TypeSafeMiddleware

public protocol TypeSafeMiddleware

The protocol that type-safe middleware must implement to be used in Kitura Codable routes.

Classes or structs conforming to TypeSafeMiddleware must contain a static handle function that processes an incoming request. On success, the handle function creates an instance of Self and passes this instance to the users route handler.

Usage Example:

In this example, a UserMiddleware struct is defined that checks the request for the header “TestHeader”. If the header is found UserMiddleware initialises itself with the header and passes itself to the route. If the header is not found it returns a RequestError.

struct UserMiddleware: TypeSafeMiddleware {
    let header: String

    static func handle(
                request: RouterRequest,
                response: RouterResponse,
                completion: @escaping (UserMiddleware?, RequestError?) -> Void
    ) {
        guard let expectedHeader = request.headers["TestHeader"] else {
            return completion(nil, .badRequest)
        }
        let selfInstance: UserMiddleware = UserMiddleware(header: expectedHeader)
        completion(selfInstance, nil)
    }
}