message: Make iterators value always strings.
  Engine supports strings only.
diff: @@ -123,7 +123,7 @@ export class TaskConfiguratorComponent implements OnDestroy {
  tile: this.currentTile,
  iterator: {
  isIterable,
  - iterableValue: isIterable ? MapperTranslator.parseExpression(this.iterableValue).value : undefined,
  + iterableValue: isIterable ? this.iterableValue : undefined,
  },
  inputMappings: MapperTranslator.translateMappingsOut(this.currentMappings),
  handlerId: this.flowId
  @@ -196,7 +196,7 @@ export class TaskConfiguratorComponent implements OnDestroy {
  this.createInputMapperConfig(eventData);
  this.iteratorModeOn = eventData.iterator.isIterable;
  - this.iterableValue = MapperTranslator.rawExpressionToString(eventData.iterator.iterableValue);
  + this.iterableValue = MapperTranslator.rawExpressionToString(eventData.iterator.iterableValue || '');
  this.initialIteratorData = {
  iteratorModeOn: this.iteratorModeOn,
  iterableValue: this.iterableValue,
  @@ -225,7 +225,7 @@ export class TaskConfiguratorComponent implements OnDestroy {
  mappings = this.currentTile.inputMappings;
  }
  - this.currentMappings = null;
  + this.currentMappings = MapperTranslator.translateMappingsIn(mappings);
  this.inputMappingsConfig = {
  inputScope: this.inputScope,
  propsToMap,
  