_{Official ZPE/YASS documentation}input_validate

input_validate (function f, string failure_message, [integer max_times]) ⇒ string

Runs a standard input validation algorithm that will wait for the user to enter a valid response. Using a lambda function or a function call, this method can use a custom validation tool. If the max_times parameter is set, the validation will run a maximum of that number of times before stopping and throwing an invalid input error.

Examples

The following examples demonstrate this function:

function check($x)
  if ($x == "password")
    return true
  else
    return false
  end if
end function
$v = input_validate(handle_of(check), "Incorrect password.")

print($v)
    

The next example use input validation to check that a number is within a range:

$num = input_validate(
  function($x)
    $x = value($x)
    if ($x > 10 && $x < 100)
      return true
    else
      return false
    end if
  end function
, "Number must be between 10 and 100.")

print($num)
    

This example, submitted to me by one of the testers, was based on something she had written before that inspired this and uses regexps:

$name = input_validate(
  function($x)
    if (string_matches($x, "[A-Z][a-z]+"))
      return true
    else
      return false
    end if
  end function
, "Name must start with a capital and contain at least one lower case character after.")

print($name)