Handling JSON NULL

原文： http://extjs.com/forum/showthread.php?t=46336

通过为Ext.data.JsonReader的字段加上convert来处理条件映射的问题。

示例如下：

{"licences":[{"Id":2,"LicenseKey":"123456","Point":null,"Owner":{"Id":1,"Name":"Witbit"}, "Mac":null,"Active":false},

{"Id":3,"LicenseKey":"789013","Point":null,"Owner":null, "Mac":null,"Active":false}]} 

this.DS  = new Ext.data.Store(

{

    reader: new Ext.data.JsonReader(

            { 

                root: "licences",

                fields: [ "Id", "LicenseKey", {name:"Owner_Name", mapping:"Owner.Name"}, "Point",  "Mac", "Active" ] 

            })

}); 

修改Owerne.Name的Mapping方式为下面：

{name:"Owner_Name", mapping:"Owner", convert: function(v) {return v ? v.Name : null;}}