map value validation

[cch123]

Package version eg. v8, v9:

v9

Issue, Question or Enhancement:

Is it possible to add map validation support

Code sample, to showcase or reproduce:

maybe like following:

validationMap := map[string]string{
    "key"  :  "gt=10",
    "key2" : "len=10"
}

targetMap := map[string]interface{} {
    "key" : "yes",
    "key2" : "anyway1234",
}

validate.Map(validationMap, targetMap)

[deankarn]

Hey @cch123

On a key by Key basis no, there is not support for that specific scenario; I'd add such a thing but unfortunately there would be varying opinions on exactly how it should work i.e. should all keys have to match in the maps or not....

Once logic is this specific I recommend creating custom validation, it's pretty easy :)

package main

import (
	"fmt"

	"gopkg.in/go-playground/validator.v9"
)

func main() {

	validationMap := map[string]string{
		"key":  "gt=10",
		"key2": "len=10",
	}

	validate := validator.New()
	validate.RegisterValidation("mapval", func(fl validator.FieldLevel) bool {
		m, ok := fl.Field().Interface().(map[string]interface{})
		if !ok {
			return false
		}

		for k, v := range validationMap {
			if validate.Var(m[k], v) != nil {
				return false
			}
		}

		return true
	})

	targetMap := map[string]interface{}{
		"key":  "yes",
		"key2": "anyway1234",
	}

	errs := validate.Var(targetMap, "mapval")
	fmt.Println(errs)
}

or if you want a completely generic validation function you can also pass the validation map in the context eg.

package main

import (
	"context"
	"fmt"

	"gopkg.in/go-playground/validator.v9"
)

var MapValKey = struct {
	name string
}{
	name: "validation func",
}

func main() {

	validate := validator.New()
	validate.RegisterValidationCtx("mapval", func(ctx context.Context, fl validator.FieldLevel) bool {
		m, ok := fl.Field().Interface().(map[string]interface{})
		if !ok {
			return false
		}

		vm, ok := ctx.Value(MapValKey).(map[string]string)

		for k, v := range vm {
			if validate.Var(m[k], v) != nil {
				return false
			}
		}

		return true
	})

	targetMap := map[string]interface{}{
		"key":  "yes",
		"key2": "anyway1234",
	}

	validationMap := map[string]string{
		"key":  "gt=10",
		"key2": "len=10",
	}
	ctx := context.WithValue(context.Background(), MapValKey, validationMap)

	errs := validate.VarCtx(ctx, targetMap, "mapval")
	fmt.Println(errs)
}

I did discover a bug while making these examples, so be sure to update to the latest validator.

please let me know if this helps :)

[cch123]

@joeybloggs , thx a lot! This solves my problem.

[jpfluger]

This was a great example. Thanks! 👍

[JoveYu]

@deankarn how about map in map validation?