Hummingbird routing and requests – The.Swift.Dev.


Routing on the server aspect means the server goes to ship a response based mostly on the URL path that the shopper referred to as when firing up the HTTP request. After all the server can examine further parameters and headers to construct the ultimate response, however once we speak about routing generally, we normally check with the trail parts. Hummingbird makes use of a trie-based router, which is a quick and environment friendly manner of trying up routes. It is fairly easy to reply to HTTP request utilizing the built-in router, you’ll be able to merely add your fundamental route handlers like this:

 
router.on("foo", technique: .HEAD) { _ -> HTTPResponseStatus in .okay }
router.on("foo", technique: .GET) { _ -> HTTPResponseStatus in .okay }
router.on("foo", technique: .POST) { _ -> HTTPResponseStatus in .okay }
router.on("foo", technique: .PUT) { _ -> HTTPResponseStatus in .okay }
router.on("foo", technique: .PATCH) { _ -> HTTPResponseStatus in .okay }
router.on("foo", technique: .DELETE) { _ -> HTTPResponseStatus in .okay }


router.head("foo") { _ -> HTTPResponseStatus in .okay }
router.get("foo") { _ -> HTTPResponseStatus in .okay }
router.put("foo") { _ -> HTTPResponseStatus in .okay }
router.put up("foo") { _ -> HTTPResponseStatus in .okay }
router.patch("foo") { _ -> HTTPResponseStatus in .okay }
router.delete("foo") { _ -> HTTPResponseStatus in .okay }

In Hummingbird it’s also potential to register use a operate as a substitute of a block. Handler features will be async and throwing too, so you’ll be able to mark the blocks with these key phrases or use asynchronous Swift features when registering route handlers. Should you do not present the primary parameter, the trail as a string, the route handler goes to be connected to the bottom group. 👍

You can too prefix a path element with a colon, this may flip that element right into a dynamic route parameter. The parameter goes to be named after the trail element, by merely dropping the colon prefix. You may entry parameters inside your route handler by means of the req.parameters property. Additionally it is potential to register a number of parts utilizing a / character.

public extension HBApplication {
    
    func configure() throws {

        router.get { _ async throws in "Hiya, world!" }

        router.get("whats up/:title") { req throws in
            guard let title = req.parameters.get("title") else {
                throw HBHTTPError(
                    .badRequest,
                    message: "Invalid title parameter."
                )
            }
            return "Hiya, (title)!"
        }

        let group = router.group("todos")
        group.get(use: checklist)
        group.put up(use: create)
        
        let idGroup = group.group(":todoId")
        idGroup.head(use: examine)
        idGroup.get(use: fetch)
        idGroup.put(use: replace)
        idGroup.patch(use: patch)
        idGroup.delete(use: delete)

        
        router.group("todos")
            .get(use: checklist)
            .put up(use: create)
            .group(":todoId")
                .head(use: examine)
                .get(use: fetch)
                .put(use: replace)
                .patch(use: patch)
                .delete(use: delete)

    }

    func checklist(_ req: HBRequest) async throws -> HTTPResponseStatus { .okay }
    func examine(_ req: HBRequest) async throws -> HTTPResponseStatus { .okay }
    func fetch(_ req: HBRequest) async throws -> HTTPResponseStatus { .okay }
    func create(_ req: HBRequest) async throws -> HTTPResponseStatus { .okay }
    func replace(_ req: HBRequest) async throws -> HTTPResponseStatus { .okay }
    func patch(_ req: HBRequest) async throws -> HTTPResponseStatus { .okay }
    func delete(_ req: HBRequest) async throws -> HTTPResponseStatus { .okay }
}

It’s potential to make use of a wildcard character () when detecting path parts and the recursive model (*) to catch all the things. Additionally you should use the ${title} syntax to catch a named request parameter even with a prefix or suffix, however you’ll be able to’t insert this in the midst of a path element. (e.g. “prefix-${title}.jpg” will not work, however “${title}.jpg” is simply high quality) 💡

import Hummingbird
import HummingbirdFoundation

extension HBApplication {

    func configure(_ args: AppArguments) throws {

        router.get("foo-${title}", use: catchPrefix)
        router.get("${title}.jpg", use: catchSuffix)
        
        router.get("*", use: catchOne)
        router.get("*/*", use: catchTwo)

        router.get("**", use: catchAll)
        
    }
    
    
    func catchOne(_ req: HBRequest) async throws -> String {
        "one"
    }

    
    func catchTwo(_ req: HBRequest) async throws -> String {
        "two"
    }
    
    
    func catchAll(_ req: HBRequest) async throws -> String {
        "all: " + req.parameters.getCatchAll().joined(separator: ", ")
    }
    
    
    func catchPrefix(_ req: HBRequest) async throws -> String {
        "prefix: " + (req.parameters.get("title") ?? "n/a")
    }
    
    
    func catchSuffix(_ req: HBRequest) async throws -> String {
        "suffix: " + (req.parameters.get("title") ?? "n/a")
    }
}

Additionally it is potential to edit the auto-generated response for those who specify the .editResponse possibility.

router.get("foo", choices: .editResponse) { req -> String in
    req.response.standing = .okay
    req.response.headers.replaceOrAdd(
        title: "Content material-Sort", 
        worth: "software/json"
    )
    return #"{"foo": "bar"}"#
}

Hummingbird help for physique streaming is wonderful, you’ll be able to stream a HTTP request physique by utilizing the .streamBody possibility. The physique stream has a sequence property, which you should use to iterate by means of the incoming ByteBuffer chunks when dealing with the request. 🔄

func configure() throws { 
    router.put up("foo", choices: .streamBody) { req async throws -> String in
        guard
            let rawLength = req.headers["Content-Length"].first,
            let size = Int(rawLength),
            let stream = req.physique.stream
        else {
            throw HBHTTPError(
                .badRequest,
                message: "Lacking or invalid physique stream."
            )
        }
        var rely: Int = 0
        for strive await chunk in stream.sequence {
            rely += chunk.readableBytes
        }
        return String("(size) / (rely)")
    }
}


let app = HBApplication(
    configuration: .init(
        handle: .hostname(hostname, port: port),
        serverName: "Hummingbird",
        maxUploadSize: 1 * 1024 * 1024 * 1024 
    )
)

As you’ll be able to see you’ll be able to simply entry all of the incoming headers by way of the req.headers container, it is best to notice that this technique will return header values in a case-insensitive manner. If you wish to stream bigger information, you additionally should set a customized maxUploadSize utilizing the configuration object when initializing the HBApplication occasion.

curl -X POST http://localhost:8080/foo 
    -H "Content material-Size: 3" 
    --data-raw 'foo'

curl -X POST http://localhost:8080/foo 
    -H "content-Size: 5242880" 
    -T ~/check

You may check out streaming with a easy cURL script, be at liberty to experiment with these.

One other factor I might like to indicate you is find out how to entry question parameters and different properties utilizing the request object. Right here is an all-in-one instance, which you should use as a cheatsheet… 😉


router.get("bar") { req async throws -> String in
            
    struct Foo: Codable {
        var a: String
    }

    print(req.technique)
    print(req.headers)
    print(req.headers["accept"])
    print(req.uri.queryParameters.get("q") ?? "n/a")
    print(req.uri.queryParameters.get("key", as: Int.self) ?? 0)

    if let buffer = req.physique.buffer {
        let foo = strive? JSONDecoder().decode(Foo.self, from: buffer)
        print(foo ?? "n/a")
    }
    return "Hiya, world!"
}

Anyway, there’s one further tremendous cool characteristic in Hummingbird that I might like to indicate you. It’s potential to outline a route handler, this fashion you’ll be able to encapsulate all the things right into a single object. There’s an async model of the route handler protocol, for those who do not want async, you’ll be able to merely drop the key phrase each from the protocol title & the strategy. I really like this method so much. 😍

struct MyRouteHandler: HBAsyncRouteHandler {

    struct Enter: Decodable {
        let foo: String
    }

    struct Output: HBResponseEncodable {
        let id: String
        let foo: String
    }
    
    let enter: Enter

    init(from request: HBRequest) throws {
        self.enter = strive request.decode(as: Enter.self)
    }

    func deal with(request: HBRequest) async throws -> Output {
        .init(
            id: "id-1",
            foo: enter.foo
        )
    }
}

The request.decode technique makes use of the built-in decoder, which you must explicitly set for the applying, since we will talk utilizing JSON knowledge, we are able to use the JSON encoder / decoder from Basis to routinely remodel the info.

In an effort to make use of the customized route handler, you’ll be able to merely register the thing kind.

import Hummingbird
import HummingbirdFoundation

public extension HBApplication {

    func configure() throws {
        
        encoder = JSONEncoder()
        decoder = JSONDecoder()
                
        
        router.put up("foo", use: MyRouteHandler.self)
    }
}

You may learn extra about how the encoding and decoding works in Hummingbird, however possibly that subject deserves its personal weblog put up. When you have questions or recommendations, be at liberty to contact me. 🙈

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