Prototype Pattern，在jQuery中使用'this'$ .each函數

Question

我想通過我的object中的XML數據構建<select>。我想使用原型模式，我不得不承認我對模式很陌生。下面是我有：

HTML樣本：

<select id="ddFullName" name="Full_Name" ></select> 

XML示例：

<names> 
    <nameDetails name="Name 01" phone="555-867-5309" email="none@nothing.no" /> 
    <nameDetails name="Name 02" phone="555-867-5309" email="none@nothing.no" /> 
    <nameDetails name="Name 03" phone="555-867-5309" email="none@nothing.no" /> 
    <nameDetails name="Name 04" phone="555-867-5309" email="none@nothing.no" /> 
    <nameDetails name="Name 05" phone="555-867-5309" email="none@nothing.no" /> 
</names> 

的JavaScript樣本：

function buildNameDropdown(data, elem) { 
    this.data = data; 
    this.name = $(data).find('nameDetails'); 
    this.elem = elem; 

    buildNameDropdown.prototype.init = function() 
    { 
     //Working as desired 
     $(this.elem).append($('<option value=""> ----- Select a Name ----- </option>')); 
     //Not working 
     $(this.name).each(function() 
     { 
      //$(this) = the object, not 'this.name' 
      $(this.elem).append($('<option value="' + $(this).attr('name') + '">' + $(this).attr('name') + '</option>')); 

     }); 
     $(this.elem).combobox(); // from jQuery UI combobox extension 
    }; 
}; 


var myNameDropdown = new buildNameDropdown(data, "#ddFullName"); 
myNameDropdown.init(); 

我想如何引用'this'作爲每個函數的選擇器？

Answer 1

將this引用複製到局部變量。這樣它將在關閉回調函數中可用。

（旁註：你不應該設置原型在構造函數中，這樣，你會重新分配它爲您創建的每個實例。）

function buildNameDropdown(data, elem) { 
    this.data = data; 
    this.name = $(data).find('nameDetails'); 
    this.elem = elem; 
}; 

buildNameDropdown.prototype.init = function() { 
    $(this.elem).append($('<option value=""> ----- Select a Name ----- </option>')); 
    var t = this;  
    $(this.name).each(function() { 
    $(t.elem).append($('<option value="' + $(this).attr('name') + '">' + $(this).attr('name') + '</option>')); 
    }); 
    $(this.elem).combobox(); // from jQuery UI combobox extention 
};