I want to create a route that matches only if the client sends a specific Accept header. I use Spray 1.2-20130822.
I'd like to get the route working:
def receive = runRoute {
get {
path("") {
accept("application/json") {
complete(...)
}
}
}
}
Here I found a spec using an accept() function, but I can't figure out what to import in my Spray-Handler to make it work as directive. Also, I did not find other doc on header directives but these stubs.
I would do this way:
def acceptOnly(mr: MediaRange*): Directive0 =
extract(_.request.headers).flatMap[HNil] {
case headers if headers.contains(Accept(mr)) ⇒ pass
case _ ⇒ reject(MalformedHeaderRejection("Accept", s"Only the following media types are supported: ${mr.mkString(", ")}"))
} & cancelAllRejections(ofType[MalformedHeaderRejection])
Then just wrap your root:
path("") {
get {
acceptOnly(`application/json`) {
session { creds ⇒
complete(html.page(creds))
}
}
}
}
And by the way the latest spray 1.2 nightly is 1.2-20130928 if you can, update it
There is no pre-defined directive called accept directive. You can see the full list of available directives here.
However, you can use the headerValueByName directive to make a custom directive that does what you desire:
def accept(required: String) = headerValueByName("Accept").flatMap {
case actual if actual.split(",").contains(required) => pass
case _ => reject(MalformedHeaderRejection("Accept", "Accept must be equal to " + required))
}
Put this code in scope of your spray Route, then just use as you have shown in your question.
Related
I am new to spray and I am trying to write a custom directive. I would like the directive to reject the request if the header value is not valid otherwise leave the request alone.
I've tried to absorb this page:
http://spray.io/documentation/1.1.2/spray-routing/key-concepts/directives/
Specifically, the part about the responder chain. I'm trying to create something at the level of the bar Directive in the illustration. I'm just not getting how to pass the context unchanged to the inner route.
My else block below is not correct but expresses what I am trying to do. I just can't figure out how to implement it.
Any help would be greatly appreciated.
trait ApiKeyDirective {
import spray.routing.directives.HeaderDirectives._
import spray.routing.directives.BasicDirectives._
def validateApiKey(): Directive1 = {
headerValueByName("api-key") {key =>
val valid = key == "123"
if (!valid) reject() else pass
}
}
}
object ApiKeyDirective extends ApiKeyDirective
You can combine
headerValueByName:
def headerValueByName(headerName: String): Directive1[String]
with validate:
def validate(check: ⇒ Boolean, errorMsg: String): Directive0
For example:
def validateApiKey(route: Route) =
headerValueByName("api-key") { key =>
validate(key == "123", "Invalid API key") {
route
}
}
or without validate:
def validateApiKey(route: Route) =
headerValueByName("api-key") { key =>
if (key == "123")
route
else
reject(ValidationRejection("Invalid API key"))
}
Usage:
lazy val route = ...
... ~
pathPrefix("test_directive") {
get {
validateApiKey {
complete("ok")
}
}
} ~
...
Test from cmd/shell:
# curl http://localhost:8080/test_directive
Request is missing required HTTP header 'api-key'
# curl http://localhost:8080/test_directive -H 'api-key: bad'
Invalid API key
# curl http://localhost:8080/test_directive -H 'api-key: 123'
"ok"
I'm just not getting how to pass the context unchanged to the inner
route.
Spray does that for you!
Your code is mostly correct, there are just 2 simple problems to fix!
Firstly, you need to flatMap headerValueByName("api-key") directive.
Secondly, the return type will be Directive0 because the directive won't provide any value.
So final code would look like this:
object ApiKeyDirective {
import spray.routing.Directives._
val validateApiKey: Directive0 =
headerValueByName("api-key").flatMap { key =>
val valid = key == "123"
if (!valid) reject() else pass
}
}
Also, I recommend you to add a custom rejection to reject() block so that API users will be informed when their api key is invalid.
I'm designing a REST service using Akka-HTTP 2.0-M2 and have come across a situation where I'd like to supply additional headers which are dependent upon the reply of the queried Actor.
Currently, I have the following...
val route = {
path("oncologist") {
get {
parameters('active.as[Boolean].?, 'skip.as[Int].?, 'limit.as[Int].?).as(GetAllOncologists) {
req =>
complete {
(oncologistActor ? req).mapTo[OncologistList]
}
}
}
}
While this is returning without issue. I'd like to move some of the properties of OncologistList into the response header rather than returning them in the body. Namely, I'm returning total record counts and offset and I would like to generate a previous and next URL header value for use by the client. I'm at a loss on how to proceed.
I think you can use the onComplete and respondWithHeaders directives to accomplish what you want. The onComplete directive works with the result of a Future which is exactly what ask (?) will return. Here is an example using a case class like so:
case class Foo(id:Int, name:String)
And a simple route showing onComplete like so:
get{
parameters('active.as[Boolean].?, 'skip.as[Int].?, 'limit.as[Int].?).as(GetAllOncologists) { req =>
val fut = (oncologistActor ? req).mapTo[Foo]
onComplete(fut){
case util.Success(f) =>
val headers = List(
RawHeader("X-MyObject-Id", f.id.toString),
RawHeader("X-MyObject-Name", f.name)
)
respondWithHeaders(headers){
complete(StatusCodes.OK)
}
case util.Failure(ex) =>
complete(StatusCodes.InternalServerError )
}
}
}
So if we get a successful result from the ask on oncologistActor we can then leverage the respondWithHeaders to add some custom headers to the response. Hopefully this is what you were looking for.
I've a route as follows:
val route = {
logRequestResult("user-service") {
pathPrefix("user") {
get {
respondWithHeader(RawHeader("Content-Type", "application/json")) {
parameters("firstName".?, "lastName".?).as(Name) { name =>
findUserByName(name) match {
case Left(users) => complete(users)
case Right(error) => complete(error)
}
}
}
} ~
(put & entity(as[User])) { user =>
complete(Created -> s"Hello ${user.firstName} ${user.lastName}")
} ~
(post & entity(as[User])) { user =>
complete(s"Hello ${user.firstName} ${user.lastName}")
} ~
(delete & path(Segment)) { userId =>
complete(s"Hello $userId")
}
}
}
}
The content type of my response should always be application/json as I've it set for the get request. However, what I'm getting in my tests is text/plain. How do I set the content type correctly in the response?
On a side note, the akka-http documentation is one of the most worthless piece of garbage I've ever seen. Almost every link to example code is broken and their explanations merely state the obvious. Javadoc has no code example and I couldn't find their codebase on Github so learning from their unit tests is also out of the question.
I found this one post that says "In spray/akka-http some headers are treated specially". Apparently, content type is one of those and hence can't be set as in my code above. One has to instead create an HttpEntity with the desired content type and response body. With that knowledge, when I changed the get directive as follows, it worked.
import akka.http.scaladsl.model.HttpEntity
import akka.http.scaladsl.model.MediaTypes.`application/json`
get {
parameters("firstName".?, "lastName".?).as(Name) { name =>
findUserByName(name) match {
case Left(users) => complete(users)
case Right(error) => complete(error._1, HttpEntity(`application/json`, error._2))
}
}
}
This is what the section of code looks like
get{
respondWithMediaType(MediaTypes.`application/json`){
entity(as[HttpRequest]){
obj => complete{
println(obj)
"ok"
}
}
}
}~
I can map the request to a spray.http.HttpRequest object and I can extract the uri from this object but I imagine there is an easier way to parse out the parameters in a get request than doing it manually.
For example if my get request is
http://localhost:8080/url?id=23434&age=24
I want to be able to get id and age out of this request
Actually you can do this much much better. In routing there are two directives: parameter and parameters, I guess the difference is clear, you can also use some modifiers: ! and ?. In case of !, it means that this parameter must be provided or the request is going to be rejected and ? returns an option, so you can provide a default parameter in this case. Example:
val route: Route = {
(path("search") & get) {
parameter("q"!) { query =>
....
}
}
}
val route: Route = {
(path("search") & get) {
parameters("q"!, "filter" ? "all") { (query, filter) =>
...
}
}
}
In Rails, I was able to do something similar to the following:
respond_to do |format|
format.xml { ... }
format.json { ... }
end
and the appropriate block would be executed based on what the client supplied in the Accept header.
How can I do the same thing in Play 2.0 (Scala)?
I'd look to do something that looks roughly like this:
try {
Resources.delete(id)
Ok("done")
}
catch {
case e: ClientReportableException =>
?? match {
case "application/xml" => Ok(<error>{e.message}</error>)
case "application/json" => Ok(...)
}
}
Is there a Play idiom for this, or do I just fetch the value of the Accept header from the request?
In Play 2.1 you can write the following:
request match {
case Accepts.Xml() => Ok(<error>{e.message}</error>)
case Accepts.Json() => Ok(…)
}
The cases statements are tried in the order they are written, so if your client sets the HTTP Accept header to */* the first one will match (in this example case Accepts.Xml()). So, you usually want to write the Accepts.Html() case first because browsers set the Accept header to */*.
(Note: you may also be interested in this answer for a similar question in Java)
I have just released a Play! 2.0 module for content negotiation called mimerender (http://github.com/martinblech/play-mimerender).
The idea is that you have to define a mapping from your domain classes to different representations:
val m = mapping(
"text/html" -> { s: String => views.html.index(s) },
"application/xml" -> { s: String => <message>{s}</message> },
"application/json" -> { s: String => toJson(Map("message" -> toJson(s))) },
"text/plain" -> identity[String]_
)
Once you have done that once, you can reuse that mapping throughout all your controllers:
object Application extends Controller {
def index = Action { implicit request =>
m.status(200)("Hello, world!")
}
}
Please note it's a very early release and has only been tested on Play 2.0.4