Rules

Rules are the core concept of Regle (and also it's name 🙄).

A rule is created using either:

• An inline function
• createRule

A rule takes the value (and optional parameters) as input and returns a result as output.

The result can either be:

• boolean
• An object containing at least the { $valid: boolean } property.

The boolean represents the result of the validation.

TIP

You can jump directly to the createRule section to see more advanced features.

Inline rules

You can write inline rules as simple functions that receive the value being evaluated as a parameter. Use the InlineRuleDeclaration type helper for enhanced type safety.

import type { Maybe, InlineRuleDeclaration } from '@regle/core';

const customRuleInline = (value: Maybe<string>) => value === 'regle';

/** Async rule that will activate the $pending state of your field  */
const customRuleInlineAsync = async (value: Maybe<string>) => {
  return await someAsyncCall();
};

/** You can return any data from your rule as long as the $valid property is present  */
const customRuleInlineWithMetaData = ((value: Maybe<string>) => ({
  $valid: value === 'regle',
  foo: 'bar'
})) satisfies InlineRuleDeclaration;