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.
Related
I want to validate REST requests (GET and PUT) in LIFT before processing it. i.e. i need to check whether requests has a parameter requestor. if not need to response with exception saying missing parameter. Could you please let me know how to do this.
There are a few things you could do. The two I would try would be a helper function that would wrap your Rest call, something like:
def checkParam(r:Req):Boolean = {
r.param("paramName").isDefined
}
def requireParams[T<:LiftResponse](r:Req)(methodBody: => T):LiftResponse = {
if(checkParam(r))
methodBody
else
InMemoryResponse("Parameters not specified".getBytes(), List("content-type" -> "text/plain"), Nil, 500)
}
The function will check for the parameters and return an error if it doesn't work, or execute the call if it does. In your Rest call, you would use it like:
case "location" :: Nil Get req => requireParams(req){
//your rest body
}
Alternately, you could probably use a guard on the entire RestHelper assuming you wanted to check every method call, something like this might work:
val ensureParams: PartialFunction[Req, Unit] = {
case r if (r.get_? || r.put_?) && checkParam(r) =>
case r if (!r.get_? && !r.put_?) =>
}
and then guard your RestHelper instance in Boot with:
LiftRules.dispatch.append(ensureParams guard YourRestHelper)
I haven't tested the above code, so there may be some mistakes - but hopefully it should help get you started.
I know akka-http libraries marshal and unmarshal to class type while processing request.But now, I need to read request-parameters of GET request. I tried parameter() method and It is returning ParamDefAux type but i need those values as strings types
I check for answer at below questions.
How can I parse out get request parameters in spray-routing?
Query parameters for GET requests using Akka HTTP (formally known as Spray)
but can't do what i need.
Please tell me how can i extract query parameters from request. OR How can I extract required value from ParamDefAux
Request URL
http://host:port/path?key=authType&value=Basic345
Get method definition
val propName = parameter("key")
val propValue = parameter("value")
complete(persistanceMgr.deleteSetting(propName,propValue))
My method declarations
def deleteSetting(name:String,value:String): Future[String] = Future{
code...
}
For a request like http://host:port/path?key=authType&value=Basic345 try
path("path") {
get {
parameters('key.as[String], 'value.as[String]) { (key, value) =>
complete {
someFunction(key,value)
}
}
}
}
Even though being less explicit in the code, you can also extract all the query parameters at once from the context. You can use as follows:
// Previous part of the Akka HTTP routes ...
extract(_.request.uri.query()) { params =>
complete {
someFunction(key,value)
}
}
If you wish extract query parameters as one piece
extract(ctx => ctx.request.uri.queryString(charset = Charset.defaultCharset)) { queryParams =>
//useyourMethod()
}
I am currently using Gatling and I have a scenario whereby I perform a number of GET requests and depending on the body of the responses I would like to perform a different scenario.
I have this at the moment that doesn't appear to work as expected -
val repeatSpin = scenario("repeatScenario1").repeat(10) {
exec(
scenario1
)
.doIf(bodyString => bodyString.equals("<SwitchEvent/>")){
exec(scenario2)
}
}
What am I doing wrong?
It looks like you've got the .doIf parameters wrong - it either takes a key in the session and the value you expect, like:
.doIf("${bodyString}", "<SwitchEvent/>") { myChain }
Or, an Expression[Boolean] - the argument you get is the session; to get values out of a session you do something like session("bodyString").as[String]. So, passing a function to the doIf could look like
.doIf(session => session("bodyString").as[String].equals("<SwitchEvent/>")) { myChain }
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) =>
...
}
}
}
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.