For iteration on scalatra input

Question

I am trying to read input in scalatra webapp using for iteration in below manner

for (
         input1<- params.getOrElse("input1", "");
         input2 <- params.getOrElse("input2", "");
         search <- params.getOrElse("search", false)
    ) {
       //Perform action
    }

It is throwing error value foreach is not a member of Object.

In case if user doesn't provide any input, it should default empty string and call the action instead of breaking out of loop. For that reason i am using getOrElse. But i haven't succeeded.

Any help?

What is the type of `params`? I guess it's a `Map[String, Something]`, so you should replace `input1 <- params.getOrElse(...)` with `val input1 = params.getOrElse(...)` (same for `input2` and `search`) and remove `for`, but you'll get values of type `Any` since you are using different types in `getOrElse` (`String` and `Boolean`). — senia, Dec 23 '13 at 17:51

score 1 · Accepted Answer · answered Dec 23 '13 at 17:57

You can use for-comprehensions to work with Option but you can't use it for objects that don't have at least one defined foreach, map or flatMap. In your case, if params is returning options then...

for(
  input1 <- params get "input1"
  input2 <- params get "input2"
 ){
   //do stuff
 }

Wherein this will not run if both input and input2 are not None.

If you don't want to short circuit the control logic and you want there to be sane defaults for Option returns, then a better way is just to do

 myFunction(params getOrElse ("input1", "default1"), params getOrElse ("input2", 42))

where you're explicitly providing the defaults and passing them into a function call.

Don't you think that `val input1 = params.getOrElse("input1", "")` is what OP wants. — senia, Dec 23 '13 at 18:01
@senia No. He's doing a side-effecting operation with the results. There's no need to store the value once passed into the function. — wheaties, Dec 23 '13 at 18:02

For iteration on scalatra input

1 Answers1