javascript - 如何扩展 Sequelize 模型

Question

有没有办法扩展（可能继承）模型以在定义模型后添加钩子和字段？

所以是这样的：

User = sequelize.define("user", {
   name: sequelize.String
});

makeStateful(User); // adds state,updated,added fields and some hooks

Answer 1

目前这是不可能的。但是你可以很容易地让它以相反的方式工作：在定义模型之前定义你的 mixin 并在定义模型时使用它：

var Sequelize = require('sequelize')
  , sequelize = new Sequelize('sequelize_test', 'root')

var mixin = {
  attributes: {
    state: Sequelize.STRING,
    added_at: Sequelize.DATE
  },
  options: {
    hooks: {
      beforeValidate: function(instance, cb) {
        console.log('Validating!!!')
        cb()
      }
    }
  }
}

var User = sequelize.define(
  'Model'
, Sequelize.Utils._.extend({
    username: Sequelize.STRING
  }, mixin.attributes)
, Sequelize.Utils._.extend({
    instanceMethods: {
      foo: function() {
        return this.username
      }
    }
  }, mixin.options)
)

User.sync({ force: true }).success(function() {
  User.create({ username: 'foo' }).success(function(u) {
    console.log(u.foo()) // 'foo'
  })
})