vapor-docs/3.0/docs/getting-started/controllers.md

Controllers

Controllers are a great way to organize your code. They are collections of methods that accept a request and return a response.

A good place to put your controllers is in the Controllers folder.

Methods

Let's take a look at an example controller.

import Vapor

final class HelloController {
	func greet(_ req: Request) throws -> String {
		return "Hello!"
	}
}

Controller methods should always accept a Request and return something ResponseEncodable.

!!! note Futures whose expectations are ResponseEncodable (i.e, Future<String>) are also ResponseEncodable.

To use this controller, we can simply initialize it, then pass the method to a router.

let helloController = HelloController()
router.get("greet", use: helloController.greet)

Using Services

You will probably want to access your services from within your controllers. Just use the Request as a container to create services from within your route closures. Vapor will take care of caching the services.

final class HelloController {
	func greet(_ req: Request) throws -> String {
		return try req.make(BCryptHasher.self).hash("hello")
	}
}