Return from function in body and not only in last line in REST API Scala and play

Question

I develop Rest API with scala and play framework.

In my product controller, I do validation of parameters received.
In case they fail from some reason, I would like to response with BadRequest in the middle of the function and not in the last line as scala works..
In the code below - Code continues running to the Ok line.. which is wrong, I want to return !

def getProduct(lang: String, t: String, ids: String) = Action {
 val productIdsList =  ids.split(",").toList 

 if (productIdsList.length.equals(1) && productIdsList(0).equals("")) //Validate input params are product Ids and not empty !
 {
    var errorResponse:ErrorResponse[String] = ErrorResponse(ErrorCode.GeneralError, "No products IDs", 500)
    BadRequest(Json.toJson(errorResponse))//maybe return BadRequest(Json.toJson(errorResponse) ??
 }              

 val results = productService.getProducts(GetProductsRequest(lang,t,productIdsList));
 Ok(Json.toJson(results)) 
 // TODO: handle error
}

If implemented as:

return BadRequest(...)

It reply with error:

"method getProduct has return statement; needs result type"  

I Understand this is bad practice, so what is the best practice for quitting the function without finishing it (and not throwing exceptions..)

Answer 1

Just put an else branch, so there's nowhere to continue:

def getProduct(lang: String, t: String, ids: String) = Action {
 val productIdsList =  ids.split(",").toList 

 if (productIdsList.length.equals(1) && productIdsList(0).equals("")){ //Validate input params are product Ids and not empty !
    var errorResponse:ErrorResponse[String] = ErrorResponse(ErrorCode.GeneralError, "No products IDs", 500)
    BadRequest(Json.toJson(errorResponse))//maybe return BadRequest(Json.toJson(errorResponse) ??
 }else{
    val results = productService.getProducts(GetProductsRequest(lang,t,productIdsList));
    Ok(Json.toJson(results)) 
    // TODO: handle error
 }
}