Support for custom validators with parameters

[a-chernykh]

I am trying to use govalidator in one of my projects but struggling to implement validator for password confirmation:

type UserForm struct {
	Email                string `valid:"required,email"`
	Password             string `valid:"required,confirmation(PasswordConfirmation)"`
	PasswordConfirmation string `valid:"required"`
}

It looks like custom validators can not accept any parameters at the moment.

I understand that I can use a workaround by hard-coding PasswordConfirmation field name in my custom validator, but I would like it to be re-usable.

I was wondering if there will be any interest in implementing this feature? If yes, then I can implement it and send a PR.

[yuz989]

+1, would be great to support custom ParamValidator

[asaskevich]

@andreychernih it would be great!

[jasonlam604]

+1

[Syam]

+1

[naoric]

I know this one is pretty old, and you guys probably know how to do this, but just in case someone else like me stumbles upon this issue - I found a way to do this:

type User struct {
  CompanyID string `valid:"exists(a|b)"`
}

var existingValidatorRegex = regexp.MustCompile("^exists\\((.+)\\|(.+)\\)$")

func InitValidators() {
	ParamTagMap["exists"] = ParamValidator(existingValidator)
	ParamTagRegexMap["exists"] = existingValidatorRegex
}

func existingValidator(val string, params ...string) bool {
	fmt.Println(val, params)
	return params[0] == "a" && params[1] == "b"
}

I'm not sure if the official API supports this but it seems to be working. Please let me know if I'm wrong.

[petherin]

@naoric This is how we've been forced to do it too. It seems to work, but it'd be nicer to have a neater way of doing this.

[okisetiawan0101]

You can create something like this. I've implemented it in my code and it works.

Here is the simple example with 1 parameter (you can add more parameters as you want)

// Add your own struct validation tags with parameter
govalidator.ParamTagMap["animal"] = govalidator.ParamValidator(func(str string, params ...string) bool {
    species := params[0]
    return str == species
})

//register the regex for validate
govalidator.ParamTagRegexMap["animal"] = regexp.MustCompile("^animal\\((\\w+)\\)$")

If you validate this struct, the validator will return true

type Post struct {
	Test string `valid:"animal(dog)"`
}

If you validate this struct, the validator will return false

type Post struct {
	Test string `valid:"animal(cat)"`
}

[sergeyglazyrindev]

Hello guys! I forked this package cause owner disappeared. Hope, he will be back, but it would be easier to merge these changes back if he is back Link to my repo: create issue there and we'll discuss it.