修改Model中hasMany中自动生成的属性值

在学习EXTJS的文档是，在测试《The Data Package》中的例子时，文中讲到Model中的hasMany自动生成的是一个Store对象的引用，如hasMany: 'Post'，自动生成的是post()方法，实际上指向的Post的Store引用。自动生成的Store在向后台请求数据时的Get参数为：posts/?_dc=1342322365337&limit=25&page=1&start=0&filter=%5B%7B%22property%22%3A%22user_id%22%2C%22value%22%3A1%7D%5D，其中limit的值为25，这是默认值，如果想要修改这个默认值，可以调用：user.posts().proxy.setExtraParam("limit", 100);进行修改。完整代码如下：

/**
* @example Lazy Associations
*
* This example demonstrates lazy loading of a {@link Ext.data.Model}'s associations only when requested.
* a `User` model is loaded, then a separate request is made for the `User`'s associated `Post`s
* See console for output.
*/

// define the User model
Ext.define('User', {
extend: 'Ext.data.Model',
fields: ['id', 'name', 'age', 'gender'],

proxy: {
type: 'rest',
url : 'data/users',
reader: {
type: 'json',
root: 'users'
}
},

hasMany: 'Post' // shorthand for {model: 'Post', name: 'posts'}
});

//define the Post model
Ext.define('Post', {
extend: 'Ext.data.Model',
fields: ['id', 'user_id', 'title', 'body'],

proxy: {
type: 'rest',
url : 'data/posts',
reader: {
type: 'json',
root: 'posts'
}
},

belongsTo: 'User',
hasMany: {model: 'Comment', name: 'comments'}
});

//define the Comment model
Ext.define('Comment', {
extend: 'Ext.data.Model',
fields: ['id', 'post_id', 'name', 'message'],

belongsTo: 'Post'
});

Ext.require('Ext.data.Store');
Ext.onReady(function () {
// Loads User with ID 1 User's Proxy
User.load(1, {
success: function (user) {
console.log("User: " + user.get('name'));

// Loads posts for user 1 using Post's Proxy
user.posts().proxy.setExtraParam("limit", 100);
user.posts().load({
callback: function (posts, operation) {
Ext.each(posts, function (post) {
console.log("Comments for post: " + post.get('title'));

post.comments().each(function (comment) {
console.log(comment.get('message'));
});
});
}
});
}
});
});