vapor-docs/2.0/docs/routing/controller.md

Basic Controller

Instead of defining all of your request handling logic as Closures in route files, you may wish to organize this behavior using Controller classes.

Controllers can group related request handling logic into a single class. They are normally stored in the Sources/App/Controllers directory.

Defining Controllers

import Vapor
import HTTP

final class HelloController {
    func sayHello(_ req: Request) throws -> ResponseRepresentable {
        return "Hello"
    }
}

You can define a route to this controller action like so:

let controller = HelloController()
drop.get("hello", handler: controller.sayHello)

Now, when a request matches the specified route URI, the Index method on the FirstController class will be executed. Of course, the route parameters will also be passed to the method.

Resource Controllers

Vapor resource routing assigns the typical "CRUD" routes to a controller with a single line of code.

drop.resource("users", UserController())

This single route declaration creates multiple routes to handle a variety of actions on the resource. The generated controller will already have methods stubbed for each of these actions, including notes informing you of the HTTP verbs and URIs they handle.

Verb	URI	Action
GET	test/index	test.index
POST	test/create	test.create
GET	test/show	test.show
PUT	test/replace	test.replace
PATCH	test/destroy	test.destroy
DELETE	test/destroy	test.destroy
DELETE	test/clear	test.clear

You can also custom method name, add makeResource method in the controller

final class UserController: ResourceRepresentable {
    func index(_ req: Request) throws -> ResponseRepresentable {
       ...
    }

    ...

    func makeResource() -> Resource<First> {
        return Resource(
            index: index,
            store: create,
            show: show,
            replace: replace,
            modify: update,
            destroy: delete,
            clear: clear
        )
    }
}