Validations
Validations provides a means to validate GORM models when creating and updating them.
Register GORM Callbacks
Validations uses GORM callbacks to handle validations, so you will need to register callbacks first:
import (
"github.com/jinzhu/gorm"
"github.com/qor/validations"
)
func main() {
db, err := gorm.Open("sqlite3", "demo_db")
validations.RegisterCallbacks(db)
}
Usage
After callbacks have been registered, attempting to create or update any record will trigger the Validate method that you have implemented for your model. If your implementation adds or returns an error, the attempt will be aborted.
type User struct {
gorm.Model
Age uint
}
func (user User) Validate(db *gorm.DB) {
if user.Age <= 18 {
db.AddError(errors.New("age need to be 18+"))
}
}
db.Create(&User{Age: 10}) // won't insert the record into database, as the `Validate` method will return error
var user User{Age: 20}
db.Create(&user) // user with age 20 will be inserted into database
db.Model(&user).Update("age", 10) // user's age won't be updated, will return error `age need to be 18+`
// If you have added more than one error, could get all of them with `db.GetErrors()`
func (user User) Validate(db *gorm.DB) {
if user.Age <= 18 {
db.AddError(errors.New("age need to be 18+"))
}
if user.Name == "" {
db.AddError(errors.New("name can't be blank"))
}
}
db.Create(&User{}).GetErrors() // => []error{"age need to be 18+", "name can't be blank"}
Govalidator integration
Qor Validations supports govalidator, so you could add a tag into your struct for some common validations, such as check required, numeric, length, etc.
type User struct {
gorm.Model
Name string `valid:"required"`
Password string `valid:"length(6, 20)"`
SecurePassword string `valid:"numeric"`
Email string `valid:"email"`
}
Customize errors on form field
If you want to display errors for each form field in QOR Admin, you could register your error like this:
func (user User) Validate(db *gorm.DB) {
if user.Age <= 18 {
db.AddError(validations.NewError(user, "Age", "age need to be 18+"))
}
}
Try it out for yourself
Checkout the http://demo.getqor.com/admin/products/1 demo, change Name to be a blank string and save to see what happens.
License
Released under the MIT License.