Go Struct Validator

Introduction

• The purpose of this project is to create error messages with proper structure that are easy for both users and developers to understand and use.
• Our goal is to provide error messages that include the name of the property in response and are simple to use in frontend applications, specifically in forms to display error messages for specific fields.
• This will help improve the user experience by making it easier for users to understand and resolve errors that may occur while using the system.

Installation

Use go get

go get -u github.com/shariarfaisal/validator

Import into your project

import "github.com/shariarfaisal/validator"

Tags

Tag	Description
required	Field is not empty or undefined
email	Email validity
date	Date format validity
min	Minimum value for number and minimum length for string value
max	Maximum value for number and maximum length for string value
enum	Is input data is enum
include	Is data contains or not in between given values
eq	Is data equal
ne	Is data not eqal
gt	Is data greater than
gte	Is data greater than or equal
lt	Is data less than
lte	Is data less than or equal
url	Is valid url
ip	Is valid ip address
ipv4	is valid ip address v4
item.[tag]	Map & slice items validation (Only for int value and strings types)

Functions

Func	Arguments	Description	Return
IsValidDate	(date string)	Check date's format validity	bool
IsValidEmail	(email string)	Check email validity	bool
IsValidURL	(url string)	Check url validity	bool
IsValidIP	(ip string)	Check ip address validity	bool
IsValidIpV4	(ip string)	Check ip address v4 validity	bool

Example

package main

import (
	"encoding/json"
	"fmt"
	"os"

	"github.com/shariarfaisal/validator"
)

type Address struct {
	Label string `json:"label" v:"enum=Home,Office"`
	Street string `json:"street" v:"required"`
	City string `json:"city" v:"required"`
}

type User struct {
	Name  string `json:"name" v:"required;min=3;max=20"`
	Age   int    `json:"age" v:"required;min=18;max=60"`
	Email string `json:"email" v:"required;email"`
	Addresses []Address `json:"addresses" v:"required;min=1;max=3"`
	DateOfBirth string `json:"dateOfBirth" v:"required;date"`
	Gender string `json:"gender" v:"enum=male,female"`
	Major []string `json:"major" v:"required;item.enum=Math,Physics,English"`
}

func main() {
	user := User{
		Name:  "test",
		Age:   17,
		Email: "example@gmail.com",
		Addresses: []Address{
			{
				Label: "Home",
			},
		},
		Gender: "mole",
		Major: "Math",
	}

	// Validate the user
	ok, errors := validator.Validate(user)
	if !ok {
		fmt.Println(json.NewEncoder(os.Stdout).Encode(errors))
	}

	// Email validation using function
	if isValid := validator.IsValidEmail(user.Email); isValid {
		fmt.Println("Email is valid")
	}

}

Console Output

{
   "addresses":{
      "0":{
         "city":"This field is required",
         "street":"This field is required"
      }
   },
   "age":"This field must be at least 18",
   "dateOfBirth":"This field is required",
   "gender":"This field must be one of the following values: male,female"
}

Email is valid

Contributing

We welcome contributions to this project! If you have an idea for a new feature or have found a bug, please open an issue on GitHub. If you would like to contribute code, please follow these guidelines:

• Fork the repository and create a new branch for your changes.
• Make your changes, including appropriate tests.
• Submit a pull request for review.