Ember.js quiz questions: save/delete hasMany data

Question

I'm building a quiz generator as my first Ember project, but I'm struggling. I've been able to create, edit and delete quizzes and save them to localstorage, but I'm having trouble saving/deleting quiz questions for each quiz.

I'm building it in Yeoman-Ember. I tried to add a demo to JSBin but it didn't work, so I've got a demo build here: http://test.richardwestenra.com/embertest/ and here's a zip containing the current state of the build: http://test.richardwestenra.com/embertest/dev.zip

Here's my combined-scripts.js file:

(function() {

var Quizmaker = window.Quizmaker = Ember.Application.create();

/* Order and include as you please. */


})();

(function() {

/* global $ */

Quizmaker.QuizzesController = Ember.ObjectController.extend({
});

Quizmaker.NewController = Ember.ObjectController.extend({
    content: {},
    quiztypes: ['Multiple choice', 'List', 'Either/or'],
    actions: {
        save: function(){
            var title = $('#title').val();
            var excerpt = $('#excerpt').val();
            var quiztype = $('#quiztype').val();
            var fullname = $('#fullname').val();
            var submittedOn = new Date();
            var store = this.get('store');
            if (Ember.isEmpty(title)) {
                window.alert('Please enter a title');
                return false;
            } else if (Ember.isEmpty(quiztype)) {
                window.alert('Please enter a quiz type');
                return false;
            }
            var quiz = store.createRecord('quiz',{
                quiztype : quiztype,
                fullname : fullname,
                title : title,
                excerpt : excerpt,
                submittedOn : submittedOn
            });
            quiz.save();
            this.transitionToRoute('index');
        },
        cancel: function(){
            this.transitionToRoute('index');
        },
        createQuestion: function(){
            window.alert('This doesn\'t work for new questions. I don\'t know why. It works for existing questions.');
            var store = this.get('store');
            var question = store.createRecord('question',{
                question : 'Test question ' + new Date()
            });
            var model = this.get('model');
            var questions = this.get('questions');
            questions.pushObject(question);
            model.set('questions', questions);
            model.save();
        }
    }
});


Quizmaker.QuizController = Ember.ObjectController.extend({
    quiztypes: ['Multiple choice', 'Checklist', 'Boolean'],
    actions: {
        edit: function(){ 
            this.transitionToRoute('quiz.edit');
            this.set('isEditing', true);
        },
        doneEditing: function(){
            var model = this.get('model');
            var title = $('#title').val();
            var excerpt = $('#excerpt').val();
            var quiztype = $('#quiztype').val();
            var fullname = $('#fullname').val();
            var questions = this.get('questions');
            if (Ember.isEmpty(title)) {
                window.alert('Please enter a title');
                return false;
            } else if (Ember.isEmpty(quiztype)) {
                window.alert('Please enter a quiz type');
                return false;
            } else {
                this.set('isEditing', false);
                model.set('title', title);
                model.set('excerpt', excerpt);
                model.set('quiztype', quiztype);
                model.set('fullname', fullname);
                model.set('questions', questions);
                model.save();
                this.transitionToRoute('quiz');
            }
        },
        cancel: function(){
            if (window.confirm('Are you sure you want to abandon your changes?')){
                this.set('isEditing', false);
                this.transitionToRoute('quiz');
            }
        },
        remove: function(){
            if (window.confirm('Are you sure you want to delete this quiz?')){
                var quiz = this.get('model');
                quiz.destroyRecord();
                this.transitionToRoute('index');
            }
        },
        createQuestion: function(){
            var store = this.get('store');
            var question = store.createRecord('question',{
                question : 'Test question ' + new Date()
            });
            var model = this.get('model');
            var questions = this.get('questions');
            questions.pushObject(question);
            model.set('questions', questions);
            model.save();
        }
    }
});

Quizmaker.QuestionsController = Ember.ArrayController.extend({
    needs: 'quiz',
    quiz: Ember.computed.alias("controllers.quiz"),
    actions: {
        createQuestion: function(){
            var store = this.get('store');
            var question = store.createRecord('question',{
                question : 'Test question ' + new Date()
            });
            var quiz = this.get('quiz');
            var questions = quiz.get('questions');
            questions.pushObject(question);
            console.log(question);
        },
        removeQuestion: function(id){
            var question = this.findProperty('id', id);
            this.removeObject(question);
        }
    }
});

})();

(function() {

Quizmaker.Store = DS.Store.extend();
// Quizmaker.ApplicationAdapter = DS.FixtureAdapter;
Quizmaker.ApplicationAdapter = DS.LSAdapter.extend({
    namespace: 'quizzes'
});

})();

(function() {

/* global Ember */
Quizmaker.Quiz = DS.Model.extend({
  title : DS.attr('string'),
  excerpt : DS.attr('string'),
  fullname : DS.attr('string'),
  quiztype : DS.attr('string'),
  questions: DS.hasMany('question', {async: true}), //  via http://stackoverflow.com/questions/22494140/in-ember-js-how-do-i-create-a-computed-property-that-references-first-item-in-pr
  questionsCount: function() {
        return this.get('questions.length');
    }.property('questions.@each'), // via http://stackoverflow.com/questions/16463958/how-to-use-multiple-models-with-a-single-route-in-emberjs-ember-data
  // firstQuestion: function() {
  //   return this.get('questions.firstObject');
  // }.property('questions.firstObject')
  submittedOn : DS.attr('date')
});

Quizmaker.Question = DS.Model.extend({
    quiz: DS.belongsTo('quiz'),
    question: DS.attr('string'),
    answers: DS.attr('string')
});

// delete below here if you do not want fixtures
Quizmaker.Quiz.FIXTURES = [
    {
        id: 0,
        title: 'Lorem ipsum dolor sit amet, consectetur adipiscing elit',
        excerpt: 'Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry\'s standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.',
        quiztype: 'Boolean',
        fullname: 'Full Name',
        submittedOn: null
    }
];
Quizmaker.Question.FIXTURES = [
    {
        id: 0,
        question: 'Test question Lorem ipsum dolor sit amet, consectetur adipiscing elit',
        quiz: 0,
        answers: [
            { answer: 'alpha', weight: 0 },
            { answer: 'beta', weight: 5 }
        ]
    }
];


})();

(function() {

Quizmaker.ApplicationRoute = Ember.Route.extend({
    model: function () {
        return this.get('store').findAll('quiz');
    }
});

Quizmaker.QuizzesRoute = Ember.Route.extend({
    model: function() {
        return this.get('store').find('quiz');
    }
});

Quizmaker.QuizRoute = Ember.Route.extend({
    model: function(params) {
        return this.get('store').find('quiz', params.quiz_id);
    }
});

Quizmaker.QuestionsRoute = Ember.Route.extend({
    controllerName: 'quiz',
    model: function() {
        return this.store.findAll('question');
    }
});

})();

(function() {

Quizmaker.QuizView = Ember.View.extend({
    keyDown: function(e) {
        var esc = 27;
        if(e.keyCode === esc){
            this.get('controller').send('cancel');
        }
    }
});

// Give the text fields one way value binding so they don't automatically update
Quizmaker.TextField = Ember.TextField.extend({
    valueBinding: Ember.Binding.oneWay('source')
});
Quizmaker.TextArea = Ember.TextArea.extend({
    valueBinding: Ember.Binding.oneWay('source')
});
Quizmaker.Select = Ember.Select.extend({
    valueBinding: Ember.Binding.oneWay('source')
});

})();

(function() {

Quizmaker.QuizzesView = Ember.View.extend({
});


})();

(function() {

Quizmaker.Router.map(function () {
    // Add your routes here
    this.resource('index',{path : '/'});
    this.resource('new' , {path : '/quiz/new'});
    this.resource('quizzes' , {path : '/quizzes'});
    this.resource('questions' , {path : '/questions'});

    this.resource('quiz', { path: '/quiz/:quiz_id' }, function(){
        this.route('edit', { path: '/edit' });
    });
});

})();

(function() {

/* global moment */
Ember.Handlebars.helper('format-date', function(date){
    return moment(date).fromNow();
});

})();

This is quiz.hbs:

{{#if isEditing}}
    <h1>Edit quiz</h1>
    {{partial "editform"}}
{{else}}
    <h1>{{title}}</h1>
    <h4>A <em style="text-transform: lowercase;">{{quiztype}}</em> quiz by {{fullname}} <small class="muted">{{format-date submittedOn}}</small></h4>
    <hr>
    <p class="lead">{{excerpt}}</p>
    <button type="submit" class="btn btn-default" {{action 'edit'}}>Edit</button>
    <button class="btn btn-danger pull-right" {{action 'remove'}}>Delete Quiz</button>
{{/if}}

This is _editform.hbs:

        <form class="form-horizontal" role="form">
        <div class="form-group">
            <label for="title" class="col-sm-2 control-label">Title</label>
            <div class="col-sm-10">
                {{!-- {{#view Quizmaker.TextInputView}}
                {{/view}} --}}
                {{!-- <input type="text" class="form-control" id="title" name="title" placeholder="Title of the quiz" required> --}}
                {{view Quizmaker.TextField type="text" class="form-control" id="title" name="title" sourceBinding="title" placeholder="Title of the quiz" required="required" }}
            </div>
        </div>
        <div class="form-group">
            <label for="excerpt" class="col-sm-2 control-label">Excerpt</label>
            <div class="col-sm-10">
                {{!-- <textarea class="form-control" id="excerpt" name="excerpt" placeholder="Short description of the quiz" required></textarea> --}}
                {{view Quizmaker.TextArea class="form-control" id="excerpt" name="excerpt" sourceBinding="excerpt" placeholder="Short description of the quiz" rows="3" required="required" }}
            </div>
        </div>
        <div class="form-group">
            <label for="fullname" class="col-sm-2 control-label">Author</label>
            <div class="col-sm-10">
                {{!-- <input type="text" class="form-control" id="fullname" name="fullname" placeholder="Enter your Full Name like Alan Smithee" required> --}}
                {{view Quizmaker.TextField type="text" class="form-control" id="fullname" name="fullname" sourceBinding="fullname" placeholder="Enter your full name, e.g. Alan Smithee" required="required" }}
            </div>
        </div>
        <div class="form-group">
            <label for="quiztype" class="col-sm-2 control-label">Quiz type</label>
            <div class="col-sm-10">
                {{view Quizmaker.Select id="quiztype" name="quiztype" class="form-control" viewName="select" content=quiztypes prompt="Pick a type:" sourceBinding="quiztype"}}
            </div>
        </div>
        <div class="form-group">
            <label for="quiztype" class="col-sm-2 control-label">Questions ({{questionsCount}})</label>
            <div class="col-sm-10">
                {{render "questions" questions}}
            </div>
        </div>
        <div class="form-group">
            <div class="col-sm-offset-2 col-sm-10">
                {{#if isEditing}}
                    <button type="submit" class="btn btn-success" {{action 'doneEditing'}}>Save</button>
                    <button class="btn btn-warning pull-right" {{action 'cancel'}}>Cancel</button>
                {{else}}
                    <button type="submit" class="btn btn-success" {{action 'save'}}>Save</button>
                    <button class="btn btn-warning pull-right" {{action 'cancel'}}>Cancel</button>
                {{/if}}
            </div>
        </div>
    </form>

And this is questions.hbs:

    <p><button class="btn btn-info btn-sm" {{action 'createQuestion'}}><span class="glyphicon glyphicon-plus"></span> Add new question</button></p>
<table class="table table-striped">
    {{#each model}}
        <tr>
            <td>{{this.question}}</td>
            <td>{{this.id}}</td>
            <td><button class="btn btn-danger btn-xs pull-right" {{action 'removeQuestion' id}}>Delete</button></td>
        </tr>
    {{/each}}
</table>

If anyone can point out ways I can improve it, I'd be very grateful. I've tried implementing every method I can find to get it to save or delete hasMany data but it always throws different errors and I'm not really sure where to proceed from here.

I'm also trying to figure out how to toggle the isEditing state depending on whether the /edit route is displayed (instead of having it activated by an action).

Answer 1

let's break this down into two different items, last to first.

The trick in showing the edit mode versus view mode is to take advantage of the free index route which is rendered at the root of every resource.

You can change your quiz template to be an outlet

{{outlet}}

and create a quiz/index template which originally held your quiz data. This template will only show up when you are at /quiz/123 when you navigate to /quiz/123/edit the index template will be replaced with the edit template. (You'll probably want to return the model from the resource to both routes using modelFor).

App.Router.map(function() {
  this.resource('foo', {path:'/'},function(){
    this.route('edit');
  })
});

App.FooRoute = Em.Route.extend({
  model: function() {
    return [{color:'red'}, {color:'yellow'},{color: 'blue'}];
  }
});

App.FooIndexRoute = Ember.Route.extend({
  model: function() {
    return this.modelFor('foo');
  }
});


App.FooEditRoute = Ember.Route.extend({
  model: function() {
    return this.modelFor('foo');
  }
});

http://emberjs.jsbin.com/lodeviyu/1/edit

In Ember Data if you have two record types that each have a relation to each other:

App.FooRecord = DS.Record.extend({
  bars: DS.hasMany('bar')
});

App.BarRecord = DS.Record.extend({
  foo: DS.belongsTo('foo')
});

Let's create and associate two records:

var foo = store.create('foo');

var bar = store.create('bar');

foo.get('bars').pushObject(bar);

bar.set('foo', foo);

Now let's save, and see what Ember Data will do:

foo.save();
// json sent
{
  foo: {}
}
// responds with id 1

bar.save();
// json sent
{
  bar: {
    foo: 1
  }
}

Ember Data chooses not to save the hasMany relationship if their is a correlated belongsTo from a different model type.

https://github.com/emberjs/data/commit/7f752ad15eb9b9454e3da3f4e0b8c487cdc70ff0#commitcomment-6078838