MVC和命名空间
var User = function(atts) {
this.attribute = atts || {};
}
//和具体user相关的方法
User.prototype.destroy = function() {};
//和具体user不相关的函数和变量
User.fetchRemove = function() {};
var user = new User({name:'jinks'});
user.destroy();
构建对象关系映射
如：
- 任何model的改变会向后台发起一个ajax请求
- model和view绑定，当一个实例改变时，马上从view中反映出来
原型继承
- 这里用到Object.create,对于没有的浏览器，可以模拟方法
if(typeof Object.create !== "function") {
Object.create = function(o) {
function F(){};
F.prototype = o;
return new F();
}
}
var Model = {
inherited: function() {},
created: function() {},
prototype: {
init: function() {}
},
create: function() {
var object = Object.create(this);
object.parent = this;
object.prototype = object.fn = Object.create(this.prototype);
object.created();
this.inherited(object);
return object;
},
init: function() {
var instance = Object.create(this.prototype);
instance.parent = this;
instance.init.apply(instance, arguments);
return instance;
}
}
var Asset = Model.create();
var User = Model.create();
var user = User.init();
添加ORM属性
var Model = {
/*代码片段*/
extend: function(o) {
var extended = o.extended;
for(var i in o) {
this[i] = o[i];
}
if(extended) extended(this);
},
include: function(o) {
var included = o.included;
for(var i in o) {
this.prototype[i] = o[i];
}
if(included) included(this);
}
}
//添加到Model对象属性
Model.extend({
find: function() {}
});
//添加Model.prototype中，所有实例共享这一属性
Model.include({
load: function(atts) {
for(var i in atts) {
this[i] = atts[i];
}
},
init: function(atts) {
if(atts) this.load(atts);
}
});
var Asset = Model.create();
var asset = Asset.init({name: "a.png"});
持久化记录
将引用保存至新创建的实例中以便任何时候都可以访问
var Model = {
/*代码*/
}
//用来保存资源的对象
Model.records = {};
Model.include({
newRecord: true,
create: function() {
this.newRecord = false;
this.parent.records[this.id] = this;
},
destroy: function() {
delete this.parent.records[this.id];
}
});
//更新一个已经存在的实例
Model.include({
update: function() {
this.parent.records[this.id] = this;
}
});
//添加一个快捷函数来保持实例
Model.include({
save: function() {
this.newRecord ? this.create() : this.update();
}
});
Model.extend({
//通过id查找，找不到抛出异常
find: function(id) {
var id = this.records[id];
if(id) {
return id;
} else {
throw new Error("Unknow record");
}
}
});
var Asset = Model.create();
var asset = Asset.init();
asset.name = "same, same";
asset.id = 1;
asset.save();
var asset2 = Asset.init();
asset2.name = "but different";
asset2.id = 2;
asset2.save();
console.log(Asset.records);
asset2.destroy();
console.log(Asset.records);
增加ID支持
使用全局统一标识(GUID)生成器来自动生成ID
//使用Math.random()来产生一个伪随机数的GUID
Math.guid = function(){
return 'xxxxxxxx-xxxx-4xxx-yxxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function(c){
var r = Math.random() * 16 | 0,
v = c === 'x' ? r : (r & 0x3 | 0x8);
return v.toString(16)
}).toUpperCase();
};
//修改create()函数
Model.include({
create: function() {
if(!this.id) this.id = Math.guid();
this.newRecord = false;
this.parent.records[this.id] = this;
}
});
var Asset = Model.create();
var asset = Asset.init();
asset.save();
console.log(asset.id);