Validate golang request data with simple rules. Highly inspired by Laravel's request validation.
Install the package using
$ go get github.com/thedevsaddam/govalidator
// or
$ go get gopkg.in/thedevsaddam/govalidator.v1To use the package import it in your *.go code
import "github.com/thedevsaddam/govalidator"
// or
import "gopkg.in/thedevsaddam/govalidator.v1"Validate form-data, x-www-form-urlencoded and query params
package main
import (
"encoding/json"
"fmt"
"net/http"
"github.com/thedevsaddam/govalidator"
)
func handler(w http.ResponseWriter, r *http.Request) {
rules := govalidator.MapData{
"username": []string{"required", "between:3,8"},
"email": []string{"required", "min:4", "max:20", "email"},
"web": []string{"url"},
"phone": []string{"digits:11"},
"agree": []string{"bool"},
"dob": []string{"date"},
}
messages := govalidator.MapData{
"username": []string{"required:আপনাকে অবশ্যই ইউজারনেম দিতে হবে", "between:ইউজারনেম অবশ্যই ৩-৮ অক্ষর হতে হবে"},
"phone": []string{"digits:ফোন নাম্বার অবশ্যই ১১ নম্বারের হতে হবে"},
}
opts := govalidator.Options{
Request: r, // request object
Rules: rules, // rules map
Messages: messages, // custom message map (Optional)
RequiredDefault: true, // all the field to be pass the rules
}
v := govalidator.New(opts)
e := v.Validate()
err := map[string]interface{}{"validationError": e}
w.Header().Set("Content-type", "application/json")
json.NewEncoder(w).Encode(err)
}
func main() {
http.HandleFunc("/", handler)
fmt.Println("Listening on port: 9000")
http.ListenAndServe(":9000", nil)
}Send request to the server using curl or postman: curl GET "http://localhost:9000?web=&phone=&zip=&dob=&agree="
Response
{
"validationError": {
"agree": [
"The agree may only contain boolean value, string or int 0, 1"
],
"dob": [
"The dob field must be a valid date format. e.g: yyyy-mm-dd, yyyy/mm/dd etc"
],
"email": [
"The email field is required",
"The email field must be a valid email address"
],
"phone": [
"ফোন নাম্বার অবশ্যই ১১ নম্বারের হতে হবে"
],
"username": [
"আপনাকে অবশ্যই ইউজারনেম দিতে হবে",
"ইউজারনেম অবশ্যই ৩-৮ অক্ষর হতে হবে"
],
"web": [
"The web field format is invalid"
]
}
}Validate file
Validate application/json or text/plain as raw body
- Validate JSON to simple struct
- Validate JSON to map
- Validate JSON to nested struct
- Validate using custom rule
Validate struct directly
alphaThe field under validation must be entirely alphabetic characters.alpha_dashThe field under validation may have alpha-numeric characters, as well as dashes and underscores.alpha_spaceThe field under validation may have alpha-numeric characters, as well as dashes, underscores and space.alpha_numThe field under validation must be entirely alpha-numeric characters.between:numeric,numericThe field under validation check the length of characters/ length of array, slice, map/ range between two integer or float number etc.numericThe field under validation must be entirely numeric characters.numeric_between:numeric,numericThe field under validation must be a numeric value between the range. e.g:numeric_between:18,65may contains numeric value like35,55. You can also pass float value to check. Moreover, both bounds can be omitted to create an unbounded minimum (e.g:numeric_between:,65) or an unbounded maximum (e.g:numeric_between:-1,).boolThe field under validation must be able to be cast as a boolean. Accepted input aretrue, false, 1, 0, "1" and "0".credit_cardThe field under validation must have a valid credit card number. Accepted cards areVisa, MasterCard, American Express, Diners Club, Discover and JCB cardcoordinateThe field under validation must have a value of valid coordinate.css_colorThe field under validation must have a value of valid CSS color. Accepted colors arehex, rgb, rgba, hsl, hslalike#909, #00aaff, rgb(255,122,122)dateThe field under validation must have a valid date of format yyyy-mm-dd or yyyy/mm/dd.date:dd-mm-yyyyThe field under validation must have a valid date of format dd-mm-yyyy.digits:intThe field under validation must be numeric and must have an exact length of value.digits_between:int,intThe field under validation must be numeric and must have length between the range. e.g:digits_between:3,5may contains digits like2323,12435in:foo,barThe field under validation must have one of the values. e.g:in:admin,manager,usermust contain the values (admin or manager or user)not_in:foo,barThe field under validation must have one value except foo,bar. e.g:not_in:admin,manager,usermust not contain the values (admin or manager or user)emailThe field under validation must have a valid email.floatThe field under validation must have a valid float number.mac_addressThe field under validation must have be a valid Mac Address.min:numericThe field under validation must have a min length of characters for string, items length for slice/map, value for integer or float. e.g:min:3may contains characters minimum length of 3 like"john", "jane", "jane321"but not"mr", "xy"max:numericThe field under validation must have a max length of characters for string, items length for slice/map, value for integer or float. e.g:max:6may contains characters maximum length of 6 like"john doe", "jane doe"but not"john", "jane"len:numericThe field under validation must have an exact length of characters, exact integer or float value, exact size of map/slice. e.g:len:4may contains characters exact length of 4 likeFood, Mood, GoodipThe field under validation must be a valid IP address.ip_v4The field under validation must be a valid IP V4 address.ip_v6The field under validation must be a valid IP V6 address.jsonThe field under validation must be a valid JSON string.latThe field under validation must be a valid latitude.lonThe field under validation must be a valid longitude.regex:regular expressionThe field under validation validate against the regex. e.g:regex:^[a-zA-Z]+$validate the letters.requiredThe field under validation must be present in the input data and not empty. A field is considered "empty" if one of the following conditions are true: 1) The value is null. 2)The value is an empty string. 3) Zero length of map, slice. 4) Zero value for integer or floatsize:integerThe field under validation validate a file size only in form-data (see example)ext:jpg,pngThe field under validation validate a file extension (see example)mime:image/jpg,image/pngThe field under validation validate a file mime type (see example)urlThe field under validation must be a valid URL.uuidThe field under validation must be a valid UUID.uuid_v3The field under validation must be a valid UUID V3.uuid_v4The field under validation must be a valid UUID V4.uuid_v5The field under validation must be a valid UUID V5.
func init() {
// simple example
govalidator.AddCustomRule("must_john", func(field string, rule string, message string, value interface{}) error {
val := value.(string)
if val != "john" || val != "John" {
return fmt.Errorf("The %s field must be John or john", field)
}
return nil
})
// custom rules to take fixed length word.
// e.g: word:5 will throw error if the field does not contain exact 5 word
govalidator.AddCustomRule("word", func(field string, rule string, message string, value interface{}) error {
valSlice := strings.Fields(value.(string))
l, _ := strconv.Atoi(strings.TrimPrefix(rule, "word:")) //handle other error
if len(valSlice) != l {
return fmt.Errorf("The %s field must be %d word", field, l)
}
return nil
})
}Note: Array, map, slice can be validated by adding custom rules.
If you need to translate validation message you can pass messages as options.
messages := govalidator.MapData{
"username": []string{"required:You must provide username", "between:The username field must be between 3 to 8 chars"},
"zip": []string{"numeric:Please provide zip field as numeric"},
}
opts := govalidator.Options{
Messages: messages,
}If you are interested to make the package better please send pull requests or create an issue so that others can fix. Read the contribution guide here
See all contributors
See benchmarks
Read API documentation
The govalidator is an open-source software licensed under the MIT License.
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