Struct validation library

ATTENTION: work in progress

Purpose

A small validation library that allows to have multiple different validations on the same struct.

Usage

Example: a struct used for both cases, sign up and sign in:

type UserAuth struct {
	Email                string `signup:"email" signin:"email"`
	Password             string `signup:"notempty,eq=PasswordConfirmation" signin:"notempty"`
	PasswordConfirmation string `signup:"notempty"`
}

usr := UserAuth{...}

Init validator and register schemas:

v := val4go.New()
v.RegisterSchema("signup")
v.RegisterSchema("signin")

Validate based on use case:

errs := v.Validate("signup", usr)

or

errs := v.Validate("signin", usr)

Validations

Field validations:

reguired

Checks to not be nil Only pointers, slice and map are supported.

Name *string `signup:"reguired"`

notempty

Checks to be non-zero values. Only string and slice are supported.

If field is a pointer, it checks first to not be nil

Name string `signup:"notempty"`

email

Checks to be a valid email.

If field is a pointer, it checks first to not be nil

Email string `signup:"email"`

min

Checks a minimum length/value.

Only string, int, int8, int16, int32, int64 are supported.

If field is a pointer, it checks first to not be nil

Name string `signup:"min=4"`

max

Checks a maximum length/value.

Only string, int, int8, int16, int32, int64 are supported.

If field is a pointer, it checks first to not be nil

Name string `signup:"max=4"`

date

Checks if it's an iso date.

Date string `signup:"date"`

Cross-field validations:

eq

Checks an equality with the cross given field value.

Password             string `signup:"eq=PasswordConfirmation"`
PasswordConfirmation string

Custom validations:

v := val4go.New()

v.RegisterValidation("my-validation", func(vf reflect.Value, sf reflect.StructField, v reflect.Value, cf string) error {
	// vf -> reflect.Value of a field being validated
	// sf -> reflect.StructField of a field being validated
	// v  -> reflect.Value of a struct being validated
	// cf -> string of a cross field name

	// validate
	return err
})

type UserAuth struct {
	Email                string `signup:"my-validation"`
}

v.RegisterSchema("signup")