Making Nancy Modules easier to manage

posted on 03 Nov 2013 | NancyFX

One problem I think a lot of developers have, is creating Controllers and Modules that are small and maintainable. Sometimes when you add some querying, bit of validation, pass it off to a repository or service, etc. It begins to become a little bit too big.

Lets assume our we have an AccountModule it Gets a Login route to load the UI, and Posts to a Login route to authenticate the user, and do something.

It also Gets a Register route to load the UI, and Posts to a Register route to register the new user.

Without an actual implementation, something like this:

public class AccountModule : NancyModule
    public AccountModule() : base("/account")
        Get["/login"] = _ => "login";
        Post["/login"] = _ => "login";

        Get["/register"] = _ => "register";
        Post["/register"] = _ => "register";

To begin with, we only have 4 things to implement, its rather small, somewhat easy to manage, but what happens when we want to update an account?

Get["details"] = _ => "details...";
Post["details"] = _ => "details...";

Then we want to have a profile...

Get["profile"] = _ => "profile...";

It just keeps adding up...

At this point it begins to get cluttered. Not only that, I believe this also breaks the Single Responsibility Principal.

My solution!

This isn't anything new, I personally haven't seen anyone blog about this stuff but I have absolutely no doubt people most likely create controllers like this in MVC

So that's why I've decided Modules should be broken up into Functionality rather than Functional Areas.

All these things hang off Account, so lets create an Account folder in our Modules folder.

Inside this folder we can create 4 new modules.

So we have 4 modules rather than 1:

  1. DetailsModule
  2. LoginModule
  3. ProfileModule
  4. RegisterModule

As you can expect, these are all really small now:

public class DetailsModule : NancyModule
    public DetailsModule()
        : base("/account/details")
        Get["/"] = _ => "details";

public class LoginModule : NancyModule
    public LoginModule()
        : base("/account/login")
        Get["/"] = _ => "login";
        Post["/"] = _ => "login";

public class ProfileModule : NancyModule
    public ProfileModule()
        : base("/account/profile")
        Get["/"] = _ => "profile...";

public class RegisterModule : NancyModule
    public RegisterModule()
        : base("/account/register")
        Get["/"] = _ => "register";
        Post["/"] = _ => "register";

From our folder perspective we can easily find all Modules under the /account route, and easily find the one related to Login, or Register, etc.

This also makes unit testing easier since we only need to worry about dependencies related to a specific piece of functionality.

Login might use a RavenDB session and Password Hashing Service, while Profile may use RavenDB and a 3rd party Image hosting service for Profile pictures.

Disagree or have a better way? Would love to hear! Share in the comments :)

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