Using a top-level function for a handler in Kotlin

To create a handler in Kotlin, you can set a top-level function. This is a function declared within a package and requiring no class for its creation.

Here is an example of a handler that accepts a number and returns it:

fun handle(s: Int): Int = s

You can test the function from the above example in the following ways:

• In the management console, on the Testing tab of the function page.

• Using the following HTTPS request with the ?integration=raw parameter:

  curl \
       --header "Authorization: Bearer <IAM_token>" \
       --data "<number>" \
       "https://functions.yandexcloud.net/<function_ID>?integration=raw"
  

  In the --data parameter, specify the function’s return value.

ExamplesExamples

Processing an HTTP requestProcessing an HTTP request

The script below processes an incoming HTTP request and outputs the results: the HTTP status code and the response body.

Handler.kt:

data class Request(
    val httpMethod: String?,
    val headers: Map<String, String> = mapOf(),
    val body: String = ""
)

data class Response(
    val statusCode: Int,
    val body: String
)

fun handle(request: Request): Response {
    return Response(200, "Hello World!")
}

The result format depends on whether the user provided ?integration=raw in the request:

• If ?integration=raw was provided:

  {
      "statusCode": 200,
      "body": "Hello World!"
  }
  

• If ?integration=raw was not provided:

  "Hello World!"
  

  The 200 code will be returned not as part of the response body, as with the ?integration=raw parameter, but as the HTTP status code.

HTTP request structure outputHTTP request structure output

The script below processes an incoming HTTP request and outputs its structure and the HTTP status code.

Handler.kt:

data class Response(
    val statusCode: Int,
    val body: String
)

fun handle(request: String): Response {
    return Response(200, request)
}