如何使用$.when.与Backbone一起应用.集合或模型

Question

下面的代码是保证所有主干的小函数。收集/模型获取操作。我现在面临的唯一问题是deferred.resolve你可以看到Models实际上是一个数组

fetchData: function(Models) {
    var deferred = $.Deferred();
    var xhr = $.when.apply(this, Models).done(function(data, textStatus, jqXHR) {
        deferred.resolve(Models, data, textStatus, jqXHR);
    }).fail(deferred.reject);
    var promise = deferred.promise();
    //promise.abort = _.bind(xhr.abort, xhr);
    return promise;
} 

这样做的目的是为了满足简单的for循环操作，每个循环都有自己的fetch操作。

示例call fetchData:

var param = = [{
    ipid: 44,
    measure: "cumec"
}, {
    ipid: 45,
    measure: "meter"
}, {
    ipid: 46,
    measure: "milimeter"
} {
    ipid: 47,
    measure: "cumec"
}];
var ajax_calls = [];
var _this = this;
var complete = _.after(param.length, function() {
    _this.fetchData(ajax_calls).done(performanotherfunction);
});
_.each(param, function(value, key) {
    var data = new Collection();
    data.id = value.ipid;
    ajax_calls.push(data.fetch({
        success: function(model) {
            console.log(model.get('res_ipid'));
        }
    }));
    complete()
}, this);

我预计fetchData将按照ipid的顺序返回Collection/Model。但是控制台的结果总是显示res_ipid not in order，因为这取决于fetch的竞争条件。

Answer 1

我觉得你把事情复杂化了。而不是:

var complete = _.after(param.length, function() {
    _this.fetchData(ajax_calls).done(performanotherfunction);
});
_.each(param, function(value, key) {
    var data = new Collection();
    data.id = value.ipid;
    ajax_calls.push(data.fetch({
        success: function(model) {
            console.log(model.get('res_ipid'));
        }
    }));
    complete()
}, this);

你应该能够这样做:

var promises = _.map(param, function(value, key) {
    var data = new Collection();
    data.id = value.ipid;
    return data.fetch({
        success: function(model) {
            console.log(model.get('res_ipid'));
        }
    });
});
$.when.apply($, promises).done(performanotherfunction);