Rules operators

Regle provides tools to combine and operate on different rules. It includes four built-in operators, available in @regle/rules:

• and
• or
• not
• applyIf
• assignIf

These operators work with any rules you provide, but combining rules with incompatible input types may lead to errors.

TIP

All operators are compatible with wrappers

and

The and operator combines multiple rules and validates successfully only if all provided rules are valid.

import { useRegle } from '@regle/core';
import { and, startsWith, endsWith, withMessage } from '@regle/rules';

const { r$ } = useRegle(
  { regex: '' },
  {
    regex: {
      myError: withMessage(
        and(startsWith('^'), endsWith('$')),
        ({ $params: [start, end] }) =>
          `Regex should start with "${start}" and end with "${end}"`
      ),
    },
  }
);

Result:

or

The or operator validates successfully if at least one of the provided rules is valid.

import { useRegle } from '@regle/core';
import { or, startsWith, endsWith, withMessage } from '@regle/rules';

const { r$ } = useRegle(
  { regex: '' },
  {
    regex: {
      myError: withMessage(
        or(startsWith('^'), endsWith('$')),
        ({ $params: [start, end] }) =>
          `Field should start with "${start}" or end with "${end}"`
      ),
    },
  }
);

Result:

not

The not operator passes when the provided rule fails and fails when the rule passes. It can be combined with other rules.

import { useRegle } from '@regle/core';
import { not, required, sameAs, withMessage } from '@regle/rules';
import { ref } from 'vue';

const form = ref({ oldPassword: '', newPassword: '' });
const { r$ } = useRegle(form, {
  oldPassword: {
    required,
  },
  newPassword: {
    notEqual: withMessage(
      not(sameAs(() => form.value.oldPassword)),
      'Your confirm new password must not be the same as your old password'
    ),
  },
});

Result:

applyIf

The applyIf operator is similar to requiredIf, but it can be used with any rule. It simplifies conditional rule declarations.

import { minLength, applyIf } from '@regle/rules';

const condition = ref(false);

const { r$ } = useRegle({name: ''}, {
  name: {
    minLength: applyIf(condition, minLength(6))
  },
});

Require min length of 6

assignIf

The assignIf is a shorthand for conditional destructuring assignment. It allows to apply multiple rules to a field conditionally.

import { required, email, minLength, assignIf } from '@regle/rules';

const condition = ref(false);

const { r$ } = useRegle(ref({ name: '', email: '' }), {
  name: assignIf(condition, { required, minLength: minLength(4) }),
  email: { email },
});