, keeping them separate encourages the good practice of decoupling them from the implementation, which you want to continue to be free to re-factor.
The objective is to build a service that I will then consume via jQuery and a standards based web front-end, mobile device "fat-clients," and very likely a WPF desktop application.
It seems like WCF would be a good option, but I've never built a RESTful service with WCF, so I'm not sure where to even begin on that approach.
The other option I'm thinking about is using ASP.NET MVC, adding some custom routes, add a few controller actions and using different views to push out JSON, xml, and other return types.
This project is mostly a learning exercise for myself, and I'd like to spend some extra time and do it "right" so I have a better undertanding of how the pieces fit together.
So my question is this, which approach should I use to build this RESTful service, and what are some advantages of doing it that way?
Normally, I would say WCF for any kind of hosted serice, but in the specific case for RESTful services using JSON as a serialization mechanism, I prefer ASP.NET MVC (which I will refer to as ASP.NET for the remainder of this answer).
One of the first reasons is because of the routing mechanism. In WCF, you have to define it on the contract, which is all well and good, but if you have to make quick changes to your routing, from my point of view, it's much easier to do them using the routing mechanism in ASP.NET.
Also, to the point above, if you have multiple services exposed over multiple interfaces in WCF, it's hard to get a complete image of your URL structure (which is important), whereas in ASP.NET you (typically) have all of the route assignments in one place.
The second thing about ASP.NET is that you are going to have access to all of the intrinsic objects that ASP.NET is known for (Request, Response, Server, etc, etc), which is essential when exposing an HTTP-specific endpoint (which is what you are creating). Granted, you can use many of these same things in WCF, but you have to specifically tell WCF that you are doing so, and then design your services with that in mind.
Finally, through personal experience, I've found that the DataContractJsonSerializer doesn't handle DateTimeOffset values too well, and it is the type that you should use over DateTime when working with a service (over any endpoint) which can be called by people over multiple timezones. In ASP.NET, there is a different serializer that you can use, or if you want, you can create your own ActionResult which uses a custom serializer for you. I personally prefer the JSON.Net serializer.
One of the nice things about the JSON.Net serializer and ASP.NET that I like is that you can use anonymous types with it, if you are smart. If you create a static generic method on a non-generic type which then delegates to an internal generic type, you can use type inference to easily utilize anonymous types for your serialized return values (assuming they are one-offs, of course, if you have a structure that is returned consistently, you should define it and use that).
It should also be mentioned that you don't have to completely discount WCF if developing a RESTful service. If you are pushing an ATOM or RSS feed out from your service then the classes in the System.ServiceModel.Syndication namespace of massive help in the construction and serialization of those feeds. Creating a simple subclass of the ActionResult class to take an instance of SyndicationFeed and then serialize it to the output stream when the ActionResult is executed is quite simple.
Here is a a thought that may help you make the decision between ASP.NET MVC and WCF. In the scenarios you describe, do you expect to need to use a protocol other than HTTP?
WCF is designed to be transport protocol agnostic and so it is very different than ASP.NET. It has channels and bindings, messages, service contracts, data contracts and behaviours. It provides very little in the way of guidance when it comes to building distributed applications. What it gives you is a clean slate to build on.
ASP.Net MVC is naturally a Http based framework. It deals with HTTP verbs, media types, URLs, response headers and request headers.
The question is which model is closer to what you are trying to build?
Now you mentioned ReST. If you really do want to build your distributed applications following the ReST constraints then you would be better to start with OpenRasta. It will guide you down that path.
You can do Rest in ASP.Net MVC and you can do it in WCF, but with those solutions, you will not fall into the pit of success ;-)
Personally, I am not crazy about implementing REST services in WCF. I find the asp.net mvc framework a more natural programming model for this.
The implementor of http://atomsite.net/ originally implemented the atompub specification in WCF and then rewrote the entire service using asp.net mvc. His experience echoed my comment above that for a pure REST service asp.net mvc is the way to go.
The only exception would be if I wanted to potentially expose a service in a restful and non restful way. Or if I was exposing an existing WCF service via REST.