How can I parse out get request parameters in spray-routing?

Question

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

score 30 · Accepted Answer · edited Dec 30 '16 at 15:10

30

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) => 
      ...
    }
  }
}

edited Dec 30 '16 at 15:10

Matthias Braun

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answered Nov 16 '13 at 06:59

4lex1v

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Thanks, this is cleaner. – Kevin Colin Dec 03 '13 at 19:09
1

Note that on Spray 1.2 it would be `parameters('q, 'filter ? "all")` – Samy Dindane Feb 17 '14 at 15:31
@SamyDindane it doesn't matter, `NameReplacable` defined for strings as well as for symbols – 4lex1v Feb 18 '14 at 06:09
What's the purpose of `"filter" ? "all"`? Could you please give an example? Thanks – Kevin Meredith Jun 30 '15 at 16:32
1

@KevinMeredith Read it like `getOrElse` for the `Option` type. If there's no `filter` parameter in the request, the value for it will be `all` – 4lex1v Jun 30 '15 at 16:34
Thanks. Also, you don't need to specify the query parameters' types? In your example, are the query parameters, `q` and `filter` assumed to be of type `String` since you did not specify a type? – Kevin Meredith Jun 30 '15 at 17:04
using the latest akka 2.4.3 I get error when typing this code: `too many arguments for method parameters`. What has changed? Are the docs outdated? – ecoe Apr 09 '16 at 18:16
@ecoe nothing, just checked and works fine, I bet you've missed some imports or the types are wrong – 4lex1v Apr 09 '16 at 18:19
@4lex1v missed what imports? Could the code sample in your solution please explicitly define the necessary imports? I have a get request working perfectly, so if there are other implicit imports I need that is news to me and not discussed at all in the docs. Thanks for the quick response. – ecoe Apr 09 '16 at 18:31
2

@ecoe In fact you are right, this sample is wrong in that you need to provide a required value for `!`, like `'q ! "default"`, which is required. I believe this is your problem – 4lex1v Apr 09 '16 at 18:45

How can I parse out get request parameters in spray-routing?

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