从ExtJS 4中的自定义模型类扩展

Question

如何从extjs中的自定义模型扩展.

当我在下面的示例中引用BusinessUser类中的字段时,是否有任何方法可以直接支持User和BusinessUser字段的字段.

Ext.define('User', {
    extend: 'Ext.data.Model',
    fields: [
        {name: 'name',  type: 'string'},
        {name: 'age',   type: 'int'},
        {name: 'phone', type: 'string'},
        {name: 'alive', type: 'boolean', defaultValue: true}
    ],
});

Ext.define('BusinessUser', {
    extend: 'User',
    fields: [
        {name: 'businessType',  type: 'string'},
        {name: 'company', type: 'string'}
    ],
});

Answer 1

您无需手动加入字段,因为它是自动完成的.根据您的问题检查以下代码中的输出:

Ext.define('User', {
    extend: 'Ext.data.Model',
    fields: [
        {name: 'name',  type: 'string'},
        {name: 'age',   type: 'int'},
        {name: 'phone', type: 'string'},
        {name: 'alive', type: 'boolean', defaultValue: true}
    ],
});

Ext.define('BusinessUser', {
    extend: 'User',
    fields: [
        {name: 'businessType',  type: 'string'},
        {name: 'company', type: 'string'}
    ],
});

// instantiating a User object
var u = Ext.create('BusinessUser', {
    name: 'John Doe', 
    age: 30, 
    phone: '555-5555'
});

// instantiating a BusinessUser object
var bu = Ext.create('BusinessUser', {
    name: 'Jane Doe', 
    age: 40, 
    phone: '555-5556', 
    businessType: 'analyst', 
    company: 'ACME'
});

console.log(Ext.getClassName(bu)); // "BusinessUser"
console.log(Ext.getClassName(u));  // "User"
console.log(u  instanceof User); // true
console.log(bu instanceof User); // true
console.log(u  instanceof BusinessUser); // false
console.log(bu instanceof BusinessUser); // true
console.log(u  instanceof Ext.data.Model); // true
console.log(bu instanceof Ext.data.Model); // true
console.log(u  instanceof Ext.data.Store); // false, just to check if it's not returning true for anything
console.log(bu instanceof Ext.data.Store); // false
console.log("name"    in u.data);  // true
console.log("name"    in bu.data); // true
console.log("company" in u.data);  // false
console.log("company" in bu.data); // true

Answer 2

虽然它应该自动工作,但如果您因某些原因遇到麻烦,请使用下面的内容.

使用构造函数来加入字段:

Ext.define('BusinessUser', {
   extend : 'User',
   constructor : function(){
      this.callParent(arguments);
      this.fields.push([
        {name: 'businessType',  type: 'string'},
        {name: 'company', type: 'string'}
    ]);
   }
});