关于javascript设计模式书中的接口，记录如下

//TODO  增加了一个判断条件，可以只在生产环境中调用

接口var Interface = function(name,methods){

  if(arguments.length != 2){

   throw new Error('Interface constructor call with' + arguments.length + 'arguments,but expecter exactly 2.')

   }

   this.name = name;

   this.methods = [];

   for(var i = 0, len = methods.length; i < len; i++){

     if(typeof methods[i] !== 'string'){

       throw new Error('Imterface constructor expects method names as to be passed in as a string.')

     }

     this.methods.push(methods[i]);

   }

};

//static class method

Interface.ensureImplements = function(obj){

  if(arguments.length < 2){

    throw new Error('Function Interface.ensureImplements called with'+arguments.length +'arguments,but expected at least 2');

  }

  for(var i = 1, len = arguments.length; i < len; i++){

    var interface = arguments[i];

    if(interface.constructor !== Interface){

       throw new Error('Function Interface.ensureImplements expects arguments two and above to be instances of Interface.')

     }

     for(var j = 0, methodsLen = interface.methods.length; j < methodsLen; j++){

       var method = interface.methods[j];

       if(!obj[method] || typeof obj[method] !== 'function'){

         throw new Error('Function Interface.ensureImplements: obj does\'s implement the '+ interface.name + ' interface.Method '+method +' was\'s found')

       }

    }

  }

  //TODO  pass

  return true;

};

用法如下：

接口//TODO define Interface

var Composite = new Interface('Composite',['add','remove','getChild']);

var FormItem = new Interface('FormItem',['save']);

//TODO  checkout implements

function addForm(formInstace,isDevelop){

  isDevelop && Interface.ensureImplements(formInstace, Composite, FormItem)

  //其他使用add,remove,getchild,save函数的代码段

}

//CompositeForm class

var CompositeForm = function(id, method, action){};

CompositeForm.prototype = {

  add: function(){},

  remove:function(){},

  getChild:function(){}

  ,save:function(){}

};

var testCompositeForm = new CompositeForm()

addForm(testCompositeForm,true)

 1 //TODO define Interface
 2 var Composite = new Interface('Composite',['add','remove','getChild']);
 3 var FormItem = new Interface('FormItem',['save']);
 4 
 5 //TODO  checkout implements
 6 function addForm(formInstace,isDevelop){
 7   isDevelop && Interface.ensureImplements(formInstace, Composite, FormItem)
 8   //其他使用add,remove,getchild,save函数的代码段
 9 }
 //CompositeForm class
 var CompositeForm = function(id, method, action){};
 CompositeForm.prototype = {
   add: function(){},
   remove:function(){},
   getChild:function(){}
   ,save:function(){}
 };
 
 var testCompositeForm = new CompositeForm()
 addForm(testCompositeForm,true)

use