scala: how to rewrite this function using for comprehension

Posted by opensas on Stack Overflow See other posts from Stack Overflow or by opensas
Published on 2012-10-30T16:16:18Z Indexed on 2012/10/30 17:01 UTC
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scala

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for-comprehension

I have this piece of code with a couple of nasty nested checks...

I'm pretty sure it can be rewritten with a nice for comprehension, but I'm a bit confused about how to mix the pattern matching stuff

// first tries to find the token in a header: "authorization: ideas_token=xxxxx"
// then tries to find the token in the querystring: "ideas_token=xxxxx"
private def applicationTokenFromRequest(request: Request[AnyContent]): Option[String] = {

  val fromHeaders: Option[String] = request.headers.get("authorization")
  val tokenRegExp = """^\s*ideas_token\s*=\s*(\w+)\s*$""".r

  val tokenFromHeader: Option[String] = {
    if (fromHeaders.isDefined) {
      val header = fromHeaders.get
      if (tokenRegExp.pattern.matcher(header).matches) {
        val tokenRegExp(extracted) = header
        Some(extracted)
      } else {
        None
      }
    } else {
      None
    }
  }

  // try to find it in the queryString
  tokenFromHeader.orElse {
    request.queryString.get("ideas_token")
  }

}

any hint you can give me?

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