README
¶
Package validator
Package validator implements value validations for structs and individual fields based on tags.
It has the following unique features:
- Cross Field and Cross Struct validations.
- Slice, Array and Map diving, which allows any or all levels of a multidimensional field to be validated.
- Handles type interface by determining it's underlying type prior to validation.
Installation
Use go get.
go get gopkg.in/bluesuncorp/validator.v6
or to update
go get -u gopkg.in/bluesuncorp/validator.v6
Then import the validator package into your own code.
import "gopkg.in/bluesuncorp/validator.v6"
Usage and documentation
Please see http://godoc.org/gopkg.in/bluesuncorp/validator.v6 for detailed usage docs.
package main
import (
"fmt"
"gopkg.in/bluesuncorp/validator.v6"
)
// User contains user information
type User struct {
FirstName string `validate:"required"`
LastName string `validate:"required"`
Age uint8 `validate:"gte=0,lte=130"`
Email string `validate:"required,email"`
FavouriteColor string `validate:"hexcolor|rgb|rgba"`
Addresses []*Address `validate:"required,dive,required"` // a person can have a home and cottage...
}
// Address houses a users address information
type Address struct {
Street string `validate:"required"`
City string `validate:"required"`
Planet string `validate:"required"`
Phone string `validate:"required"`
}
var validate *validator.Validate
func main() {
config := validator.Config{
TagName: "validate",
ValidationFuncs: validator.BakedInValidators,
}
validate = validator.New(config)
validateStruct()
validateField()
}
func validateStruct() {
address := &Address{
Street: "Eavesdown Docks",
Planet: "Persphone",
Phone: "none",
}
user := &User{
FirstName: "Badger",
LastName: "Smith",
Age: 135,
Email: "Badger.Smith@gmail.com",
FavouriteColor: "#000",
Addresses: []*Address{address},
}
// returns nil or ValidationErrors ( map[string]*FieldError )
errs := validate.Struct(user)
if errs != nil {
fmt.Println(errs) // output: Key: "User.Age" Error:Field validation for "Age" failed on the "lte" tag
// Key: "User.Addresses[0].City" Error:Field validation for "City" failed on the "required" tag
err := errs["User.Addresses[0].City"]
fmt.Println(err.Field) // output: City
fmt.Println(err.Tag) // output: required
fmt.Println(err.Kind) // output: string
fmt.Println(err.Type) // output: string
fmt.Println(err.Param) // output:
fmt.Println(err.Value) // output:
// from here you can create your own error messages in whatever language you wish
return
}
// save user to database
}
func validateField() {
myEmail := "joeybloggs.gmail.com"
errs := validate.Field(myEmail, "required,email")
if errs != nil {
fmt.Println(errs) // output: Key: "" Error:Field validation for "" failed on the "email" tag
return
}
// email ok, move on
}
Benchmarks
NOTE: allocations for structs are up from v5, however ns/op for parallel operations are way down. It was a decicion not to cache struct info because although it reduced allocation to v5 levels, it hurt parallel performance too much.
$ go test -cpu=4 -bench=. -benchmem=true
PASS
BenchmarkFieldSuccess-4 5000000 326 ns/op 16 B/op 1 allocs/op
BenchmarkFieldFailure-4 5000000 327 ns/op 16 B/op 1 allocs/op
BenchmarkFieldOrTagSuccess-4 500000 2738 ns/op 20 B/op 2 allocs/op
BenchmarkFieldOrTagFailure-4 1000000 1341 ns/op 384 B/op 6 allocs/op
BenchmarkStructSimpleSuccess-4 1000000 1282 ns/op 24 B/op 3 allocs/op
BenchmarkStructSimpleFailure-4 1000000 1870 ns/op 529 B/op 11 allocs/op
BenchmarkStructSimpleSuccessParallel-4 5000000 348 ns/op 24 B/op 3 allocs/op
BenchmarkStructSimpleFailureParallel-4 2000000 807 ns/op 529 B/op 11 allocs/op
BenchmarkStructComplexSuccess-4 200000 8081 ns/op 368 B/op 30 allocs/op
BenchmarkStructComplexFailure-4 100000 12418 ns/op 2861 B/op 72 allocs/op
BenchmarkStructComplexSuccessParallel-4 500000 2249 ns/op 369 B/op 30 allocs/op
BenchmarkStructComplexFailureParallel-4 300000 5183 ns/op 2863 B/op 72 allocs/op
How to Contribute
There will always be a development branch for each version i.e. v1-development. In order to contribute,
please make your pull requests against those branches.
If the changes being proposed or requested are breaking changes, please create an issue, for discussion or create a pull request against the highest development branch for example this package has a v1 and v1-development branch however, there will also be a v2-development brach even though v2 doesn't exist yet.
I strongly encourage everyone whom creates a custom validation function to contribute them and help make this package even better.
License
Distributed under MIT License, please see license file in code for more details.
Documentation
¶
Overview ¶
Package validator implements value validations for structs and individual fields based on tags. It can also handle Cross Field and Cross Struct validation for nested structs and has the ability to dive into arrays and maps of any type.
Why not a better error message? because this library intends for you to handle your own error messages.
Why should I handle my own errors? Many reasons, for us building an internationalized application I needed to know the field and what validation failed so that I could provide an error in the users specific language.
if fieldErr.Field == "Name" {
switch fieldErr.ErrorTag
case "required":
return "Translated string based on field + error"
default:
return "Translated string based on field"
}
Custom Functions ¶
Custom functions can be added
// Structure
func customFunc(topStruct reflect.Value, currentStruct reflect.Value, field reflect.Value, fieldType reflect.Type, fieldKind reflect.Kind, param string) bool {
if whatever {
return false
}
return true
}
validate.RegisterValidation("custom tag name", customFunc)
// NOTES: using the same tag name as an existing function
// will overwrite the existing one
Cross Field Validation ¶
Cross Field Validation can be implemented, for example Start & End Date range validation
// NOTE: when calling validate.Struct(val) topStruct will be the top level struct passed // into the function // when calling validate.FieldWithValue(val, field, tag) val will be // whatever you pass, struct, field... // when calling validate.Field(field, tag) val will be nil // // Because of the specific requirements and field names within each persons project that // uses this library it is likely that custom functions will need to be created for your // Cross Field Validation needs, however there are some build in Generic Cross Field validations, // see Baked In Validators eqfield, nefield, gtfield, gtefield, ltfield, ltefield and Tags below
Multiple Validators ¶
Multiple validators on a field will process in the order defined
type Test struct {
Field `validate:"max=10,min=1"`
}
// max will be checked then min
Bad Validator definitions are not handled by the library
type Test struct {
Field `validate:"min=10,max=0"`
}
// this definition of min max will never succeed
Baked In Validators and Tags ¶
NOTE: Baked In Cross field validation only compares fields on the same struct, if cross field + cross struct validation is needed your own custom validator should be implemented.
NOTE2: comma is the default separator of validation tags, if you wish to have a comma included within the parameter i.e. excludesall=, you will need to use the UTF-8 hex representation 0x2C, which is replaced in the code as a comma, so the above will become excludesall=0x2C
NOTE3: pipe is the default separator of or validation tags, if you wish to have a pipe included within the parameter i.e. excludesall=| you will need to use the UTF-8 hex representation 0x7C, which is replaced in the code as a pipe, so the above will become excludesall=0x7C
Here is a list of the current built in validators:
- Tells the validation to skip this struct field; this is particularily handy in ignoring embedded structs from being validated. (Usage: -) | This is the 'or' operator allowing multiple validators to be used and accepted. (Usage: rbg|rgba) <-- this would allow either rgb or rgba colors to be accepted. This can also be combined with 'and' for example ( Usage: omitempty,rgb|rgba) structonly When a field that is a nest struct in encountered and contains this flag any validation on the nested struct will be run, but none of the nested struct fields will be validated. This is usefull if inside of you program you know the struct will be valid, but need to verify it has been assigned. NOTE: only "required" and "omitempty" can be used on a struct itself. omitempty Allows conditional validation, for example if a field is not set with a value (Determined by the "required" validator) then other validation such as min or max won't run, but if a value is set validation will run. (Usage: omitempty) dive This tells the validator to dive into a slice, array or map and validate that level of the slice, array or map with the validation tags that follow. Multidimensional nesting is also supported, each level you wish to dive will require another dive tag. (Usage: dive) Example: [][]string with validation tag "gt=0,dive,len=1,dive,required" gt=0 will be applied to [] len=1 will be applied to []string required will be applied to string Example2: [][]string with validation tag "gt=0,dive,dive,required" gt=0 will be applied to [] []string will be spared validation required will be applied to string required This validates that the value is not the data types default zero value. For numbers ensures value is not zero. For strings ensures value is not "". For slices, maps, pointers, interfaces, channels and functions ensures the value is not nil. (Usage: required) len For numbers, max will ensure that the value is equal to the parameter given. For strings, it checks that the string length is exactly that number of characters. For slices, arrays, and maps, validates the number of items. (Usage: len=10) max For numbers, max will ensure that the value is less than or equal to the parameter given. For strings, it checks that the string length is at most that number of characters. For slices, arrays, and maps, validates the number of items. (Usage: max=10) min For numbers, min will ensure that the value is greater or equal to the parameter given. For strings, it checks that the string length is at least that number of characters. For slices, arrays, and maps, validates the number of items. (Usage: min=10) eq For strings & numbers, eq will ensure that the value is equal to the parameter given. For slices, arrays, and maps, validates the number of items. (Usage: eq=10) ne For strings & numbers, eq will ensure that the value is not equal to the parameter given. For slices, arrays, and maps, validates the number of items. (Usage: eq=10) gt For numbers, this will ensure that the value is greater than the parameter given. For strings, it checks that the string length is greater than that number of characters. For slices, arrays and maps it validates the number of items. (Usage: gt=10) For time.Time ensures the time value is greater than time.Now.UTC() (Usage: gt) gte Same as 'min' above. Kept both to make terminology with 'len' easier (Usage: gte=10) For time.Time ensures the time value is greater than or equal to time.Now.UTC() (Usage: gte) lt For numbers, this will ensure that the value is less than the parameter given. For strings, it checks that the string length is less than that number of characters. For slices, arrays, and maps it validates the number of items. (Usage: lt=10) For time.Time ensures the time value is less than time.Now.UTC() (Usage: lt) lte Same as 'max' above. Kept both to make terminology with 'len' easier (Usage: lte=10) For time.Time ensures the time value is less than or equal to time.Now.UTC() (Usage: lte) eqfield This will validate the field value against another fields value either within a struct or passed in field. usage examples are for validation of a password and confirm password: Validation on Password field using validate.Struct Usage(eqfield=ConfirmPassword) Validating by field validate.FieldWithValue(password, confirmpassword, "eqfield") nefield This will validate the field value against another fields value either within a struct or passed in field. usage examples are for ensuring two colors are not the same: Validation on Color field using validate.Struct Usage(nefield=Color2) Validating by field validate.FieldWithValue(color1, color2, "nefield") gtfield Only valid for Numbers and time.Time types, this will validate the field value against another fields value either within a struct or passed in field. usage examples are for validation of a Start and End date: Validation on End field using validate.Struct Usage(gtfield=Start) Validating by field validate.FieldWithValue(start, end, "gtfield") gtefield Only valid for Numbers and time.Time types, this will validate the field value against another fields value either within a struct or passed in field. usage examples are for validation of a Start and End date: Validation on End field using validate.Struct Usage(gtefield=Start) Validating by field validate.FieldWithValue(start, end, "gtefield") ltfield Only valid for Numbers and time.Time types, this will validate the field value against another fields value either within a struct or passed in field. usage examples are for validation of a Start and End date: Validation on End field using validate.Struct Usage(ltfield=Start) Validating by field validate.FieldWithValue(start, end, "ltfield") ltefield Only valid for Numbers and time.Time types, this will validate the field value against another fields value either within a struct or passed in field. usage examples are for validation of a Start and End date: Validation on End field using validate.Struct Usage(ltefield=Start) Validating by field validate.FieldWithValue(start, end, "ltefield") alpha This validates that a string value contains alpha characters only (Usage: alpha) alphanum This validates that a string value contains alphanumeric characters only (Usage: alphanum) numeric This validates that a string value contains a basic numeric value. basic excludes exponents etc... (Usage: numeric) hexadecimal This validates that a string value contains a valid hexadecimal. (Usage: hexadecimal) hexcolor This validates that a string value contains a valid hex color including hashtag (#) (Usage: hexcolor) rgb This validates that a string value contains a valid rgb color (Usage: rgb) rgba This validates that a string value contains a valid rgba color (Usage: rgba) hsl This validates that a string value contains a valid hsl color (Usage: hsl) hsla This validates that a string value contains a valid hsla color (Usage: hsla) email This validates that a string value contains a valid email This may not conform to all possibilities of any rfc standard, but neither does any email provider accept all posibilities... (Usage: email) url This validates that a string value contains a valid url This will accept any url the golang request uri accepts but must contain a schema for example http:// or rtmp:// (Usage: url) uri This validates that a string value contains a valid uri This will accept any uri the golang request uri accepts (Usage: uri) base64 This validates that a string value contains a valid base64 value. Although an empty string is valid base64 this will report an empty string as an error, if you wish to accept an empty string as valid you can use this with the omitempty tag. (Usage: base64) contains This validates that a string value contains the substring value. (Usage: contains=@) containsany This validates that a string value contains any Unicode code points in the substring value. (Usage: containsany=!@#?) containsrune This validates that a string value contains the supplied rune value. (Usage: containsrune=@) excludes This validates that a string value does not contain the substring value. (Usage: excludes=@) excludesall This validates that a string value does not contain any Unicode code points in the substring value. (Usage: excludesall=!@#?) excludesrune This validates that a string value does not contain the supplied rune value. (Usage: excludesrune=@) isbn This validates that a string value contains a valid isbn10 or isbn13 value. (Usage: isbn) isbn10 This validates that a string value contains a valid isbn10 value. (Usage: isbn10) isbn13 This validates that a string value contains a valid isbn13 value. (Usage: isbn13) uuid This validates that a string value contains a valid UUID. (Usage: uuid) uuid3 This validates that a string value contains a valid version 3 UUID. (Usage: uuid3) uuid4 This validates that a string value contains a valid version 4 UUID. (Usage: uuid4) uuid5 This validates that a string value contains a valid version 5 UUID. (Usage: uuid5) ascii This validates that a string value contains only ASCII characters. NOTE: if the string is blank, this validates as true. (Usage: ascii) asciiprint This validates that a string value contains only printable ASCII characters. NOTE: if the string is blank, this validates as true. (Usage: asciiprint) multibyte This validates that a string value contains one or more multibyte characters. NOTE: if the string is blank, this validates as true. (Usage: multibyte) datauri This validates that a string value contains a valid DataURI. NOTE: this will also validate that the data portion is valid base64 (Usage: datauri) latitude This validates that a string value contains a valid latitude. (Usage: latitude) longitude This validates that a string value contains a valid longitude. (Usage: longitude) ssn This validates that a string value contains a valid U.S. Social Security Number. (Usage: ssn) ip This validates that a string value contains a valid IP Adress. (Usage: ip) ipv4 This validates that a string value contains a valid v4 IP Adress. (Usage: ipv4) ipv6 This validates that a string value contains a valid v6 IP Adress. (Usage: ipv6) mac This validates that a string value contains a valid MAC Adress defined by go's ParseMAC accepted formats and types see: http://golang.org/src/net/mac.go?s=866:918#L29 (Usage: mac)
Validator notes:
regex a regex validator won't be added because commas and = signs can be part of a regex which conflict with the validation definitions, although workarounds can be made, they take away from using pure regex's. Furthermore it's quick and dirty but the regex's become harder to maintain and are not reusable, so it's as much a programming philosiphy as anything. In place of this new validator functions should be created; a regex can be used within the validator function and even be precompiled for better efficiency within regexes.go. And the best reason, you can submit a pull request and we can keep on adding to the validation library of this package!
Panics ¶
This package panics when bad input is provided, this is by design, bad code like that should not make it to production.
type Test struct {
TestField string `validate:"nonexistantfunction=1"`
}
t := &Test{
TestField: "Test"
}
validate.Struct(t) // this will panic
Index ¶
Examples ¶
Constants ¶
This section is empty.
Variables ¶
var BakedInValidators = map[string]Func{
"required": hasValue,
"len": hasLengthOf,
"min": hasMinOf,
"max": hasMaxOf,
"eq": isEq,
"ne": isNe,
"lt": isLt,
"lte": isLte,
"gt": isGt,
"gte": isGte,
"eqfield": isEqField,
"nefield": isNeField,
"gtefield": isGteField,
"gtfield": isGtField,
"ltefield": isLteField,
"ltfield": isLtField,
"alpha": isAlpha,
"alphanum": isAlphanum,
"numeric": isNumeric,
"number": isNumber,
"hexadecimal": isHexadecimal,
"hexcolor": isHexcolor,
"rgb": isRgb,
"rgba": isRgba,
"hsl": isHsl,
"hsla": isHsla,
"email": isEmail,
"url": isURL,
"uri": isURI,
"base64": isBase64,
"contains": contains,
"containsany": containsAny,
"containsrune": containsRune,
"excludes": excludes,
"excludesall": excludesAll,
"excludesrune": excludesRune,
"isbn": isISBN,
"isbn10": isISBN10,
"isbn13": isISBN13,
"uuid": isUUID,
"uuid3": isUUID3,
"uuid4": isUUID4,
"uuid5": isUUID5,
"ascii": isASCII,
"printascii": isPrintableASCII,
"multibyte": hasMultiByteCharacter,
"datauri": isDataURI,
"latitude": isLatitude,
"longitude": isLongitude,
"ssn": isSSN,
"ipv4": isIPv4,
"ipv6": isIPv6,
"ip": isIP,
"mac": isMac,
}
BakedInValidators is the default map of ValidationFunc you can add, remove or even replace items to suite your needs, or even disregard and use your own map if so desired.
Functions ¶
This section is empty.
Types ¶
type Config ¶
Config contains the options that a Validator instance will use. It is passed to the New() function
type FieldError ¶
type FieldError struct {
Field string
Tag string
Kind reflect.Kind
Type reflect.Type
Param string
Value interface{}
}
FieldError contains a single field's validation error along with other properties that may be needed for error message creation
type Func ¶
type Func func(topStruct reflect.Value, currentStruct reflect.Value, field reflect.Value, fieldtype reflect.Type, fieldKind reflect.Kind, param string) bool
Func accepts all values needed for file and cross field validation topStruct = top level struct when validating by struct otherwise nil currentStruct = current level struct when validating by struct otherwise optional comparison value field = field value for validation param = parameter used in validation i.e. gt=0 param would be 0
type Validate ¶
type Validate struct {
// contains filtered or unexported fields
}
Validate contains the validator settings passed in using the Config struct
Example (Field) ¶
package main
import (
"fmt"
"../validator"
)
func main() {
// This should be stored somewhere globally
var validate *validator.Validate
config := validator.Config{
TagName: "validate",
ValidationFuncs: validator.BakedInValidators,
}
validate = validator.New(config)
i := 0
errs := validate.Field(i, "gt=1,lte=10")
err := errs[""]
fmt.Println(err.Field)
fmt.Println(err.Tag)
fmt.Println(err.Kind) // NOTE: Kind and Type can be different i.e. time Kind=struct and Type=time.Time
fmt.Println(err.Type)
fmt.Println(err.Param)
fmt.Println(err.Value)
}
Output: gt int int 1 0
Example (New) ¶
package main
import (
"../validator"
)
func main() {
config := validator.Config{
TagName: "validate",
ValidationFuncs: validator.BakedInValidators,
}
validator.New(config)
}
Output:
Example (Struct) ¶
package main
import (
"fmt"
"../validator"
)
func main() {
// This should be stored somewhere globally
var validate *validator.Validate
config := validator.Config{
TagName: "validate",
ValidationFuncs: validator.BakedInValidators,
}
validate = validator.New(config)
type ContactInformation struct {
Phone string `validate:"required"`
Street string `validate:"required"`
City string `validate:"required"`
}
type User struct {
Name string `validate:"required,excludesall=!@#$%^&*()_+-=:;?/0x2C"` // 0x2C = comma (,)
Age int8 `validate:"required,gt=0,lt=150"`
Email string `validate:"email"`
ContactInformation []*ContactInformation
}
contactInfo := &ContactInformation{
Street: "26 Here Blvd.",
City: "Paradeso",
}
user := &User{
Name: "Joey Bloggs",
Age: 31,
Email: "joeybloggs@gmail.com",
ContactInformation: []*ContactInformation{contactInfo},
}
errs := validate.Struct(user)
for _, v := range errs {
fmt.Println(v.Field) // Phone
fmt.Println(v.Tag) // required
//... and so forth
Output:
func (*Validate) Field ¶
func (v *Validate) Field(field interface{}, tag string) ValidationErrors
Field validates a single field using tag style validation and returns ValidationErrors NOTE: it returns ValidationErrors instead of a single FieldError because this can also validate Array, Slice and maps fields which may contain more than one error
func (*Validate) FieldWithValue ¶
func (v *Validate) FieldWithValue(val interface{}, field interface{}, tag string) ValidationErrors
FieldWithValue validates a single field, against another fields value using tag style validation and returns ValidationErrors NOTE: it returns ValidationErrors instead of a single FieldError because this can also validate Array, Slice and maps fields which may contain more than one error
func (*Validate) RegisterValidation ¶
RegisterValidation adds a validation Func to a Validate's map of validators denoted by the key NOTE: if the key already exists, the previous validation function will be replaced. NOTE: this method is not thread-safe
func (*Validate) Struct ¶
func (v *Validate) Struct(current interface{}) ValidationErrors
Struct validates a structs exposed fields, and automatically validates nested structs, unless otherwise specified.
type ValidationErrors ¶
type ValidationErrors map[string]*FieldError
ValidationErrors is a type of map[string]*FieldError it exists to allow for multiple errors to be passed from this library and yet still subscribe to the error interface
func (ValidationErrors) Error ¶
func (ve ValidationErrors) Error() string
Error is intended for use in development + debugging and not intended to be a production error message. It allows ValidationErrors to subscribe to the Error interface. All information to create an error message specific to your application is contained within the FieldError found within the ValidationErrors map
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