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我正在做一个测验。我正在从 json 文件中加载问题。这些模型有一个“使用：”属性。我正在按使用过滤集合并提取 ID，然后我得到问题的随机 ID，并在回答后将 use 设置为 false。这样，用户将以随机顺序完成所有问题，没有重复。我想跟踪每个用户使用过的问题，并在他们完成所有问题后重置问题库。

我正在使用backbone.dualstorage，它工作了一次，然后我尝试通过遍历每个模型并销毁它来重置集合。现在我似乎无法用模型重新填充本地集合，因为远程模型具有与被破坏模型 ID 相同的 ID。

如何再次将远程集合中的所有模型重新添加到 localStorage？ 

//Question collection 
var PlayCollection = Backbone.Collection.extend({
    model: PlayModel,
    url: "https://raw.githubusercontent.com/robertocarroll/barjeel-app/master/app/data/questions.json",

//when I set remote it works without local at all
//remote: function () {return true;}
});

//define new question collection
var newCollection = new PlayCollection();

// load data
newCollection.fetch({
    success: function (newCollection, response, options) {
        console.log("fetch questions success");

        //this shows all the question IDs which I destroyed
        console.log(newCollection.destroyedModelIds());

        //this is empty 
        console.log(newCollection.dirtyModels());

    }
});

function getQuestion() {

    var theQuestions = newCollection.dirtyModels()[0].collection;

    //get the IDs of all questions which haven't been used    
    var questions = theQuestions.chain()
        .filter(function (m) {
        return m.get('use')
    })
        .pluck('id')
        .value();

    console.log(questions);

    if (questions.length > 0) {
        // get random ID from question ID array     
        var rand = questions[_.random(questions.length - 1)];

        console.log('chosen ID value: ' + rand);

        //get a model from a collection, specified by ID     
        var currentQuestion = theQuestions.get(rand);
        console.log(currentQuestion);

        //set the status of that question to used
        currentQuestion.set("use", false);
    }
    //if there's not more questions
    else {
        console.log("No more questions");

        //delete models in local 
        _.chain(newCollection.models).clone().each(function (model) {
            console.log('deleting model ' + model.id);
            model.destroy();
        });
    }
}

这是小提琴：http: //jsfiddle.net/robertocarroll/10xqvk18/10/

谢谢！

4

1 回答 1

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原来backbone.dualstorage 是矫枉过正。我直接访问了 localStorage：

//model for questions
PlayModel = Backbone.Model.extend({});

//model for which questions to use
PlayGameQuestionCount = Backbone.Model.extend({
 defaults: {
   "use": true
 }
});

//Question collection 
var PlayCollection = Backbone.Collection.extend({
 model: PlayModel,
 url: "https://raw.githubusercontent.com/robertocarroll/barjeel-app/master/app/data/questions.json"
});

//define new question collection
var newCollection = new PlayCollection();

function fetchQuestions() {
// load data
 newCollection.fetch({
    success: function (newCollection, response, options) {
        console.log("fetch questions success");
        //add data to local storage
        localStorage.setItem('questions', JSON.stringify(newCollection.toJSON()));

    }

});
}


function getQuestion() {

var newLocalCollection = new PlayCollection(JSON.parse(localStorage.getItem('questions')));
console.log(newLocalCollection);

//get the IDs of all questions which haven't been used    
var questions = newLocalCollection.chain()
    .filter(function (m) {
    return m.get('use')
})
    .pluck('id')
    .value();

console.log(questions);

if (questions.length > 0) {
    // get random ID from question ID array     
    var rand = questions[_.random(questions.length - 1)];

    console.log('chosen ID value: ' + rand);

    //get a model from a collection, specified by ID     
    var currentQuestion = newLocalCollection.get(rand);
    console.log(currentQuestion);

    //set the status of that question to used
    currentQuestion.set("use", false);
    localStorage.setItem('questions', JSON.stringify(newLocalCollection.toJSON()));

}
//if there's not more questions
else {
    console.log("No more questions");

    //delete models in local 
    fetchQuestions();
    }
}

//function to fire the questions
$(document).ready(function () {
$("#btnSave").click(

function () {
    getQuestion();
});
});

这是小提琴：http: //jsfiddle.net/hcqse7j4/3/

于 2015-07-09T11:30:37.260 回答