validate

README

github.com/markbates/going/validate

This package provides a framework for writing validations for Go applications. It does not, however, provide you with any actual validators, that part is up to you.

Installation

$ go get https://github.com/markbates/validate

Usage

Using validate is pretty easy, just define some Validator objects and away you go.

Here is a pretty simple example:

package main

import (
	"log"

	v "github.com/markbates/going/validate"
)

type User struct {
	Name  string
	Email string
}

func (u *User) IsValid(errors *v.ValidationErrors) {
	if u.Name == "" {
		errors.Add("name", "Name must not be blank!")
	}
	if u.Email == "" {
		errors.Add("email", "Email must not be blank!")
	}
}

func main() {
	u := User{Name: "", Email: ""}
	errors := v.Validate(&u)
	log.Println(errors.Errors)
  // map[name:[Name must not be blank!] email:[Email must not be blank!]]
}

In the previous example I wrote a single Validator for the User struct. To really get the benefit of using go-validator, as well as the Go language, I would recommend creating distinct validators for each thing you want to validate, that way they can be run concurrently.

package main

import (
	"fmt"
	"log"
	"strings"

	v "github.com/markbates/going/validate"
)

type User struct {
	Name  string
	Email string
}

type PresenceValidator struct {
	Field string
	Value string
}

func (v *PresenceValidator) IsValid(errors *v.ValidationErrors) {
	if v.Value == "" {
		errors.Add(strings.ToLower(v.Field), fmt.Sprintf("%s must not be blank!", v.Field))
	}
}

func main() {
	u := User{Name: "", Email: ""}
	errors := v.Validate(&PresenceValidator{"Email", u.Email}, &PresenceValidator{"Name", u.Name})
	log.Println(errors.Errors)
  // map[name:[Name must not be blank!] email:[Email must not be blank!]]
}

That's really it. Pretty simple and straight-forward Just a nice clean framework for writing your own validators. Use in good health.

Documentation

Index

• type Errors
  • func NewErrors() *Errors
  • func Validate(validators ...Validator) *Errors
  • func (v *Errors) Add(key string, msg string)
  • func (v *Errors) Append(ers *Errors)
  • func (v *Errors) Count() int
  • func (v *Errors) Get(key string) []string
  • func (v *Errors) HasAny() bool
  • func (v *Errors) String() string
• type Validator

Types

type Errors

type Errors struct {
	Errors map[string][]string `json:"errors"`
	Lock   *sync.RWMutex       `json:"-"`
}

Errors holds onto all of the error messages that get generated during the validation process.

func NewErrors

func NewErrors() *Errors

NewErrors returns a pointer to a Errors object that has been primed and ready to go.

func Validate

func Validate(validators ...Validator) *Errors

Validate takes in n number of Validator objects and will run them and return back a point to a Errors object that will contain any errors.

func (*Errors) Add

func (v *Errors) Add(key string, msg string)

Add will add a new message to the list of errors using the given key. If the key already exists the message will be appended to the array of the existing messages.

func (*Errors) Append

func (v *Errors) Append(ers *Errors)

Append concatenates two Errors objects together. This will modify the first object in place.

func (*Errors) Count

func (v *Errors) Count() int

Count returns the number of errors.

func (*Errors) Get

func (v *Errors) Get(key string) []string

Get returns an array of error messages for the given key.

func (*Errors) HasAny

func (v *Errors) HasAny() bool

HasAny returns true/false depending on whether any errors have been tracked.

func (*Errors) String

func (v *Errors) String() string

type Validator

type Validator interface {
	IsValid(errors *Errors)
}

Validator must be implemented in order to pass the validator object into the Validate function.