failIf

failIf<T>(value: T, evaluator: (value: T) -> Boolean, message: String = 'Failed'): T

Produces an error with the specified message if the expression in the evaluator returns true. Otherwise, the function returns the value.

Parameters

Name Description

Name	Description
`value`	The value to return only if the `evaluator` expression is `false`.
`evaluator`	Expression that returns `true` or `false`.

value

The value to return only if the evaluator expression is false.

evaluator

Expression that returns true or false.

Example

This example produces a runtime error (instead of a SUCCESS message) because the expression isEmpty(result) is true. It is true because an empty object is passed through variable result.

Source

%dw 2.0
import failIf from dw::Runtime
var result = {}
output application/json
---
{ "result" : failIf(result, isEmpty) }

Output

ERROR 2018-07-29 11:56:39,988 ...
**********************************
Message               : "Failed

Alternatively, the function outputs the value.

Source

%dw 2.0
import failIf from dw::Runtime
var result = {"a":"test"}
output application/json
---
{ "result" : result failIf isEmpty($) }

Output

{
  "result": {
    "a": "test"
  }
}