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How to render a collection with a Marionette's ItemView?

I'm trying to render the response from an API (JSON) with Backbone.Marionette.ItemView. Not sure why it is not working.
I'm using marionette v2.4.7 (on purpose);
Here is the handlebars template:
<script id="feed-post" type="text/x-handlebars-template">
{{#each posts}}
<img src="{{author.image_url}}" alt="">
<p>{{author.name}}</p>
<span>TODO TIMESTAMP</span>
<p>{{body}}</br>{{topic_type}}</p>
{{/each}}
</script>
Here is my full app.js (all Backbone logic in this file);
// Model
var Post = Backbone.Model.extend({
defaults: {
authorPic: 'Unknown',
authorName: 'Unknown',
timestamp: 'Unknown',
body: 'Not available',
comments: '0'
}
});
// Collection
var Posts = Backbone.Collection.extend({
model: Post,
url: 'http://localhost:4321/blogposts',
initialize: function(){
this.fetch();
}
});
// View
var PostView = Marionette.ItemView.extend({
el: '#content',
template: Handlebars.compile($("#feed-post").html()),
});
//Config
var chunkPosts = new Posts();
var myview = new PostView({collection: chunkPosts});
Also, I tried to console.log the view and it looks like the models are in there.

This answer is tailored to Marionette v2.4.7. LayoutView and ItemView were merged and renamed to View back in v3.0.0.
From the doc on ItemView:
Rendering this view will convert the someCollection collection in to
the items array for your template to use.
You are using posts in your template while the doc says it will be called items.
As a reference, here's the exact code doing that in the ItemView source:
// Serialize the model or collection for the view. If a model is
// found, the view's `serializeModel` is called. If a collection is found,
// each model in the collection is serialized by calling
// the view's `serializeCollection` and put into an `items` array in
// the resulting data. If both are found, defaults to the model.
// You can override the `serializeData` method in your own view definition,
// to provide custom serialization for your view's data.
serializeData: function() {
if (!this.model && !this.collection) {
return {};
}
var args = [this.model || this.collection];
if (arguments.length) {
args.push.apply(args, arguments);
}
if (this.model) {
return this.serializeModel.apply(this, args);
} else {
return {
items: this.serializeCollection.apply(this, args)
};
}
},
The last lines show that for a collection, a new object with items as the only attribute is returned.
It's mentioned that you can override the serializeData function, more information and examples are available in the doc.
You still need to call render on the view and since the collection's fetch is async, you won't have items out of the box so you should wire a listener.
First, don't fetch in the initialize of a collection, it makes the collection pretty much useless for any other use-case.
var Posts = Backbone.Collection.extend({
model: Post,
url: 'http://localhost:4321/blogposts',
});
Listen for the collection sync event, then fetch within the view instead.
var PostView = Marionette.ItemView.extend({
el: '#content',
template: Handlebars.compile($('#feed-post').html()),
initialize: function () {
this.listenTo(this.collection, 'sync', this.render);
this.collection.fetch();
},
});
Marionette even offers collectionEvents:
var PostView = Marionette.ItemView.extend({
// ...snip...
collectionEvents: {
"sync": "render"
}
// ...snip...
});

Backbone view/template fails to load from REST

I have properly coded a simple REST api and several backbone models. My parent model is called Topic and child model called Questions.
I'm trying to call a get method on the REST api and display the received Topic object to the user in a presentable manner. I am receiving the json (can be seen in the network tab on Chrome), but it is not getting sent to the view correctly.
Model:
var Topic = Backbone.Model.extend({
urlRoot: ROOT + '/topic',
idAttribute: 'topicId',
initialize: function () {
this.questions = new Questions([], {parent: this});
},
toJSON: function () {
var json = Backbone.Model.prototype.toJSON.call(this);
json.questions = this.questions.toJSON();
return json;
}
});
var Topics = Backbone.Collection.extend({
model: Topic,
url: ROOT + 'topic',
parse: function (response) {
return response.results;
}
})
REST URL:
http://localhost/Project/index.php/rest/resource/topic/
Backbone View: This is where I think the error is...(console log below prints an empty object)
var TopicListView = Backbone.View.extend({
el: '.page',
render: function () {
var that = this;
var topics = new Topics();
topics.fetch({
success: function (topics) {
console.log(topics);
var template = _.template($('#topic-list-template').html(), {topics: topics.models});
that.$el.html(template);
}
})
}
});
Using the above functions:
var topic = new Topic();
topic.fetch();
topicListView = new TopicListView();
var Router = Backbone.Router.extend({
routes: {
"": "home"
}
});
var router = new Router;
// render topic list for 'home'
router.on('route:home', function () {
topicListView.render();
});
Edit: Solution: Overriding the parse function in the collection proved to be the error. I wonder why...

The argument topics in your success handler is shadowing the variable topics.
The argument contains the parsed JSON response, not the Backbone Collection. You don't need that, so you can remove the argument.
The reference to topics will now be to your Collection, so topics.models will have the value you expect.
topics.fetch({
success: function () { // argument removed here so `topics` is no longer shadowed
var template = _.template($('#topic-list-template').html(), { topics: topics.models });
that.$el.html(template);
}
})

EmberJS: How to load multiple models on the same route?

While I am not new to web development, I am quite new to to client-side MVC frameworks. I did some research and decided to give it a go with EmberJS. I went through the TodoMVC guide and it made sense to me...
I have setup a very basic app; index route, two models and one template. I have a server-side php script running that returns some db rows.
One thing that is very confusing me is how to load multiple models on the same route. I have read some information about using a setupController but I am still unclear. In my template I have two tables that I am trying to load with unrelated db rows. In a more traditional web app I would have just issued to sql statements and looped over them to fill the rows. I am having difficulty translating this concept to EmberJS.
How do I load multiple models of unrelated data on the same route?
I am using the latest Ember and Ember Data libs.
Update
although the first answer gives a method for handling it, the second answer explains when it's appropriate and the different methods for when it isn't appropriate.

BEWARE:
You want to be careful about whether or not returning multiple models in your model hook is appropriate. Ask yourself this simple question:
Does my route load dynamic data based on the url using a slug :id? i.e.
this.resource('foo', {path: ':id'});
If you answered yes
Do not attempt to load multiple models from the model hook in that route!!! The reason lies in the way Ember handles linking to routes. If you provide a model when linking to that route ({{link-to 'foo' model}}, transitionTo('foo', model)) it will skip the model hook and use the supplied model. This is probably problematic since you expected multiple models, but only one model would be delivered. Here's an alternative:
Do it in setupController/afterModel
App.IndexRoute = Ember.Route.extend({
model: function(params) {
return $.getJSON('/books/' + params.id);
},
setupController: function(controller, model){
this._super(controller,model);
controller.set('model2', {bird:'is the word'});
}
});
Example: http://emberjs.jsbin.com/cibujahuju/1/edit
If you need it to block the transition (like the model hook does) return a promise from the afterModel hook. You will need to manually keep track of the results from that hook and hook them up to your controller.
App.IndexRoute = Ember.Route.extend({
model: function(params) {
return $.getJSON('/books/' + params.id);
},
afterModel: function(){
var self = this;
return $.getJSON('/authors').then(function(result){
self.set('authors', result);
});
},
setupController: function(controller, model){
this._super(controller,model);
controller.set('authors', this.get('authors'));
}
});
Example: http://emberjs.jsbin.com/diqotehomu/1/edit
If you answered no
Go ahead, let's return multiple models from the route's model hook:
App.IndexRoute = Ember.Route.extend({
model: function() {
return {
model1: ['red', 'yellow', 'blue'],
model2: ['green', 'purple', 'white']
};
}
});
Example: http://emberjs.jsbin.com/tuvozuwa/1/edit
If it's something that needs to be waited on (such as a call to the server, some sort of promise)
App.IndexRoute = Ember.Route.extend({
model: function() {
return Ember.RSVP.hash({
model1: promise1,
model2: promise2
});
}
});
Example: http://emberjs.jsbin.com/xucepamezu/1/edit
In the case of Ember Data
App.IndexRoute = Ember.Route.extend({
var store = this.store;
model: function() {
return Ember.RSVP.hash({
cats: store.find('cat'),
dogs: store.find('dog')
});
}
});
Example: http://emberjs.jsbin.com/pekohijaku/1/edit
If one is a promise, and the other isn't, it's all good, RSVP will gladly just use that value
App.IndexRoute = Ember.Route.extend({
var store = this.store;
model: function() {
return Ember.RSVP.hash({
cats: store.find('cat'),
dogs: ['pluto', 'mickey']
});
}
});
Example: http://emberjs.jsbin.com/coxexubuwi/1/edit
Mix and match and have fun!
App.IndexRoute = Ember.Route.extend({
var store = this.store;
model: function() {
return Ember.RSVP.hash({
cats: store.find('cat'),
dogs: Ember.RSVP.Promise.cast(['pluto', 'mickey']),
weather: $.getJSON('weather')
});
},
setupController: function(controller, model){
this._super(controller, model);
controller.set('favoritePuppy', model.dogs[0]);
}
});
Example: http://emberjs.jsbin.com/joraruxuca/1/edit

NOTE: for Ember 3.16+ apps, here is the same code, but with updated syntax / patterns: https://stackoverflow.com/a/62500918/356849
The below is for Ember < 3.16, even though the code would work as 3.16+ as fully backwards compatible, but it's not always fun to write older code.
You can use the Ember.RSVP.hash to load several models:
app/routes/index.js
import Ember from 'ember';
export default Ember.Route.extend({
model() {
return Ember.RSVP.hash({
people: this.store.findAll('person'),
companies: this.store.findAll('company')
});
},
setupController(controller, model) {
this._super(...arguments);
Ember.set(controller, 'people', model.people);
Ember.set(controller, 'companies', model.companies);
}
});
And in your template you can refer to people and companies to get the loaded data:
app/templates/index.js
<h2>People:</h2>
<ul>
{{#each people as |person|}}
<li>{{person.name}}</li>
{{/each}}
</ul>
<h2>Companies:</h2>
<ul>
{{#each companies as |company|}}
<li>{{company.name}}</li>
{{/each}}
</ul>
This is a Twiddle with this sample: https://ember-twiddle.com/c88ce3440ab6201b8d58

Taking the accepted answer, and updating it for Ember 3.16+
app/routes/index.js
import Route from '#ember/routing/route';
import { inject as service } from '#ember/service';
export default class IndexRoute extends Route {
#service store;
async model() {
let [people, companies] = await Promise.all([
this.store.findAll('person'),
this.store.findAll('company'),
]);
return { people, companies };
}
}
Note, it's recommended to not use setupController to setup aliases, as it obfuscates where data is coming from and how it flows from route to template.
So in your template, you can do:
<h2>People:</h2>
<ul>
{{#each #model.people as |person|}}
<li>{{person.name}}</li>
{{/each}}
</ul>
<h2>Companies:</h2>
<ul>
{{#each #model.companies as |company|}}
<li>{{company.name}}</li>
{{/each}}
</ul>

I use something like the answer that Marcio provided but it looks something like this:
var products = Ember.$.ajax({
url: api + 'companies/' + id +'/products',
dataType: 'jsonp',
type: 'POST'
}).then(function(data) {
return data;
});
var clients = Ember.$.ajax({
url: api + 'clients',
dataType: 'jsonp',
type: 'POST'
}).then(function(data) {
return data;
});
var updates = Ember.$.ajax({
url: api + 'companies/' + id + '/updates',
dataType: 'jsonp',
type: 'POST'
}).then(function(data) {
return data;
});
var promises = {
products: products,
clients: clients,
updates: updates
};
return Ember.RSVP.hash(promises).then(function(data) {
return data;
});

If you use Ember Data, it gets even simpler for unrelated models:
import Ember from 'ember';
import DS from 'ember-data';
export default Ember.Route.extend({
setupController: function(controller, model) {
this._super(controller,model);
var model2 = DS.PromiseArray.create({
promise: this.store.find('model2')
});
model2.then(function() {
controller.set('model2', model2)
});
}
});
If you only want to retrieve an object's property for model2, use DS.PromiseObject instead of DS.PromiseArray:
import Ember from 'ember';
import DS from 'ember-data';
export default Ember.Route.extend({
setupController: function(controller, model) {
this._super(controller,model);
var model2 = DS.PromiseObject.create({
promise: this.store.find('model2')
});
model2.then(function() {
controller.set('model2', model2.get('value'))
});
}
});

The latest version of JSON-API as implemented in Ember Data v1.13 supports bundling of different resources in the same request very well, if you don't mind modifying your API endpoints.
In my case, I have a session endpoint. The session relates to a user record, and the user record relates to various models that I always want loaded at all times. It's pretty nice for it all to come in with the one request.
One caveat per the spec is that all of the entities you return should be linked somehow to the primary entity being received. I believe that ember-data will only traverse the explicit relationships when normalizing the JSON.
For other cases, I'm now electing to defer loading of additional models until the page is already loaded, i.e. for separate panels of data or whatever, so at least the page is rendered as quickly as possible. Doing this there's some loss/change with the "automatic" error loading state to be considered.

Backbone Collection not getting models

Basically, I'm trying to send a GET request to my Node server, so that I can get back blog posts to create links. I do a collection.fetch, which successful completes the GET request (the Node server logs that it's sending the right objects). The model successfully parses the right data, but when I try to use the collection, it says that it's empty. Here's the code:
var mdm = mdm || {};
// MODEL
mdm.Post = Backbone.Model.extend({
parse: function( response ) {
response.id = response._id;
console.log(response); // logs the two documents
return response;
}
});
// COLLECTION
mdm.Posts = Backbone.Collection.extend({
model: mdm.Post,
url: '/api/posts'
});
// MODEL VIEW
mdm.LinkView = Backbone.View.extend({
template: _.template( $('#link_template').html() ),
render: function() {
this.$el.html( this.template( this.model.toJSON() ));
return this;
}
});
// COLLECTION VIEW
mdm.LinksView = Backbone.View.extend({
el: '#link_list',
initialize: function() {
this.collection = new mdm.Posts();
this.collection.fetch({reset: true});
// makes the request properly, but collection is empty
this.render();
// never gets called because the collection is empty
console.log(this.collection.length);
// logs a length of 0
},
render: function() {
// renders collection
}
});
$(function() {
new mdm.LinksView();
});
The data is being sent and is parsed in the models, so I'm not sure what the collection ends up being empty. Any help would be greatly appreciated.

The most likely reason you are not seeing the models in your view is because the render is happening before the asynchronous fetch is complete.
Something like below would work better:
mdm.LinksView = Backbone.View.extend({
el: '#link_list',
initialize: function() {
this.collection = new mdm.Posts();
this.listenTo(this.collection, 'reset', this.render);
this.collection.fetch({reset: true});
}
The above code sets a listener for the reset event on the collection and executes the render function when that happens.
Also, you could passing in success and error handlers into fetch and call the render function manually as well.
this.collection.fetch({
success: _.bind(function() {
this.render(); }, this)
});
Hope this helps!

Per #fbynite's comment, the problem was related to fetch being asynchronous. I made the following changes to the collection view, and it did the trick:
initialize: function() {
var self = this;
this.collection = new mdm.Posts();
this.collection.fetch({reset: true,
success: function() {
self.render();
console.log(self.collection.length);
}
});
},
The code is a modification from a Backbone tutorial, so other users may encounter a similar problem. http://addyosmani.github.io/backbone-fundamentals/#exercise-2-book-library---your-first-restful-backbone.js-app

Backbone reset a collection on fetch

This is my problem:
I have a container view that holds a collection.
On page load I get some models, populate this collection with them, then render the models
I fire and event
When this event fires, I want to make a call to my api (which returns models based on input parameters)
I then want to remove all existing models from the collection, repopulate with my new models, and then render the models
This is how I set up my model/collection/view
var someModel = Backbone.Model.extend({});
var someCollection = Backbone.Collection.extend({
model: someModel,
url: "api/someapi"
});
var someView = Backbone.View.extend({
events: {
"click #refresh": "refreshCollection"
},
initialize: function () {
this.collection.bind("reset", this.render, this);
},
render: function () {
// render stuff
},
refreshCollection: function (e) {
this.collection.fetch({data: {someParam: someValue});
this.render();
}
});
var app = function (models) {
this.start = function () {
this.models = new someCollection();
this.view = new someView({collection: this.models});
this.view.reset(models);
};
};
My point of interest is here:
refreshCollection: function (e) {
this.collection.fetch({data: {someParam: someValue});
this.render();
}
I pass in some paramaters, and my api returns a json array of models. I want to get rid of all existing models in the collection, and put all of my returned models into the collection, then update the view (with render())
I understand this is possible with collection.set, or collection.reset. Both of these take in an array of models. I don't have an array of models to pass in.
I tried:
this.collection.fetch({
data: {someParam: someValue},
success: function (response) {
doSomethingWith(response.models)
}
});
But I don't know what to do with the models when I get them.
Any pushed in the right direction would be appreciated!

From the fine manual:
fetch collection.fetch([options])
[...] When the model data returns from the server, it uses set to (intelligently) merge the fetched models, unless you pass {reset: true}, in which case the collection will be (efficiently) reset.
So you just need to include reset: true in the options and fetch will call reset to replace the collection's contents with the fetched models:
this.collection.fetch({
data: { ... },
reset: true
});