I'm trying to follow a screencast on how to return a result from a database using Backbone.js and REST. My RESTful service (at least I think it's RESTful -- REST is new to me) is serving up JSON data like you would want. Everything appears to work fine until the last step when I try to access the data using at(). Here is my code.
This is my Backbone:
(function() {
window.App = {
Models: {},
Collections: {},
Views: {},
Router: {}
};
window.template = function(id) {
return _.template( $('#' + id).html());
};
var vent = _.extend({}, Backbone.Events);
App.Router = Backbone.Router.extend({
routes: {
'' : 'index',
'*other' : 'other'
},
index: function() {
},
other: function() {
}
});
App.Models.Main = Backbone.Model.extend({
defaults : {
FName: ''
}
});
App.Collections.Mains = Backbone.Collection.extend({
model: App.Models.Main,
url: '../leads/main_contact'
});
new App.Router;
Backbone.history.start();
})();
In the Firebug console, which is what's used in Jeffrey Way's screencast, I type the following:
mains = new App.Collections.Mains();
mains.fetch();
mains.toJSON();
That works fine. I can use Firebug to see that there is the proper data there. Here is my result:
[Object { id="1023", timestamp="2012-05-16 08:09:30", FName="Eulàlia", more...},...
But when I try to access the object with the id of 1023, I get "undefined." I do this:
mains.at(1023).get('FName');
What am I doing wrong?
the at method retrieves an element at a specific index in the collection.
So if you want to get the element at position 1023, you need 1023 items in your collection. Which you probally don't have.
The id that you have and set to 1023 has nothing to do with index in that collection.
Related
i'm trying to connect model and collection using parse.com but i'm confused. I'm tring to fetch by collection using backbone and javascript api parse.com but compare this error:POST https://api.parse.com/1/classes 404 (Not Found).
Model:
var Person = Backbone.Model.extend({
defaults:{
},
initialize:function(){
console.log("inperson");
this.validate();
this.send();
},
validate:function(){
console.log("validate");
},
send:function(){
var user = new Parse.User();
user.set("username", this.get("username"));
user.set("password", this.get("password"));
user.set("email", this.get("email"));
user.signUp(null, {
success: function(user) {
// Hooray! Let them use the app now.
},
error: function(user, error) {
// Show the error message somewhere and let the user try again.
alert("Error: " + error.code + " " + error.message);
}
});
}
});
return Person;
});
Collection:
var Usercollection = Parse.Collection.extend({
model:Person,
initialize:function(){
}
});
return Usercollection;
});
and finally the view that call the colletion and fetch:
var HomeView = Backbone.View.extend({
template: Handlebars.compile(template),
events: {
},
initialize: function() {
console.log("inhomeview");
var amici = new Usercollection();
amici.fetch({
success: function(collection) {
amici.each(function(object) {
console.warn(object);
});
},
error: function(amici, error) {
// The collection could not be retrieved.
}
});
},
render: function() {
}
});
return HomeView;
});
Cant you just swap the backbone collection and model to Parse's ones? (You only used the Parse type of the collection, not the model!)
Try switch that Backbone model to a Parse.Object .
Step by step below:
First of all Lets create a new app on Parse.com, mine is called FunkyAppartments.
Insert the script tag for loading Parse javascript lib into index.html or whathever:
<script src="http://www.parsecdn.com/js/parse-1.5.0.min.js"></script>
Switch the backbone model and collection to use parse types instead (and rename the fetch method if you have extended backbones, since we do not want to overide the one of parse):
//var Appartment = Backbone.Model.extend(); Backbone wo. Parse.com
var Appartment = Parse.Object.extend("Appartment");
//var Appartments = Backbone.Collection.extend({ Backbone wo. Parse.com
var Appartments = Parse.Collection.extend({
model: Appartment,
loadAppartments: function(callback){
debugger;
this.query = new Parse.Query(Appartment);
this.fetch();
}
});
I added a debugger tag in the load appartments so that developer tools breaks in the middle of the controller, here I have access to the Appartment private type of the controller, hence i can store some data on the parse server and verify by pasting the below in the developer tools console.
var testAppartment = new Appartment();
testAppartment.save({name: "foobars"}).then(function(object) {
alert("yay! it worked");
});
Yei, the data shows up in the parse.com UI for the app we just added there. And more importantly it shows up in our frontend. That was easy!
UPDATE: PROBLEMS W BACKBONE 1.2.1, MARIONETTE 2.4.2, UNDERSCORE 1.8.3
I noticed that I actually had been using old versions of marionette, backbone and underscore.js. An initial update appeared to break the application.
After some research i found that it was the parse part that did not return objects that would successfully render. Hence I changed the collection type back to an extension of: Backbone.collection instead of Parse.collection.
I also had to override the query method, since the objects would not save on the correct id, updating an object resulted in a new object being added instead of an old one being updated.
var Apartment = Parse.Object.extend('Appartment');
var Apartments = Backbone.Collection.extend({
model: Apartment,
query: new Parse.Query(Apartment),
initialize: function(){
MyApp.vent.on('search:param', function(param){self.search(param); });
var self = this;
this.query.find({
success: function(results){
self.reset();
results.forEach(function(result){
result.attributes.id__ = result.id
var ap = new Apartment(result.attributes);
self.add(ap);
});
}
});
}
});
I added an attribute: id__ to hold the parse id (naming it just id did not work since it backbone interfered with it, making it disappear).
Finally in saving the model to parse i utilized id__ as id in the save call:
var ApartmentEditView = Backbone.Marionette.ItemView.extend({
template: "#apartment-edit-template",
className: "apartmentDetail",
events: {
"click .store": "storeEdit",
"click .close": "closeEdit"
},
storeEdit: function(){
var priceNum = Number($('#price_field').val().replace(/\s/g, ''));
this.model.set({
id: this.model.attributes.id__,
name:$('#name_field').val(),
price:priceNum,
description:$('#desc_field').val(),
url:$('#url_field').val()
});
this.model.save();
this.closeEdit();
},
closeEdit: function(){
var detailView = new ApartmentDetailView({model: this.model});
MyApp.Subletting.layout.details.show(detailView);
}
});
Now the object is updated correctly in the database.
I'm trying to return JSON output from a Laravel route. Here's my route:
Route::get('main-contact-count', function() {
$mc = MainContact::where('flag', '=', '1')->count();
return Response::json(['count' => $mc]);
});
If I look at the response tab in Firebug, I'm getting back:
{"count":9}
The JSON encoding is missing the square brackets. This JSON is different than the JSON Laravel returns from a resourceful controller. It has the square brackets. Backbone parses it fine. Backbone doesn't parse the above JSON correctly. If you look at the length and models when you console.log a collection, they're both zero. You can, however, drill down into the object and you can find a count property set to 9.
How do I get the correct JSON out of Laravel?
Just for kicks and giggles, I'm posting my Backbone, in case I'm doing something hinky there:
App.Collections.Count = Backbone.Collection.extend({
model: App.Models.Count,
initialize: function(models, options) {
this.fetch({
success: function(data, options) {
// console.log(data.models);
}
});
if (options) {
this.url = this.url || options.url;
}
}
});
App.Views.Count = Backbone.View.extend({
tagName: 'span',
className: 'leadCount',
template: _.template($('#contactCount').html()),
initialize: function() {
},
render: function() {
this.$el.html(this.template(this.collection.toJSON()));
return this;
}
});
And in my route:
var mc = new (App.Collections.Count.extend({ url: 'main-contact-count' }))();
var mcv = new (App.Views.Count.extend({ collection: mc }))();
The JSON response sent by your service is a single JSON object ({...}) Your collection is not able to parse it because it expects an array of JSON objects ([{...}, {...}]).
If I've understood your code correctly, /main-contact-count is a specialized service whose function is to return and single datum: a count of contacts. If this is the case, Backbone.Collection may not be the correct solution. Collections are meant for... well, collections of things.
You should use just a model instead:
App.Models.Count = Backbone.Model.extend({
url:'main-contact-count'
});
var countModel = new App.Models.Count();
countModel.fetch({success: function(model, resp) {
var count = model.get('count');
});
Or even better, forego Backbone altogether and just fetch the data using jQuery:
$.getJSON('main-contact-count', function(response) {
var count = response.count;
});
try:
return Response::json(array(array('count' => $mc));
i try to fetch a record of a rails-api (same host) into my backbone collection. i have the following code:
// Models
App.GeeksModel = Backbone.Model.extend({
urlRoot: "/geeks",
idAttribute: "id"
});
// Collections
App.GeeksCollection = Backbone.Collection.extend({
url: "/geeks",
model: App.GeeksModel
});
in my router i have the following
// Router
App.GeekRouter = Backbone.Router.extend({
routes: {
"": "index"
},
initialize: function() {
console.log("router - init");
},
index: function() {
console.log("route - index");
var geekCollection = new App.GeeksCollection();
var mapView = new App.GeeksMapView({ el: $("#foo"), model: geekCollection });
geekCollection.fetch();
}
});
when browsing the url, the view loads correctly and at the server i see, that one entry is fetched from the database. but as soon as i check the model length in my view using
this.model.length
the collection is empty... any advice on this?
thanks
EDIT 1:
when changing the index router method to
var mapView = new App.GeeksMapView({ el: $("#map"), collection: geekCollection });
and e.g. check for the collection length in the views intialize method
...
initialize: function() {
this.render();
console.log(this.collection.length);
},
...
it retunes 0 as well... so nothing changed!
I believe you want to do collection.length or if accessing from the model - each model holds reference to collection in which it was created model.collection.length - if this is referencing to collection doing just this.length should be enough, if it's a model then this.collection.length will do it for you.
Models have no property length so should always be undefined unless you define it yourself.
I'm building my first backbone.js app, and I've run into a problem when trying to initialize my app and display both recipes and a shopping list, both of which are different (yet related) backbone objects.
My init function is
var MyApp= {
Models: {},
Views: {},
Routers: {},
Collections: {},
AppView: {},
Init: function() {
new MyApp.Views.ShoppingList;
new MyApp.Routers.Recipes;
Backbone.history.start();
}
};
Strangely, when I use
new MyApp.Routers.ShoppingList;
new MyApp.Routers.Recipes;
I don't get the shopping list View, I only get the recipes.
I also don't get any errors.
The shopping list router is fairly basic
MyApp.Routers.ShoppingList = Backbone.Router.extend({
routes: {
"": "index",
"shopping_list/:id": "show"
},
index: function(){
console.log('this');
new MyApp.Views.ShoppingList();
}
});
so from what I understand, the app should load the router, and display the view, but I'm not getting that or the console.log.
--------------as requested, here is my 'recipes router'---------------
MyApp.Routers.Recipes = Backbone.Router.extend({
routes: {
"": "index",
"recipes/:id": "show"
},
index: function(){
if(!MyApp.RecipeList){
MyApp.RecipeList = new MyApp.Collections.RecipeList;
MyApp.RecipeList.page = 1;
} else {
MyApp.RecipeList.page++;
}
MyApp.RecipeList.url='/recipes?page='+MyApp.RecipeList.page;
MyApp.RecipeList.fetch({
add: true,
success: function() {
new MyApp.Views.RecipeList({ collection: MyApp.RecipeList});
},
error: function() {
new Error({ message: "Error loading documents." });
}
});
},
show: function(id){
var recipe = MyApp.RecipeList.get(id);
new MyApp.Views.RecipeView({ model: recipe});
},
newRecipe: function(){
new App.Views.Edit({ model: new Recipe() });
},
edit: function(id){
var recipe = new Recipe({ id: id});
recipe.fetch({
success: function(model, resp){
new App.Views.Edit({ model: recipe});
},
error: function(){
new Error({message: "Hey!? Were'd it go? sorry I can't find your recipe"});
window.location.hash = '#';
}
});
}
});
----------------- some progress -----------------------------
I may be wrong, but in commenting out sections of the router, I find that the problem may be caused by my 'routes' as they both have index where the url is empty. Commenting out the 'routes' in one controller/router causes the other controller/router to display.
I've changed the routes so that they are more representative of their namespace
routes{
"recipes" : "recipes"
},
recipes: function()...
but I'm still not getting the right information to display. I'm now trying to figure out if I need an initialize function and what that would look like, or if I've even debugged this properly
--------------------- update, I was using backbone wrong ------------------------
It turns out I believe that I was mis-understanding Routers and was thinking of them more like controllers, so I was calling multiple routers on load, but the page was only loading the last one which pointed to an empty route as you can only request a single url route at a time.
Now I'm loading multiple Views on load and only one router.
After instantiating your view, you still need to render it and add it to the DOM.
index: function(){
console.log('this');
var view = new MyApp.Views.ShoppingList();
//you don't have to append to the whole body, but this is just an example
$('body').append(view.render().el);
}
Solution
in my route
Myapp.Routes = Backbone.Router.extend({
init: function(){
user = new User();
user.fetch({user,
success: function(response){
user.classlist = new classes(response.attributes.classes);
});
}
});
I've got a serialized json array being returned from my server, and I am trying to put the nested objects into my nested collections.
This answer, I thought was going to get me there, but I'm missing something.
How to build a Collection/Model from nested JSON with Backbone.js
The json which I am trying to populate my nested model with is
{first_name: "Pete",age: 27, classes: [{class_name: "math", class_code: 42},{class_name: "french", class_code: 18}]}
I create my user model
MyApp.Models.Users = = Backbone.Model.extend({
initialize: function(){
this.classlist = new MyApp.Collections.ClassList();
this.classlist.parent = this;
}
});
I had tried to follow the example on the other page, and use
this.classlist = new MyApp.Collections.ClassList(this.get('classes'));
this.classlist.parent = this;
but this.get('classes') returns undefined.
I've also tried getting the classes array through this.attributes.classes, but that is also undefined.
------------updated to include re-initialize --------------------
The function where I am initializing the user and classes is in the User routes and is called re-initialize. I use this function to fetch the user and their classes and store the object.
re_initialize: function(id){
user = new MyApp.Models.User();
MyApp.editingClasses.url = 'classes/'+id;
MyApp.editingClasses.fetch({
success: function(response){
MyApp.editingClasses.parse(response);
}
});
new MyApp.Views.ClassesInput();
},
As you can see, I'm calling the parse explicitly in the success function, but it isn't adding the classes to the collection.
I can't include the 'collection' because for some reason I can't access it in backbone.
the user model, after getting returned to backbone includes the classes array, which I am trying to put into the ClassList collection.
The user model object copied from the javascript terminal looks like this.
attributes: Object
created_at: "2012-01-05T16:05:19Z"
id: 63
classes: Array[3]
0: Object
created_at: "2012-01-18T20:53:34Z"
id: 295
teacher_id: 63
class_code: 42
updated_at: "2012-01-18T20:53:34Z"
class_name: math
__proto__: Object
1: Object
2: Object
length: 3
__proto__: Array[0]
You can use the parse function to pre-process the server response:
MyApp.Models.Users = Backbone.Model.extend({
parse: function(response) {
var classesJSON = response.classes;
var classesCollection = MyApp.Collections.ClassList(classesJSON);
response.classes = classesCollection;
return response;
}
});
var user = new MyApp.Models.Users();
user.fetch();
// You should now be able to get the classlist with:
user.get('classes');
That said, the approach suggested in the other question should also work. It could be that when your initialize function is called, the model hasn't yet been populated with the data?
For example, if you're doing:
var user = new MyApp.Models.Users();
It won't have any attributes yet to give to the classlist collection. Could that be your problem?
Okay! you can maybe fetch the classes this way :
Model :
window.person = Backbone.Model.extend({
defaults: { }
});
Collection :
window.ClassesCollection = Backbone.Collection.extend({
model: person,
url: "http://your/url/data.json",
parse: function(response){
return response.classes;
}
});
Router :
window.AppRouter = Backbone.Router.extend({
routes: {
"" : "init"
},
init: function(){
this.classesColl = new ClassesCollection();
this.classesColl.fetch();
this.classesView = new ClassesView({collection: this.classesColl});
}
});
View : (for rendering every classes)
window.ClassesView = Backbone.View.extend({
el: $('...'),
template: _.template($("...").html()),
initialize: function() {
this.collection.bind("reset", this.render, this);
},
render: function(collection) {
_.each( collection.models, function(obj){
...
//obj.get('class_name') or obj.get('class_code')
...
}, this );
...
return this;
}
});