Question

如何在集合提取中阻止模型的解析函数？

    $(function() {
    var Task = Backbone.Model.extend({
        url : function() {
                return this.urlRoot + this.id;
        },
        urlRoot: 'index.php?c=light&a=list_tasks_bb&ajax=true&task=',
        parse: function (response, options) {
            console.log(options);
            console.log(response);
            return response;
        }
    });

    var TaskList = Backbone.Collection.extend({
        model: Task,
        url: 'index.php?c=light&a=list_tasks_bb&ajax=true',

        initialize: function () {

        },
        parse: function (response, options) {
            return response.tasks;
        }
    });

    var Light = Backbone.Router.extend({
        el: $('#light'),
        routes: {
            "tasks/:id": "taskAction",
            "*page": "defaultAction",
        },

        initialize: function () {
            _this = this;
            this.tasks = new TaskList();
            this.users = new UserList();
        },

        taskAction: function(id) {
            this.task = new Task({id: id});
            $.when (
                this.task.fetch()
            ).then(function(zzz) {
                new TaskView({model: _this.task}).render();
            });
        },
        defaultAction: function(page) {
            $.when (
                this.tasks.fetch(),
                this.users.fetch()
            ).then (function() {
                new TaskListView({collection: _this.tasks}).render();
            });
        }
    });
});

我有一个模型和一个集合，我通过ajax fetch获得。我没有机会改变后端，所以任务列表的json结构是：

"contents": {},
"current": false,
"errorCode": 0,
"errorMessage": "",
"u": 4,
"tasks": [{
    "id": "12250",
    "t": "ZZZ",
    "cid": "24",
    "c": "2013-08-22 11:36:32",
    "dd": "02.09.2013",
    "sd": "02.09.2013",
    "pr": "300",
    "pid": "0",
    "atid": "1:4",
    "s": 0,
    "dl": ""
}, {
    "id": "12307",
    "t": "ZZZ",
    "cid": "42",
    "c": "2013-08-28 11:14:44",
    "dd": "05.09.2013",
    "sd": "28.08.2013",
    "pr": "200",
    "pid": "0",
    "atid": "1:4",
    "s": 0,
    "dl": ""
}, {
    "id": "12326",
    "t": "ZZZ",
    "cid": "2",
    "c": "2013-08-29 09:55:34",
    "dd": "31.08.2013",
    "sd": "29.08.2013",
    "pr": "200",
    "pid": "0",
    "atid": "1:4",
    "s": 0,
    "dl": ""
}],
"events": []

这就是我使用parse进行收集的原因。在这一步中，一切都很好。单个任务的JSON结构是：

"contents": {},
"current": false,
"errorCode": 0,
"errorMessage": "",
"u": 4,
"tasks": [{
    "id": "12250",
    "t": "ZZZZ",
    "cid": "24",
    "c": "2013-08-22 11:36:32",
    "dd": "02.09.2013",
    "sd": "02.09.2013",
    "pr": "300",
    "pid": "0",
    "atid": "1:4",
    "text": "XXXXX",
    "s": 0,
    "dl": ""
}],
"comments": [{
    "id": "48178",
    "text": "CCCC",
    "cid": "4",
    "con": "23.08.2013"
}],
"events": []

所以我需要在“task.fetch（）”之后再次解析获取单个任务。在我在模型中添加解析函数后，它工作正常，直到我开始获取集合，因为在收集解析后我已经有了正确的模型数据，但模型再次为每个模型解析回调。

我是否有正确的方法来解决此问题或更好的方法是尝试更改后端？

PS 当然，我可以这样做：

  if(response.tasks) {
    return response.tasks[0];
  } else {
    return response;
  }

但我认为这不是正确的解决方案。

Answer 1

当creating models for insertion in a collection时，Backbone将未来集合作为选项传递给模型构造函数，模型构造函数又将此选项转发给parse。您可以检查此属性并根据需要中止解析：

var Task  = Backbone.Model.extend({
    parse : function(response, options){
        if (options.collection) return response;
        return response.tasks[0];
    }
});
var TaskList = Backbone.Collection.extend({
    model: Task,
    parse : function(response){
        return response.tasks;
    }
});

演示http://jsfiddle.net/nikoshr/dfMgR/

Backbone - 在获取后不解析集合中的每个模型

1 个答案: