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.
Use go get.
go get gopkg.in/go-playground/validator.v5
or to update
go get -u gopkg.in/go-playground/validator.v5
Then import the validator package into your own code.
import "gopkg.in/go-playground/validator.v5"
Please see http://godoc.org/gopkg.in/go-playground/validator.v5 for detailed usage docs.
package main
import (
"fmt"
"gopkg.in/go-playground/validator.v5"
)
// 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() {
validate = validator.New("validate", validator.BakedInValidators)
address := &Address{
Street: "Eavesdown Docks",
Planet: "Persphone",
Phone: "none",
}
user := &User{
FirstName: "Badger",
LastName: "Smith",
Age: 135,
Email: "[email protected]",
FavouriteColor: "#000",
Addresses: []*Address{address},
}
// returns nil or *StructErrors
errs := validate.Struct(user)
if errs != nil {
// err will be of type *FieldError
err := errs.Errors["Age"]
fmt.Println(err.Error()) // output: Field validation for "Age" failed on the "lte" tag
fmt.Println(err.Field) // output: Age
fmt.Println(err.Tag) // output: lte
fmt.Println(err.Kind) // output: uint8
fmt.Println(err.Type) // output: uint8
fmt.Println(err.Param) // output: 130
fmt.Println(err.Value) // output: 135
// or if you prefer you can use the Flatten function
// NOTE: I find this usefull when using a more hard static approach of checking field errors.
// The above, is best for passing to some generic code to say parse the errors. i.e. I pass errs
// to a routine which loops through the errors, creates and translates the error message into the
// users locale and returns a map of map[string]string // field and error which I then use
// within the HTML rendering.
flat := errs.Flatten()
fmt.Println(flat) // output: map[Age:Field validation for "Age" failed on the "lte" tag Addresses[0].Address.City:Field validation for "City" failed on the "required" tag]
err = flat["Addresses[0].Address.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
}
$ go test -cpu=4 -bench=. -benchmem=true
PASS
BenchmarkValidateField-4 3000000 429 ns/op 192 B/op 2 allocs/op
BenchmarkValidateStructSimple-4 500000 2877 ns/op 657 B/op 10 allocs/op
BenchmarkTemplateParallelSimple-4 500000 3097 ns/op 657 B/op 10 allocs/op
BenchmarkValidateStructLarge-4 100000 15228 ns/op 4350 B/op 62 allocs/op
BenchmarkTemplateParallelLarge-4 100000 14257 ns/op 4354 B/op 62 allocs/op
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.
Distributed under MIT License, please see license file in code for more details.