.ruleForEachTransformed

The .ruleForEachTransformed method on the Validator class is identical to the .ruleForEach method, except that it allows you to transform each item of the given array property on your model via a transformation function prior to building up the rule chain for it.

The available validation rules will be based on the type of the transformed items, rather than the original type of the items.

To get started, simply call this.ruleForTransformed in the constructor of your validator and pass in the name of an array property on your model, along with a transformation function.

The result of this call is a rule chain builder, exactly the same as that returned by .ruleForEach, except that it exposes all the relevant built-in validation rules for the type of the transformed item values.

import { Validator } from 'fluentvalidation-ts';

type FormModel = {
  scores: Array<string>;
};

class FormValidator extends Validator<FormModel> {
  constructor() {
    super();

    this.ruleForEachTransformed('scores', (s) => Number(s))
      .must((numberScore) => !isNaN(numberScore))
      .greaterThan(0)
      .lessThanOrEqualTo(100);
  }
}

Limitations

The same limitations that apply to the .ruleForTransformed method apply also to the .ruleForEachTransformed method.