[来自：Backbone.js 开发秘笈 第3章]
Collection API
(function ($) {
//define -----------------------------
var ModelD = Backbone.Model.extend({
defaults: {
ID: 0,
Name: ‘‘
},
idAttribute: ‘ID‘
});
//定义集合对象
/* 在其内部，模型被存储在一个名为 models 的数组当中 */
var CollectionD = Backbone.Collection.extend({
model: ModelD
});
//instance ---------------------------
var modelInstance = new ModelD({
ID: 1,
Name: ‘James‘
});
//实例化集合对象
var collectionInstance = new CollectionD([
{ ID: 2, Name: ‘Yoyo‘ },
modelInstance
]);
//apply -----------------------------
//获取索引处的集合项
var model2 = collectionInstance.at(1);
//获取模型索引值
var model2Index = collectionInstance.indexOf(modelInstance);
//获取集合长度
var count = collectionInstance.length;
//获取指定 ID 的模型
/* 通过其内部 _byId 键值对集合进行查询 */
var model1 = collectionInstance.get(2);
//添加模型 [重复不会添加到集合中，触发 add 事件]
collectionInstance.add([{
ID: 3,
Name: ‘Pepe‘
}], {
at: 0//插入点
});
//删除模型
collectionInstance.remove([3]);
//重置模型
collectionInstance.reset([{
ID: 4,
Name: ‘Ramos‘
}]);
//以队列或栈的形式操作
/*
.push()
.pop()
.unshift()
.shift()
*/
//排序
/* 注：定义 comparator 回调函数后，插入值后会被调用来确保顺序 */
collectionInstance.comparator = function (model) {
return model.get(‘Name‘);
};
//或
/*
collectionInstance.comparator = function(m1, m2) {
return m1.get(‘ID‘) - m2.get(‘ID‘);
};
*/
/* 模型被更新后，需手动调用 sort() 进行排序或绑定到 change 事件 */
collectionInstance.sort();
//过滤集合
var collection2 = collectionInstance.where({ Name: ‘Pepe‘ });
//遍历集合
collectionInstance.each(function (mode, index, list) {
});
//是否都满足条件
var isMultiple = collectionInstance.every(function (model) {
return model.get(‘ID‘) > 0;
});
//是否任意满足条件
var isOther = collectionInstance.some(function (model) {
return mode.get(‘ID‘) === 0;
});
//获取集合指定属性的值集合
var names = collectionInstance.pluck(‘Name‘);
//获取集合特定的值集合
var plusColl = collectionInstance.map(function (model) {
return model.get(‘ID‘) + model.get(‘Name‘);
});
//获取归并单一值
var plusID = collectionInstance.reduce(function (plusValue, model) {
return (plusValue || 0) + model.get(‘ID‘);
}, 0/*初始值*/);
//集合的链式操作 /* chain() */
var plusID2 = collectionInstance.chain().pluck(‘ID‘).reduce(function (plusValue, value) {
return plusValue + value;
}, 0).value();
})(jQuery);
插件扩展：
1. NoSQL 查询 more api
(function ($) {
//依赖 backbone.query.js
//https://github.com/davidgtonge/backbone_query
//define --------------------------------------
var ModelQ = Backbone.Model.extend({
defaults: {
id: 0,
name: ‘‘,
age: 0,
rank: 1001
}
});
//通过其基类进行插件扩展
var CollectionQ = Backbone.QueryCollection.extend({
model: ModelQ
});
//instance ----------------------------------------
var collectionInstance = new CollectionQ([
{ id: 1, name: ‘cxls‘, age: 33, rank: 1999 },
{ id: 2, name: ‘yln‘, age: 22, rank: 1003 },
{ id: 3, name: ‘pp‘, age: 31, rank: 1899 },
{ id: 1, name: ‘lms‘, age: 28, rank: 1899 }
]);
//apply --------------------------------------------
//查询
var qCollection = collectionInstance.query({ name: ‘cxls‘ });
/* 操作符 */
/*
$equal ===
$ne !==
$in 包含所有可能的数组的值 [1899,1999]
$nin !$in
$exists 是否存在 true or flase
$has 是否存在 true or flase
$and
$or
$nor !$or
$not !$and
*/
qCollection = collectionInstance.query({ rank: { $equal: 1299 } });
qCollection = collectionInstance.query({ $and: { age: 31, rank: 1299 } });
//排序
var oCollection = collectionInstance.query({ sortBy: ‘name‘, order: ‘desc‘/* 默认 asc */ });
//分页
var pCollection = collectionInstance.query({ rank: 1999 }, {
limit: 10/*返回结果数组的前 N 个元素 (必填) */,
offset: 1/* 跳过前 N 个结果项 */,
page: 2,/* 指定结果页 */
cache: true/* 是否缓存数据 默认 false */
});
/* 注：缓存后如有更新，则许手动同步缓存，可以通过调用 resetQueryCache() 方法 */
})(jQuery);
2. 集合存储不同类型模型
(function ($) {
//依赖 backbone.chosen.js
//https://github.com/asciidisco/backbone.Chosen
//define --------------------------------------
var Model1 = Backbone.Model.extend({
getFullName: function () {
return this.get(‘firstName‘) + this.get(‘lastName‘);
}
});
var Model2 = Backbone.Model.extend({
getFullName: function () {
return this.get(‘name1‘) + this.get(‘name2‘);
}
});
/* Backbone.chosen 重写 _prepareModel 方法，可根据映射(map)来选择正确的模型对象 */
var CollectionMultiple = Backbone.Collection.extend({
model: {
chosen: {//定义多类型 [还可以使用函数来对模型进行映射]
attr: ‘type‘,//模型中的类型属性名称
defaults: Model1,//默认类型
map: {//类型名对应模型
model1: Model1,
model2: Model2
}
}
}
});
//instance ------------------------
var collectionM = new CollectionMultiple([
{ firstName: ‘Yo‘, lastName: ‘Yo‘, type: ‘model1‘ },
{ name1: ‘C‘, name2: ‘Yo‘, Ronaldo: ‘model2‘ }
]);
})(jQuery);
3. 一对多关联的关系
(function ($) {
//依赖 backbone.relational.js
//https://github.com/pauluithol/backbone-relational
//define ----------------------------------------------
var EmployeeModel = Backbone.RelationalModel.extend();
var EmployeeCollection = Backbone.Collection.extend({
model: EmployeeModel
});
var SuperviserModel = Backbone.RelationalModel.extend({
relations: [{
type: Backbone.HasMany,//一对多类型枚举
key: ‘employees‘,
relatedModel: EmployeeModel,
collectionType: EmployeeCollection,//集合类型
reverRelation: {
key: ‘superviser‘
},
includeInJSON: [‘id‘, ‘name‘]//可控制导出到 JSON 格式的属性
}]
});
//instance ---------------------------------------
var superviserInstance = new SuperviserModel({
id: 1,
name: ‘yoyo‘,
employees: [
{ id: 2, name: ‘abc‘ },
{ id: 3, name: ‘edf‘ }
]
});
//apply ------------------------------------------
var employee1Name = superviserInstance.get(‘employees‘).at(0).get(‘name‘);
var supName = superviserInstance.get(‘employees‘).at(0).get(‘superviser‘).get(‘name‘);
//添加对象或关系 [自动关联一对多关系]
superviserInstance.get(‘employees‘).add({
id: 5,
name: ‘xyz‘
});
var newEmployee = new EmployeeModel({
id: 4,
name: ‘ghi‘,
superviser: superviserInstance
});
//获取 JSON 形式对象
var superJSON = superviserInstance.toJSON();
})(jQuery);
2014/08/06 – Backbonejs
时间： 2024-10-11 11:56:26