Live demo

A User model with three validation rules, running in this page against the library source. Edit the fields, then call validate(), reset() or sync() and watch changed() and the event log.

nameemailage

changed() → false

toJSON() → { "name": "Ada", "email": "ada@example.com", "age": 36 }

saved('name') → Ada

class User extends Model<UserAttrs> {
  defaults() {
    return { name: '', email: '', age: 18 }
  }

  validation() {
    return {
      name: required,
      email: required.and(email),
      age: required.and(between(18, 120))
    }
  }
}

const user = new User({ name: 'Ada', email: 'ada@example.com', age: 36 })
user.sync()

user.on('change', ({ attribute, value }) => console.log(attribute, value))
await user.validate()   // { email: ['Invalid email'] } when the address is broken
user.changed()          // ['name'] after you edit the name
user.reset()            // back to the synced state