niki/vendor/github.com/go-ozzo/ozzo-validation/each.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"
	"reflect"
	"strconv"
)

// Each returns a validation rule that loops through an iterable (map, slice or array)

// and validates each value inside with the provided rules.

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

func Each(rules ...Rule) *EachRule {

	return &EachRule{

		rules: rules,
	}

}

type EachRule struct {
	rules []Rule
}

// Loops through the given iterable and calls the Ozzo Validate() method for each value.

func (r *EachRule) Validate(value interface{}) error {

	errs := Errors{}

	v := reflect.ValueOf(value)

	switch v.Kind() {

	case reflect.Map:

		for _, k := range v.MapKeys() {

			val := r.getInterface(v.MapIndex(k))

			if err := Validate(val, r.rules...); err != nil {

				errs[r.getString(k)] = err

			}

		}

	case reflect.Slice, reflect.Array:

		for i := 0; i < v.Len(); i++ {

			val := r.getInterface(v.Index(i))

			if err := Validate(val, r.rules...); err != nil {

				errs[strconv.Itoa(i)] = err

			}

		}

	default:

		return errors.New("must be an iterable (map, slice or array)")

	}

	if len(errs) > 0 {

		return errs

	}

	return nil

}

func (r *EachRule) getInterface(value reflect.Value) interface{} {

	switch value.Kind() {

	case reflect.Ptr, reflect.Interface:

		if value.IsNil() {

			return nil

		}

		return value.Elem().Interface()

	default:

		return value.Interface()

	}

}

func (r *EachRule) getString(value reflect.Value) string {

	switch value.Kind() {

	case reflect.Ptr, reflect.Interface:

		if value.IsNil() {

			return ""

		}

		return value.Elem().String()

	default:

		return value.String()

	}

}