govalidator

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 Go to latest Published: May 19, 2020 License: MIT Imports: 23 Imported by: 0

README

govalidator

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A package of validators and sanitizers for strings, structs and collections. Based on validator.js.

Installation

Make sure that Go is installed on your computer. Type the following command in your terminal:

go get github.com/asaskevich/govalidator

or you can get specified release of the package with gopkg.in:

go get gopkg.in/asaskevich/govalidator.v4

After it the package is ready to use.

Import package in your project

Add following line in your *.go file:

import "github.com/asaskevich/govalidator"

If you are unhappy to use long govalidator, you can do something like this:

import (
  valid "github.com/asaskevich/govalidator"
)
Activate behavior to require all fields have a validation tag by default

SetFieldsRequiredByDefault causes validation to fail when struct fields do not include validations or are not explicitly marked as exempt (using valid:"-" or valid:"email,optional"). A good place to activate this is a package init function or the main() function.

import "github.com/asaskevich/govalidator"

func init() {
  govalidator.SetFieldsRequiredByDefault(true)
}

Here's some code to explain it:

// this struct definition will fail govalidator.ValidateStruct() (and the field values do not matter):
type exampleStruct struct {
  Name  string ``
  Email string `valid:"email"`
}

// this, however, will only fail when Email is empty or an invalid email address:
type exampleStruct2 struct {
  Name  string `valid:"-"`
  Email string `valid:"email"`
}

// lastly, this will only fail when Email is an invalid email address but not when it's empty:
type exampleStruct2 struct {
  Name  string `valid:"-"`
  Email string `valid:"email,optional"`
}
Recent breaking changes (see #123)
Custom validator function signature

A context was added as the second parameter, for structs this is the object being validated – this makes dependent validation possible.

import "github.com/asaskevich/govalidator"

// old signature
func(i interface{}) bool

// new signature
func(i interface{}, o interface{}) bool
Adding a custom validator

This was changed to prevent data races when accessing custom validators.

import "github.com/asaskevich/govalidator"

// before
govalidator.CustomTypeTagMap["customByteArrayValidator"] = CustomTypeValidator(func(i interface{}, o interface{}) bool {
  // ...
})

// after
govalidator.CustomTypeTagMap.Set("customByteArrayValidator", CustomTypeValidator(func(i interface{}, o interface{}) bool {
  // ...
}))
List of functions:
func Abs(value float64) float64
func BlackList(str, chars string) string
func ByteLength(str string, params ...string) bool
func CamelCaseToUnderscore(str string) string
func Contains(str, substring string) bool
func Count(array []interface{}, iterator ConditionIterator) int
func Each(array []interface{}, iterator Iterator)
func ErrorByField(e error, field string) string
func ErrorsByField(e error) map[string]string
func Filter(array []interface{}, iterator ConditionIterator) []interface{}
func Find(array []interface{}, iterator ConditionIterator) interface{}
func GetLine(s string, index int) (string, error)
func GetLines(s string) []string
func InRange(value, left, right float64) bool
func IsASCII(str string) bool
func IsAlpha(str string) bool
func IsAlphanumeric(str string) bool
func IsBase64(str string) bool
func IsByteLength(str string, min, max int) bool
func IsCIDR(str string) bool
func IsCreditCard(str string) bool
func IsDNSName(str string) bool
func IsDataURI(str string) bool
func IsDialString(str string) bool
func IsDivisibleBy(str, num string) bool
func IsEmail(str string) bool
func IsFilePath(str string) (bool, int)
func IsFloat(str string) bool
func IsFullWidth(str string) bool
func IsHalfWidth(str string) bool
func IsHexadecimal(str string) bool
func IsHexcolor(str string) bool
func IsHost(str string) bool
func IsIP(str string) bool
func IsIPv4(str string) bool
func IsIPv6(str string) bool
func IsISBN(str string, version int) bool
func IsISBN10(str string) bool
func IsISBN13(str string) bool
func IsISO3166Alpha2(str string) bool
func IsISO3166Alpha3(str string) bool
func IsISO693Alpha2(str string) bool
func IsISO693Alpha3b(str string) bool
func IsISO4217(str string) bool
func IsIn(str string, params ...string) bool
func IsInt(str string) bool
func IsJSON(str string) bool
func IsLatitude(str string) bool
func IsLongitude(str string) bool
func IsLowerCase(str string) bool
func IsMAC(str string) bool
func IsMongoID(str string) bool
func IsMultibyte(str string) bool
func IsNatural(value float64) bool
func IsNegative(value float64) bool
func IsNonNegative(value float64) bool
func IsNonPositive(value float64) bool
func IsNull(str string) bool
func IsNumeric(str string) bool
func IsPort(str string) bool
func IsPositive(value float64) bool
func IsPrintableASCII(str string) bool
func IsRFC3339(str string) bool
func IsRFC3339WithoutZone(str string) bool
func IsRGBcolor(str string) bool
func IsRequestURI(rawurl string) bool
func IsRequestURL(rawurl string) bool
func IsSSN(str string) bool
func IsSemver(str string) bool
func IsTime(str string, format string) bool
func IsURL(str string) bool
func IsUTFDigit(str string) bool
func IsUTFLetter(str string) bool
func IsUTFLetterNumeric(str string) bool
func IsUTFNumeric(str string) bool
func IsUUID(str string) bool
func IsUUIDv3(str string) bool
func IsUUIDv4(str string) bool
func IsUUIDv5(str string) bool
func IsUpperCase(str string) bool
func IsVariableWidth(str string) bool
func IsWhole(value float64) bool
func LeftTrim(str, chars string) string
func Map(array []interface{}, iterator ResultIterator) []interface{}
func Matches(str, pattern string) bool
func NormalizeEmail(str string) (string, error)
func PadBoth(str string, padStr string, padLen int) string
func PadLeft(str string, padStr string, padLen int) string
func PadRight(str string, padStr string, padLen int) string
func Range(str string, params ...string) bool
func RemoveTags(s string) string
func ReplacePattern(str, pattern, replace string) string
func Reverse(s string) string
func RightTrim(str, chars string) string
func RuneLength(str string, params ...string) bool
func SafeFileName(str string) string
func SetFieldsRequiredByDefault(value bool)
func Sign(value float64) float64
func StringLength(str string, params ...string) bool
func StringMatches(s string, params ...string) bool
func StripLow(str string, keepNewLines bool) string
func ToBoolean(str string) (bool, error)
func ToFloat(str string) (float64, error)
func ToInt(str string) (int64, error)
func ToJSON(obj interface{}) (string, error)
func ToString(obj interface{}) string
func Trim(str, chars string) string
func Truncate(str string, length int, ending string) string
func UnderscoreToCamelCase(s string) string
func ValidateStruct(s interface{}) (bool, error)
func WhiteList(str, chars string) string
type ConditionIterator
type CustomTypeValidator
type Error
func (e Error) Error() string
type Errors
func (es Errors) Error() string
func (es Errors) Errors() []error
type ISO3166Entry
type Iterator
type ParamValidator
type ResultIterator
type UnsupportedTypeError
func (e *UnsupportedTypeError) Error() string
type Validator
Examples
IsURL
println(govalidator.IsURL(`http://user@pass:domain.com/path/page`))
ToString
type User struct {
	FirstName string
	LastName string
}

str := govalidator.ToString(&User{"John", "Juan"})
println(str)
Each, Map, Filter, Count for slices

Each iterates over the slice/array and calls Iterator for every item

data := []interface{}{1, 2, 3, 4, 5}
var fn govalidator.Iterator = func(value interface{}, index int) {
	println(value.(int))
}
govalidator.Each(data, fn)

data := []interface{}{1, 2, 3, 4, 5}
var fn govalidator.ResultIterator = func(value interface{}, index int) interface{} {
	return value.(int) * 3
}
_ = govalidator.Map(data, fn) // result = []interface{}{1, 6, 9, 12, 15}

data := []interface{}{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
var fn govalidator.ConditionIterator = func(value interface{}, index int) bool {
	return value.(int)%2 == 0
}
_ = govalidator.Filter(data, fn) // result = []interface{}{2, 4, 6, 8, 10}
_ = govalidator.Count(data, fn) // result = 5
ValidateStruct #2

If you want to validate structs, you can use tag valid for any field in your structure. All validators used with this field in one tag are separated by comma. If you want to skip validation, place - in your tag. If you need a validator that is not on the list below, you can add it like this:

govalidator.TagMap["duck"] = govalidator.Validator(func(str string) bool {
	return str == "duck"
})

For completely custom validators (interface-based), see below.

Here is a list of available validators for struct fields (validator - used function):

"email":              IsEmail,
"url":                IsURL,
"dialstring":         IsDialString,
"requrl":             IsRequestURL,
"requri":             IsRequestURI,
"alpha":              IsAlpha,
"utfletter":          IsUTFLetter,
"alphanum":           IsAlphanumeric,
"utfletternum":       IsUTFLetterNumeric,
"numeric":            IsNumeric,
"utfnumeric":         IsUTFNumeric,
"utfdigit":           IsUTFDigit,
"hexadecimal":        IsHexadecimal,
"hexcolor":           IsHexcolor,
"rgbcolor":           IsRGBcolor,
"lowercase":          IsLowerCase,
"uppercase":          IsUpperCase,
"int":                IsInt,
"float":              IsFloat,
"null":               IsNull,
"uuid":               IsUUID,
"uuidv3":             IsUUIDv3,
"uuidv4":             IsUUIDv4,
"uuidv5":             IsUUIDv5,
"creditcard":         IsCreditCard,
"isbn10":             IsISBN10,
"isbn13":             IsISBN13,
"json":               IsJSON,
"multibyte":          IsMultibyte,
"ascii":              IsASCII,
"printableascii":     IsPrintableASCII,
"fullwidth":          IsFullWidth,
"halfwidth":          IsHalfWidth,
"variablewidth":      IsVariableWidth,
"base64":             IsBase64,
"datauri":            IsDataURI,
"ip":                 IsIP,
"port":               IsPort,
"ipv4":               IsIPv4,
"ipv6":               IsIPv6,
"dns":                IsDNSName,
"host":               IsHost,
"mac":                IsMAC,
"latitude":           IsLatitude,
"longitude":          IsLongitude,
"ssn":                IsSSN,
"semver":             IsSemver,
"rfc3339":            IsRFC3339,
"rfc3339WithoutZone": IsRFC3339WithoutZone,
"ISO3166Alpha2":      IsISO3166Alpha2,
"ISO3166Alpha3":      IsISO3166Alpha3,

Validators with parameters

"range(min|max)": Range,
"length(min|max)": ByteLength,
"runelength(min|max)": RuneLength,
"matches(pattern)": StringMatches,
"in(string1|string2|...|stringN)": IsIn,

And here is small example of usage:

type Post struct {
	Title    string `valid:"alphanum,required"`
	Message  string `valid:"duck,ascii"`
	AuthorIP string `valid:"ipv4"`
	Date     string `valid:"-"`
}
post := &Post{
	Title:   "My Example Post",
	Message: "duck",
	AuthorIP: "123.234.54.3",
}

// Add your own struct validation tags
govalidator.TagMap["duck"] = govalidator.Validator(func(str string) bool {
	return str == "duck"
})

result, err := govalidator.ValidateStruct(post)
if err != nil {
	println("error: " + err.Error())
}
println(result)
WhiteList
// Remove all characters from string ignoring characters between "a" and "z"
println(govalidator.WhiteList("a3a43a5a4a3a2a23a4a5a4a3a4", "a-z") == "aaaaaaaaaaaa")
Custom validation functions

Custom validation using your own domain specific validators is also available - here's an example of how to use it:

import "github.com/asaskevich/govalidator"

type CustomByteArray [6]byte // custom types are supported and can be validated

type StructWithCustomByteArray struct {
  ID              CustomByteArray `valid:"customByteArrayValidator,customMinLengthValidator"` // multiple custom validators are possible as well and will be evaluated in sequence
  Email           string          `valid:"email"`
  CustomMinLength int             `valid:"-"`
}

govalidator.CustomTypeTagMap.Set("customByteArrayValidator", CustomTypeValidator(func(i interface{}, context interface{}) bool {
  switch v := context.(type) { // you can type switch on the context interface being validated
  case StructWithCustomByteArray:
    // you can check and validate against some other field in the context,
    // return early or not validate against the context at all – your choice
  case SomeOtherType:
    // ...
  default:
    // expecting some other type? Throw/panic here or continue
  }

  switch v := i.(type) { // type switch on the struct field being validated
  case CustomByteArray:
    for _, e := range v { // this validator checks that the byte array is not empty, i.e. not all zeroes
      if e != 0 {
        return true
      }
    }
  }
  return false
}))
govalidator.CustomTypeTagMap.Set("customMinLengthValidator", CustomTypeValidator(func(i interface{}, context interface{}) bool {
  switch v := context.(type) { // this validates a field against the value in another field, i.e. dependent validation
  case StructWithCustomByteArray:
    return len(v.ID) >= v.CustomMinLength
  }
  return false
}))
Custom error messages

Custom error messages are supported via annotations by adding the ~ separator - here's an example of how to use it:

type Ticket struct {
  Id        int64     `json:"id"`
  FirstName string    `json:"firstname" valid:"required~First name is blank"`
}
Notes

Documentation is available here: godoc.org. Full information about code coverage is also available here: govalidator on gocover.io.

Support

If you do have a contribution to the package, feel free to create a Pull Request or an Issue.

What to contribute

If you don't know what to do, there are some features and functions that need to be done

  • Refactor code
  • Edit docs and README: spellcheck, grammar and typo check
  • Create actual list of contributors and projects that currently using this package
  • Resolve issues and bugs
  • Update actual list of functions
  • Update list of validators that available for ValidateStruct and add new
  • Implement new validators: IsFQDN, IsIMEI, IsPostalCode, IsISIN, IsISRC etc
  • Implement validation by maps
  • Implement fuzzing testing
  • Implement some struct/map/array utilities
  • Implement map/array validation
  • Implement benchmarking
  • Implement batch of examples
  • Look at forks for new features and fixes
Advice

Feel free to create what you want, but keep in mind when you implement new features:

  • Code must be clear and readable, names of variables/constants clearly describes what they are doing
  • Public functions must be documented and described in source file and added to README.md to the list of available functions
  • There are must be unit-tests for any new functions and improvements

Credits

Contributors

This project exists thanks to all the people who contribute. [Contribute].

Special thanks to contributors

Backers

Thank you to all our backers! 🙏 [Become a backer]

Sponsors

Support this project by becoming a sponsor. Your logo will show up here with a link to your website. [Become a sponsor]

Documentation

Overview

Package govalidator is package of validators and sanitizers for strings, structs and collections.

Index

Examples

Constants

View Source 
const (
	Email          string = "" /* 1208-byte string literal not displayed */
	CreditCard     string = "" /* 151-byte string literal not displayed */
	ISBN10         string = "^(?:[0-9]{9}X|[0-9]{10})$"
	ISBN13         string = "^(?:[0-9]{13})$"
	UUID3          string = "^[0-9a-f]{8}-[0-9a-f]{4}-3[0-9a-f]{3}-[0-9a-f]{4}-[0-9a-f]{12}$"
	UUID4          string = "^[0-9a-f]{8}-[0-9a-f]{4}-4[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$"
	UUID5          string = "^[0-9a-f]{8}-[0-9a-f]{4}-5[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$"
	UUID           string = "^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$"
	Alpha          string = "^[a-zA-Z]+$"
	Alphanumeric   string = "^[a-zA-Z0-9]+$"
	Numeric        string = "^[0-9]+$"
	Int            string = "^(?:[-+]?(?:0|[1-9][0-9]*))$"
	Float          string = "^(?:[-+]?(?:[0-9]+))?(?:\\.[0-9]*)?(?:[eE][\\+\\-]?(?:[0-9]+))?$"
	Hexadecimal    string = "^[0-9a-fA-F]+$"
	Hexcolor       string = "^#?([0-9a-fA-F]{3}|[0-9a-fA-F]{6})$"
	RGBcolor       string = "" /* 157-byte string literal not displayed */
	ASCII          string = "^[\x00-\x7F]+$"
	Multibyte      string = "[^\x00-\x7F]"
	FullWidth      string = "[^\u0020-\u007E\uFF61-\uFF9F\uFFA0-\uFFDC\uFFE8-\uFFEE0-9a-zA-Z]"
	HalfWidth      string = "[\u0020-\u007E\uFF61-\uFF9F\uFFA0-\uFFDC\uFFE8-\uFFEE0-9a-zA-Z]"
	Base64         string = "^(?:[A-Za-z0-9+\\/]{4})*(?:[A-Za-z0-9+\\/]{2}==|[A-Za-z0-9+\\/]{3}=|[A-Za-z0-9+\\/]{4})$"
	PrintableASCII string = "^[\x20-\x7E]+$"
	DataURI        string = "^data:.+\\/(.+);base64$"
	Latitude       string = "^[-+]?([1-8]?\\d(\\.\\d+)?|90(\\.0+)?)$"
	Longitude      string = "^[-+]?(180(\\.0+)?|((1[0-7]\\d)|([1-9]?\\d))(\\.\\d+)?)$"
	DNSName        string = `^([a-zA-Z0-9_]{1}[a-zA-Z0-9_-]{0,62}){1}(\.[a-zA-Z0-9_]{1}[a-zA-Z0-9_-]{0,62})*[\._]?$`
	IP             string = `` /* 659-byte string literal not displayed */
	URLSchema      string = `((ftp|tcp|udp|wss?|https?):\/\/)`
	URLUsername    string = `(\S+(:\S*)?@)`
	URLPath        string = `((\/|\?|#)[^\s]*)`
	URLPort        string = `(:(\d{1,5}))`
	URLIP          string = `([1-9]\d?|1\d\d|2[01]\d|22[0-3])(\.(1?\d{1,2}|2[0-4]\d|25[0-5])){2}(?:\.([0-9]\d?|1\d\d|2[0-4]\d|25[0-4]))`
	URLSubdomain   string = `((www\.)|([a-zA-Z0-9]([-\.][-\._a-zA-Z0-9]+)*))`
	URL            string = `^` + URLSchema + `?` + URLUsername + `?` + `((` + URLIP + `|(\[` + IP + `\])|(([a-zA-Z0-9]([a-zA-Z0-9-_]+)?[a-zA-Z0-9]([-\.][a-zA-Z0-9]+)*)|(` + URLSubdomain + `?))?(([a-zA-Z\x{00a1}-\x{ffff}0-9]+-?-?)*[a-zA-Z\x{00a1}-\x{ffff}0-9]+)(?:\.([a-zA-Z\x{00a1}-\x{ffff}]{1,}))?))\.?` + URLPort + `?` + URLPath + `?$`
	SSN            string = `^\d{3}[- ]?\d{2}[- ]?\d{4}$`
	WinPath        string = `^[a-zA-Z]:\\(?:[^\\/:*?"<>|\r\n]+\\)*[^\\/:*?"<>|\r\n]*$`
	UnixPath       string = `^(/[^/\x00]*)+/?$`
	Semver         string = "" /* 183-byte string literal not displayed */

)

Basic regular expressions for validating strings

View Source 
const (
	// Unknown is unresolved OS type
	Unknown = iota
	// Win is Windows type
	Win
	// Unix is *nix OS types
	Unix
)

Used by IsFilePath func

View Source 
const RF3339WithoutZone = "2006-01-02T15:04:05"

Variables

View Source 
var CustomTypeTagMap = &customTypeTagMap{validators: make(map[string]CustomTypeValidator)}

CustomTypeTagMap is a map of functions that can be used as tags for ValidateStruct function. Use this to validate compound or custom types that need to be handled as a whole, e.g. `type UUID [16]byte` (this would be handled as an array of bytes).

View Source 
var Escape = html.EscapeString

Escape replace <, >, & and " with HTML entities.

View Source 
var ISO3166List = []ISO3166Entry{}/* 249 elements not displayed */

ISO3166List based on https://www.iso.org/obp/ui/#search/code/ Code Type "Officially Assigned Codes"

View Source 
var ISO4217List = []string{}/* 178 elements not displayed */

ISO4217List is the list of ISO currency codes

View Source 
var ISO693List = []ISO693Entry{}/* 184 elements not displayed */

ISO693List based on http://data.okfn.org/data/core/language-codes/r/language-codes-3b2.json

View Source 
var ParamTagMap = map[string]ParamValidator{
	"length":       ByteLength,
	"range":        Range,
	"runelength":   RuneLength,
	"stringlength": StringLength,
	"matches":      StringMatches,
	"in":           isInRaw,
	"rsapub":       IsRsaPub,
}

ParamTagMap is a map of functions accept variants parameters

View Source 
var ParamTagRegexMap = map[string]*regexp.Regexp{
	"range":        regexp.MustCompile("^range\\((\\d+)\\|(\\d+)\\)$"),
	"length":       regexp.MustCompile("^length\\((\\d+)\\|(\\d+)\\)$"),
	"runelength":   regexp.MustCompile("^runelength\\((\\d+)\\|(\\d+)\\)$"),
	"stringlength": regexp.MustCompile("^stringlength\\((\\d+)\\|(\\d+)\\)$"),
	"in":           regexp.MustCompile(`^in\((.*)\)`),
	"matches":      regexp.MustCompile(`^matches\((.+)\)$`),
	"rsapub":       regexp.MustCompile("^rsapub\\((\\d+)\\)$"),
}

ParamTagRegexMap maps param tags to their respective regexes.

View Source 
var TagMap = map[string]Validator{
	"email":              IsEmail,
	"url":                IsURL,
	"dialstring":         IsDialString,
	"requrl":             IsRequestURL,
	"requri":             IsRequestURI,
	"alpha":              IsAlpha,
	"utfletter":          IsUTFLetter,
	"alphanum":           IsAlphanumeric,
	"utfletternum":       IsUTFLetterNumeric,
	"numeric":            IsNumeric,
	"utfnumeric":         IsUTFNumeric,
	"utfdigit":           IsUTFDigit,
	"hexadecimal":        IsHexadecimal,
	"hexcolor":           IsHexcolor,
	"rgbcolor":           IsRGBcolor,
	"lowercase":          IsLowerCase,
	"uppercase":          IsUpperCase,
	"int":                IsInt,
	"float":              IsFloat,
	"null":               IsNull,
	"uuid":               IsUUID,
	"uuidv3":             IsUUIDv3,
	"uuidv4":             IsUUIDv4,
	"uuidv5":             IsUUIDv5,
	"creditcard":         IsCreditCard,
	"isbn10":             IsISBN10,
	"isbn13":             IsISBN13,
	"json":               IsJSON,
	"multibyte":          IsMultibyte,
	"ascii":              IsASCII,
	"printableascii":     IsPrintableASCII,
	"fullwidth":          IsFullWidth,
	"halfwidth":          IsHalfWidth,
	"variablewidth":      IsVariableWidth,
	"base64":             IsBase64,
	"datauri":            IsDataURI,
	"ip":                 IsIP,
	"port":               IsPort,
	"ipv4":               IsIPv4,
	"ipv6":               IsIPv6,
	"dns":                IsDNSName,
	"host":               IsHost,
	"mac":                IsMAC,
	"latitude":           IsLatitude,
	"longitude":          IsLongitude,
	"ssn":                IsSSN,
	"semver":             IsSemver,
	"rfc3339":            IsRFC3339,
	"rfc3339WithoutZone": IsRFC3339WithoutZone,
	"ISO3166Alpha2":      IsISO3166Alpha2,
	"ISO3166Alpha3":      IsISO3166Alpha3,
	"ISO4217":            IsISO4217,
}

TagMap is a map of functions, that can be used as tags for ValidateStruct function.

Functions

func Abs 

func Abs(value float64) float64

Abs returns absolute value of number

func BlackList 

func BlackList(str, chars string) string

BlackList remove characters that appear in the blacklist.

func ByteLength 

func ByteLength(str string, params ...string) bool

ByteLength check string's length

func CamelCaseToUnderscore 

func CamelCaseToUnderscore(str string) string

CamelCaseToUnderscore converts from camel case form to underscore separated form. Ex.: MyFunc => my_func

func Contains 

func Contains(str, substring string) bool

Contains check if the string contains the substring.

func Count 

func Count(array []interface{}, iterator ConditionIterator) int

Count iterates over the slice and apply ConditionIterator to every item. Returns count of items that meets ConditionIterator.

Example 
data := []interface{}{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
var fn ConditionIterator = func(value interface{}, index int) bool {
	return value.(int)%2 == 0
}
_ = Count(data, fn) // result = 5

Output:

func Each 

func Each(array []interface{}, iterator Iterator)

Each iterates over the slice and apply Iterator to every item

Example 
data := []interface{}{1, 2, 3, 4, 5}
var fn Iterator = func(value interface{}, index int) {
	println(value.(int))
}
Each(data, fn)

Output:

func ErrorByField 

func ErrorByField(e error, field string) string

ErrorByField returns error for specified field of the struct validated by ValidateStruct or empty string if there are no errors or this field doesn't exists or doesn't have any errors.

func ErrorsByField 

func ErrorsByField(e error) map[string]string

ErrorsByField returns map of errors of the struct validated by ValidateStruct or empty map if there are no errors.

func Filter 

func Filter(array []interface{}, iterator ConditionIterator) []interface{}

Filter iterates over the slice and apply ConditionIterator to every item. Returns new slice.

Example 
data := []interface{}{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
var fn ConditionIterator = func(value interface{}, index int) bool {
	return value.(int)%2 == 0
}
_ = Filter(data, fn) // result = []interface{}{2, 4, 6, 8, 10}

Output:

func Find 

func Find(array []interface{}, iterator ConditionIterator) interface{}

Find iterates over the slice and apply ConditionIterator to every item. Returns first item that meet ConditionIterator or nil otherwise.

func GetLine 

func GetLine(s string, index int) (string, error)

GetLine return specified line of multiline string

func GetLines 

func GetLines(s string) []string

GetLines split string by "\n" and return array of lines

func HasLowerCase 

func HasLowerCase(str string) bool

HasLowerCase check if the string contains at least 1 lowercase. Empty string is valid.

func HasUpperCase 

func HasUpperCase(str string) bool

HasUpperCase check if the string contians as least 1 uppercase. Empty string is valid.

func InRange 

func InRange(value interface{}, left interface{}, right interface{}) bool

InRange returns true if value lies between left and right border, generic type to handle int, float32 or float64, all types must the same type

func InRangeFloat32 

func InRangeFloat32(value, left, right float32) bool

InRange returns true if value lies between left and right border

func InRangeFloat64 

func InRangeFloat64(value, left, right float64) bool

InRange returns true if value lies between left and right border

func InRangeInt 

func InRangeInt(value, left, right interface{}) bool

InRange returns true if value lies between left and right border

func IsASCII 

func IsASCII(str string) bool

IsASCII check if the string contains ASCII chars only. Empty string is valid.

func IsAlpha 

func IsAlpha(str string) bool

IsAlpha check if the string contains only letters (a-zA-Z). Empty string is valid.

func IsAlphanumeric 

func IsAlphanumeric(str string) bool

IsAlphanumeric check if the string contains only letters and numbers. Empty string is valid.

func IsBase64 

func IsBase64(str string) bool

IsBase64 check if a string is base64 encoded.

func IsByteLength 

func IsByteLength(str string, min, max int) bool

IsByteLength check if the string's length (in bytes) falls in a range.

func IsCIDR 

func IsCIDR(str string) bool

IsCIDR check if the string is an valid CIDR notiation (IPV4 & IPV6)

func IsCreditCard 

func IsCreditCard(str string) bool

IsCreditCard check if the string is a credit card.

func IsDNSName 

func IsDNSName(str string) bool

IsDNSName will validate the given string as a DNS name

func IsDataURI 

func IsDataURI(str string) bool

IsDataURI checks if a string is base64 encoded data URI such as an image

func IsDialString 

func IsDialString(str string) bool

IsDialString validates the given string for usage with the various Dial() functions

func IsDivisibleBy 

func IsDivisibleBy(str, num string) bool

IsDivisibleBy check if the string is a number that's divisible by another. If second argument is not valid integer or zero, it's return false. Otherwise, if first argument is not valid integer or zero, it's return true (Invalid string converts to zero).

Example

This small example illustrate how to work with IsDivisibleBy function. 

println("1024 is divisible by 64: ", IsDivisibleBy("1024", "64"))

Output:

func IsEmail 

func IsEmail(str string) bool

IsEmail check if the string is an email.

func IsExistingEmail 

func IsExistingEmail(email string) bool

IsExistingEmail check if the string is an email of existing domain

func IsFilePath 

func IsFilePath(str string) (bool, int)

IsFilePath check is a string is Win or Unix file path and returns it's type.

func IsFloat 

func IsFloat(str string) bool

IsFloat check if the string is a float.

func IsFullWidth 

func IsFullWidth(str string) bool

IsFullWidth check if the string contains any full-width chars. Empty string is valid.

func IsHalfWidth 

func IsHalfWidth(str string) bool

IsHalfWidth check if the string contains any half-width chars. Empty string is valid.

func IsHash 

func IsHash(str string, algorithm string) bool

IsHash checks if a string is a hash of type algorithm. Algorithm is one of ['md4', 'md5', 'sha1', 'sha256', 'sha384', 'sha512', 'ripemd128', 'ripemd160', 'tiger128', 'tiger160', 'tiger192', 'crc32', 'crc32b']

func IsHexadecimal 

func IsHexadecimal(str string) bool

IsHexadecimal check if the string is a hexadecimal number.

func IsHexcolor 

func IsHexcolor(str string) bool

IsHexcolor check if the string is a hexadecimal color.

func IsHost 

func IsHost(str string) bool

IsHost checks if the string is a valid IP (both v4 and v6) or a valid DNS name

func IsIP 

func IsIP(str string) bool

IsIP checks if a string is either IP version 4 or 6.

func IsIPv4 

func IsIPv4(str string) bool

IsIPv4 check if the string is an IP version 4.

func IsIPv6 

func IsIPv6(str string) bool

IsIPv6 check if the string is an IP version 6.

func IsISBN 

func IsISBN(str string, version int) bool

IsISBN check if the string is an ISBN (version 10 or 13). If version value is not equal to 10 or 13, it will be check both variants.

func IsISBN10 

func IsISBN10(str string) bool

IsISBN10 check if the string is an ISBN version 10.

func IsISBN13 

func IsISBN13(str string) bool

IsISBN13 check if the string is an ISBN version 13.

func IsISO3166Alpha2 

func IsISO3166Alpha2(str string) bool

IsISO3166Alpha2 checks if a string is valid two-letter country code

func IsISO3166Alpha3 

func IsISO3166Alpha3(str string) bool

IsISO3166Alpha3 checks if a string is valid three-letter country code

func IsISO4217 

func IsISO4217(str string) bool

IsISO4217 check if string is valid ISO currency code

func IsISO693Alpha2 

func IsISO693Alpha2(str string) bool

IsISO693Alpha2 checks if a string is valid two-letter language code

func IsISO693Alpha3b 

func IsISO693Alpha3b(str string) bool

IsISO693Alpha3b checks if a string is valid three-letter language code

func IsIn 

func IsIn(str string, params ...string) bool

IsIn check if string str is a member of the set of strings params

func IsInt 

func IsInt(str string) bool

IsInt check if the string is an integer. Empty string is valid.

func IsJSON 

func IsJSON(str string) bool

IsJSON check if the string is valid JSON (note: uses json.Unmarshal).

func IsLatitude 

func IsLatitude(str string) bool

IsLatitude check if a string is valid latitude.

func IsLongitude 

func IsLongitude(str string) bool

IsLongitude check if a string is valid longitude.

func IsLowerCase 

func IsLowerCase(str string) bool

IsLowerCase check if the string is lowercase. Empty string is valid.

func IsMAC 

func IsMAC(str string) bool

IsMAC check if a string is valid MAC address. Possible MAC formats: 01:23:45:67:89:ab 01:23:45:67:89:ab:cd:ef 01-23-45-67-89-ab 01-23-45-67-89-ab-cd-ef 0123.4567.89ab 0123.4567.89ab.cdef

func IsMongoID 

func IsMongoID(str string) bool

IsMongoID check if the string is a valid hex-encoded representation of a MongoDB ObjectId.

func IsMultibyte 

func IsMultibyte(str string) bool

IsMultibyte check if the string contains one or more multibyte chars. Empty string is valid.

func IsNatural 

func IsNatural(value float64) bool

IsNatural returns true if value is natural number (positive and whole)

func IsNegative 

func IsNegative(value float64) bool

IsNegative returns true if value < 0

func IsNonNegative 

func IsNonNegative(value float64) bool

IsNonNegative returns true if value >= 0

func IsNonPositive 

func IsNonPositive(value float64) bool

IsNonPositive returns true if value <= 0

func IsNull 

func IsNull(str string) bool

IsNull check if the string is null.

func IsNumeric 

func IsNumeric(str string) bool

IsNumeric check if the string contains only numbers. Empty string is valid.

func IsPort 

func IsPort(str string) bool

IsPort checks if a string represents a valid port

func IsPositive 

func IsPositive(value float64) bool

IsPositive returns true if value > 0

func IsPrintableASCII 

func IsPrintableASCII(str string) bool

IsPrintableASCII check if the string contains printable ASCII chars only. Empty string is valid.

func IsRFC3339 

func IsRFC3339(str string) bool

IsRFC3339 check if string is valid timestamp value according to RFC3339

func IsRFC3339WithoutZone 

func IsRFC3339WithoutZone(str string) bool

IsRFC3339WithoutZone check if string is valid timestamp value according to RFC3339 which excludes the timezone.

func IsRGBcolor 

func IsRGBcolor(str string) bool

IsRGBcolor check if the string is a valid RGB color in form rgb(RRR, GGG, BBB).

func IsRequestURI 

func IsRequestURI(rawurl string) bool

IsRequestURI check if the string rawurl, assuming it was received in an HTTP request, is an absolute URI or an absolute path.

func IsRequestURL 

func IsRequestURL(rawurl string) bool

IsRequestURL check if the string rawurl, assuming it was received in an HTTP request, is a valid URL confirm to RFC 3986

func IsRsaPub 

func IsRsaPub(str string, params ...string) bool

IsRsaPub check whether string is valid RSA key Alias for IsRsaPublicKey

func IsRsaPublicKey 

func IsRsaPublicKey(str string, keylen int) bool

IsRsaPublicKey check if a string is valid public key with provided length

func IsSSN 

func IsSSN(str string) bool

IsSSN will validate the given string as a U.S. Social Security Number

func IsSemver 

func IsSemver(str string) bool

IsSemver check if string is valid semantic version

func IsTime 

func IsTime(str string, format string) bool

IsTime check if string is valid according to given format

func IsURL 

func IsURL(str string) bool

IsURL check if the string is an URL.

func IsUTFDigit 

func IsUTFDigit(str string) bool

IsUTFDigit check if the string contains only unicode radix-10 decimal digits. Empty string is valid.

func IsUTFLetter 

func IsUTFLetter(str string) bool

IsUTFLetter check if the string contains only unicode letter characters. Similar to IsAlpha but for all languages. Empty string is valid.

func IsUTFLetterNumeric 

func IsUTFLetterNumeric(str string) bool

IsUTFLetterNumeric check if the string contains only unicode letters and numbers. Empty string is valid.

func IsUTFNumeric 

func IsUTFNumeric(str string) bool

IsUTFNumeric check if the string contains only unicode numbers of any kind. Numbers can be 0-9 but also Fractions ¾,Roman Ⅸ and Hangzhou 〩. Empty string is valid.

func IsUUID 

func IsUUID(str string) bool

IsUUID check if the string is a UUID (version 3, 4 or 5).

func IsUUIDv3 

func IsUUIDv3(str string) bool

IsUUIDv3 check if the string is a UUID version 3.

func IsUUIDv4 

func IsUUIDv4(str string) bool

IsUUIDv4 check if the string is a UUID version 4.

func IsUUIDv5 

func IsUUIDv5(str string) bool

IsUUIDv5 check if the string is a UUID version 5.

func IsUpperCase 

func IsUpperCase(str string) bool

IsUpperCase check if the string is uppercase. Empty string is valid.

func IsVariableWidth 

func IsVariableWidth(str string) bool

IsVariableWidth check if the string contains a mixture of full and half-width chars. Empty string is valid.

func IsWhole 

func IsWhole(value float64) bool

IsWhole returns true if value is whole number

func LeftTrim 

func LeftTrim(str, chars string) string

LeftTrim trim characters from the left-side of the input. If second argument is empty, it's will be remove leading spaces.

func Map 

func Map(array []interface{}, iterator ResultIterator) []interface{}

Map iterates over the slice and apply ResultIterator to every item. Returns new slice as a result.

Example 
data := []interface{}{1, 2, 3, 4, 5}
var fn ResultIterator = func(value interface{}, index int) interface{} {
	return value.(int) * 3
}
_ = Map(data, fn) // result = []interface{}{1, 6, 9, 12, 15}

Output:

func Matches 

func Matches(str, pattern string) bool

Matches check if string matches the pattern (pattern is regular expression) In case of error return false

func NormalizeEmail 

func NormalizeEmail(str string) (string, error)

NormalizeEmail canonicalize an email address. The local part of the email address is lowercased for all domains; the hostname is always lowercased and the local part of the email address is always lowercased for hosts that are known to be case-insensitive (currently only GMail). Normalization follows special rules for known providers: currently, GMail addresses have dots removed in the local part and are stripped of tags (e.g. some.one+tag@gmail.com becomes someone@gmail.com) and all @googlemail.com addresses are normalized to @gmail.com.

func PadBoth 

func PadBoth(str string, padStr string, padLen int) string

PadBoth pad sides of string if size of string is less then indicated pad length

func PadLeft 

func PadLeft(str string, padStr string, padLen int) string

PadLeft pad left side of string if size of string is less then indicated pad length

func PadRight 

func PadRight(str string, padStr string, padLen int) string

PadRight pad right side of string if size of string is less then indicated pad length

func Range 

func Range(str string, params ...string) bool

Range check string's length

func RemoveTags 

func RemoveTags(s string) string

RemoveTags remove all tags from HTML string

func ReplacePattern 

func ReplacePattern(str, pattern, replace string) string

ReplacePattern replace regular expression pattern in string

Example

This small example illustrate how to work with ReplacePattern function. 

// Replace in "http123123ftp://git534543hub.comio" following (pattern "(ftp|io|[0-9]+)"):
// - Sequence "ftp".
// - Sequence "io".
// - Sequence of digits.
// with empty string.
println(ReplacePattern("http123123ftp://git534543hub.comio", "(ftp|io|[0-9]+)", "") == "http://github.com")

Output:

func Reverse 

func Reverse(s string) string

Reverse return reversed string

func RightTrim 

func RightTrim(str, chars string) string

RightTrim trim characters from the right-side of the input. If second argument is empty, it's will be remove spaces.

func RuneLength 

func RuneLength(str string, params ...string) bool

RuneLength check string's length Alias for StringLength

func SafeFileName 

func SafeFileName(str string) string

SafeFileName return safe string that can be used in file names

func SetFieldsRequiredByDefault 

func SetFieldsRequiredByDefault(value bool)

SetFieldsRequiredByDefault causes validation to fail when struct fields do not include validations or are not explicitly marked as exempt (using `valid:"-"` or `valid:"email,optional"`). This struct definition will fail govalidator.ValidateStruct() (and the field values do not matter): 

type exampleStruct struct {
    Name  string ``
    Email string `valid:"email"`

This, however, will only fail when Email is empty or an invalid email address: 

type exampleStruct2 struct {
    Name  string `valid:"-"`
    Email string `valid:"email"`

Lastly, this will only fail when Email is an invalid email address but not when it's empty: 

type exampleStruct2 struct {
    Name  string `valid:"-"`
    Email string `valid:"email,optional"`

func Sign 

func Sign(value float64) float64

Sign returns signum of number: 1 in case of value > 0, -1 in case of value < 0, 0 otherwise

func StringLength 

func StringLength(str string, params ...string) bool

StringLength check string's length (including multi byte strings)

func StringMatches 

func StringMatches(s string, params ...string) bool

StringMatches checks if a string matches a given pattern.

func StripLow 

func StripLow(str string, keepNewLines bool) string

StripLow remove characters with a numerical value < 32 and 127, mostly control characters. If keep_new_lines is true, newline characters are preserved (\n and \r, hex 0xA and 0xD).

func ToBoolean 

func ToBoolean(str string) (bool, error)

ToBoolean convert the input string to a boolean.

func ToFloat 

func ToFloat(str string) (float64, error)

ToFloat convert the input string to a float, or 0.0 if the input is not a float.

func ToInt 

func ToInt(value interface{}) (res int64, err error)

ToInt convert the input string or any int type to an integer type 64, or 0 if the input is not an integer.

func ToJSON 

func ToJSON(obj interface{}) (string, error)

ToJSON convert the input to a valid JSON string

func ToString 

func ToString(obj interface{}) string

ToString convert the input to a string.

func Trim 

func Trim(str, chars string) string

Trim trim characters from both sides of the input. If second argument is empty, it's will be remove spaces.

Example

This small example illustrate how to work with Trim function. 

// Remove from left and right spaces and "\r", "\n", "\t" characters
println(Trim("   \r\r\ntext\r   \t\n", "") == "text")
// Remove from left and right characters that are between "1" and "8".
// "1-8" is like full list "12345678".
println(Trim("1234567890987654321", "1-8") == "909")

Output:

func Truncate 

func Truncate(str string, length int, ending string) string

Truncate a string to the closest length without breaking words.

func UnderscoreToCamelCase 

func UnderscoreToCamelCase(s string) string

UnderscoreToCamelCase converts from underscore separated form to camel case form. Ex.: my_func => MyFunc

func ValidateStruct 

func ValidateStruct(s interface{}, allowNull bool) (bool, error)

ValidateStruct use tags for fields. result will be equal to `false` if there are any errors.

Example 
type Post struct {
	Title    string `valid:"alphanum,required"`
	Message  string `valid:"duck,ascii"`
	AuthorIP string `valid:"ipv4"`
}
post := &Post{"My Example Post", "duck", "123.234.54.3"}

//Add your own struct validation tags
TagMap["duck"] = Validator(func(str string) bool {
	return str == "duck"
})

result, err := ValidateStruct(post, false)
if err != nil {
	println("error: " + err.Error())
}
println(result)

Output:

func WhiteList 

func WhiteList(str, chars string) string

WhiteList remove characters that do not appear in the whitelist.

Example

This small example illustrate how to work with WhiteList function. 

// Remove all characters from string ignoring characters between "a" and "z"
println(WhiteList("a3a43a5a4a3a2a23a4a5a4a3a4", "a-z") == "aaaaaaaaaaaa")

Output:

Types

type ConditionIterator 

type ConditionIterator func(interface{}, int) bool

ConditionIterator is the function that accepts element of slice/array and its index and returns boolean

type CustomTypeValidator 

type CustomTypeValidator func(i interface{}, o interface{}) bool

CustomTypeValidator is a wrapper for validator functions that returns bool and accepts any type. The second parameter should be the context (in the case of validating a struct: the whole object being validated).

type Error 

type Error struct {
	Name                     string
	Err                      error
	CustomErrorMessageExists bool

	// Validator indicates the name of the validator that failed
	Validator string
}

Error encapsulates a name, an error and whether there's a custom error message or not.

func (Error) Error 

func (e Error) Error() string

type Errors 

type Errors []error

Errors is an array of multiple errors and conforms to the error interface.

func (Errors) Error 

func (es Errors) Error() string

func (Errors) Errors 

func (es Errors) Errors() []error

Errors returns itself.

type ISO3166Entry 

type ISO3166Entry struct {
	EnglishShortName string
	FrenchShortName  string
	Alpha2Code       string
	Alpha3Code       string
	Numeric          string
}

ISO3166Entry stores country codes

type ISO693Entry 

type ISO693Entry struct {
	Alpha3bCode string
	Alpha2Code  string
	English     string
}

ISO693Entry stores ISO language codes

type Iterator 

type Iterator func(interface{}, int)

Iterator is the function that accepts element of slice/array and its index

type ParamValidator 

type ParamValidator func(str string, params ...string) bool

ParamValidator is a wrapper for validator functions that accepts additional parameters.

type ResultIterator 

type ResultIterator func(interface{}, int) interface{}

ResultIterator is the function that accepts element of slice/array and its index and returns any result

type UnsupportedTypeError 

type UnsupportedTypeError struct {
	Type reflect.Type
}

UnsupportedTypeError is a wrapper for reflect.Type

func (*UnsupportedTypeError) Error 

func (e *UnsupportedTypeError) Error() string

Error returns string equivalent for reflect.Type

type Validator 

type Validator func(str string) bool

Validator is a wrapper for a validator function that returns bool and accepts string.

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