niki/vendor/github.com/go-ozzo/ozzo-validation/match.go

// Copyright 2016 Qiang Xue. All rights reserved.

// Use of this source code is governed by a MIT-style

// license that can be found in the LICENSE file.

package validation

import (
	"errors"
	"regexp"
)

// Match returns a validation rule that checks if a value matches the specified regular expression.

// This rule should only be used for validating strings and byte slices, or a validation error will be reported.

// An empty value is considered valid. Use the Required rule to make sure a value is not empty.

func Match(re *regexp.Regexp) *MatchRule {

	return &MatchRule{

		re: re,

		message: "must be in a valid format",
	}

}

type MatchRule struct {
	re *regexp.Regexp

	message string
}

// Validate checks if the given value is valid or not.

func (v *MatchRule) Validate(value interface{}) error {

	value, isNil := Indirect(value)

	if isNil {

		return nil

	}

	isString, str, isBytes, bs := StringOrBytes(value)

	if isString && (str == "" || v.re.MatchString(str)) {

		return nil

	} else if isBytes && (len(bs) == 0 || v.re.Match(bs)) {

		return nil

	}

	return errors.New(v.message)

}

// Error sets the error message for the rule.

func (v *MatchRule) Error(message string) *MatchRule {

	v.message = message

	return v

}