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 test further parameters and headers to construct the ultimate response, however once we speak about routing usually, we normally confer 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 possibly can 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.publish("foo") { _ -> HTTPResponseStatus in .okay }
router.patch("foo") { _ -> HTTPResponseStatus in .okay }
router.delete("foo") { _ -> HTTPResponseStatus in .okay }

In Hummingbird additionally it is attainable to register use a perform as an alternative of a block. Handler features will be async and throwing too, so you possibly can 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. πŸ‘

You can even prefix a path part with a colon, this can flip that part right into a dynamic route parameter. The parameter goes to be named after the trail part, by merely dropping the colon prefix. You may entry parameters inside your route handler via the req.parameters property. It is usually attainable to register a number of parts utilizing a / character.

public extension HBApplication {
    
    func configure() throws {

        router.get { _ async throws in "Hi there, 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 "Hi there, (title)!"
        }

        let group = router.group("todos")
        group.get(use: record)
        group.publish(use: create)
        
        let idGroup = group.group(":todoId")
        idGroup.head(use: test)
        idGroup.get(use: fetch)
        idGroup.put(use: replace)
        idGroup.patch(use: patch)
        idGroup.delete(use: delete)

        
        router.group("todos")
            .get(use: record)
            .publish(use: create)
            .group(":todoId")
                .head(use: test)
                .get(use: fetch)
                .put(use: replace)
                .patch(use: patch)
                .delete(use: delete)

    }

    func record(_ req: HBRequest) async throws -> HTTPResponseStatus { .okay }
    func test(_ 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 attainable to make use of a wildcard character () when detecting path parts and the recursive model (*) to catch all the pieces. Additionally you should use the ${title} syntax to catch a named request parameter even with a prefix or suffix, however you possibly can’t insert this in the midst of a path part. (e.g. “prefix-${title}.jpg” will not work, however “${title}.jpg” is simply wonderful) πŸ’‘

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")
    }
}

It is usually attainable to edit the auto-generated response in case you specify the .editResponse choice.

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

Hummingbird help for physique streaming is superb, you possibly can stream a HTTP request physique through the use of the .streamBody choice. The physique stream has a sequence property, which you should use to iterate via the incoming ByteBuffer chunks when dealing with the request. πŸ”„

func configure() throws { 
    router.publish("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 attempt await chunk in stream.sequence {
            rely += chunk.readableBytes
        }
        return String("(size) / (rely)")
    }
}


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

As you possibly can see you possibly can simply entry all of the incoming headers by way of the req.headers container, it is best to observe that this technique will return header values in a case-insensitive manner. If you wish to stream bigger information, you additionally must 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 point out you is how one can 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… πŸ˜‰


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 = attempt? JSONDecoder().decode(Foo.self, from: buffer)
        print(foo ?? "n/a")
    }
    return "Hi there, world!"
}

Anyway, there’s one further tremendous cool characteristic in Hummingbird that I might like to point out you. It’s attainable to outline a route handler, this fashion you possibly can encapsulate all the pieces right into a single object. There may be an async model of the route handler protocol, in case you do not want async, you possibly can merely drop the key phrase each from the protocol title & the tactic. I like this method rather a lot. 😍

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 = attempt 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 it’s a must to 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 rework the information.

In an effort to make use of the customized route handler, you possibly can merely register the article kind.

import Hummingbird
import HummingbirdFoundation

public extension HBApplication {

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

You may learn extra about how the encoding and decoding works in Hummingbird, however perhaps that subject deserves its personal weblog publish. In case you have questions or solutions, be at liberty to contact me. πŸ™ˆ

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