MVC中简单数据模型（M): Model类

读书笔记：

基于mvc的javascript web富媒体应用开发，

模型和数据

Model类

 

//新建类的函数Object.create,ECMAScript5已经实现

if(typeof Object.create !== 'function'){

 Object.create = function(o){

  function F(){};

  F.prototype = o;

  return new F();

 };

}



//模型

var Model = {

 inherited: function(){},

 created: function(){},

 prototype:{//用于模型实例继承用

  init: function(a){

   console.log(22);

   this.name = 'Model.name'

  }

 },

 //创建模型

 create: function(){

  var o = Object.create(this);

  o.parent = this;

  o.prototype = o.fn = Object.create(this.prototype);//Model.prototype.init

  o.created();

  this.inherited();

  return o;

 },

 //创建模型实例

 init: function(){

  //console.log(this);

  //console.log(this.prototype);//Model.prototype.init

  var instance = Object.create(this.prototype);

  instance.parent = this;

  instance.init.apply(instance, arguments);

  return instance;

 },

 //扩展模型方法

 extend: function(o){

  var extended = o.extended;

  jQuery.extend(this, o);

  if(extended) extended(this);

 },

 //扩展模型实例方法

 include: function(o){

  var included = o.included;

  jQuery.extend(this.prototype, o);

  if(included) includeed(this);

 }

};



//扩展模型find方法

Model.extend({

 find: function(){}

});

//扩展模型实例init方法，会覆盖Model.prototype.init方法



//并扩展load方法

Model.include({

 init: function(attr){

  if(attr) this.load(attr);

 },

 load: function(attributes){

  for(var name in attributes){

   this[name] = attributes[name];

  }

 }

});

//扩展模型属性

Model.records = {};

//扩展模型实例: create,destroy方法及newRecord属性

Model.include({

 newRecord: true,

 create: function(){

  this.newRecord = false;

  this.parent.records[this.id] = this;

 },

 destroy: function(){

  delete this.parent.records[this.id];

 }

});

//扩展模型实例: update方法

Model.include({

 update: function(){

  this.parent.records[this.id] = this;

 }

});

//扩展模型实例: save方法用以实现兼容更新与创建

Model.include({

 save: function(){

  this.newRecord ? this.create() : this.update();

 }

});

//扩展模型方法用于查找记录

Model.extend({

 find: function(id){

  return this.records[id] || 'Unkonw record';

 }

});

使用数据模型创建，保存，查找

var Asset = Model.create();//创建模模型

var asset = Asset.init();//创建数据模型实例1

asset.name = "same, same";

asset.id = 1;

asset.save();

var asset2 = Asset.init();//创建数据模型实例2



asset2.name = "but different";

asset2.id = 2;

asset2.save();

asset2.destroy();

console.log(Asset.find(2));