Develop Reference

Refresh page to see content

I've created a Rails app using Backbone, but I've run into a small but annoying problem. When a user goes to his profile and then back to the frontpage the frontpage is empty and I have to refresh it in order to show the content of the backbone view.
In my Movieseat.Routers.Movieseats I have:
routes:
'': 'index'
initialize: ->
#movieSeats = new Movieseat.Collections.Movieseats()
#movieSeats.fetch()
#searchResults = new Movieseat.Collections.Moviesearch()
index: ->
view = new Movieseat.Views.MovieseatsIndex(collection: #movieSeats)
$('#container').html(view.render().el)
Any idea on why users have to refresh to see the frontpage?

I don't know CoffeeScript but the fetch() method takes a success callback where you can ensure the collection has loaded. In your index you're creating a new view passing the #movieSeats collection but the collection may have not been loaded by that time. Try the following:
{
routes: {
'': 'index'
},
initialize: function() {
this.movieSeats = new Movieseat.Collections.Movieseats();
},
index: function() {
var self = this, view;
this.movieSeats.fetch({
success: function(collection) {
view = new Movieseat.Views.MovieseatsIndex({ collection: collection })
$('#container').html(view.render().el)
}
});
}
}
However, you might want to "bootstrap" your collection like is shown on the Backbone docs: http://documentcloud.github.io/backbone/#FAQ-bootstrap

pass parameters to backbone fetch url to deal with a non-standard api

I am trying to manipulate backbone's fetch method to to deal with a bit of a non-standard api. The way the api works is as follows:
api/products/[page]?param1=val&param2=val
ex:
api/products/2?budget=low&categories=all
would be equivalent to getting the second page of results for which the budget is low and all categories are included.
I can pass the parameters after the query string just fine through the format:
self.productsItemsCollection.fetch({ success : onDataHandler, dataType: "json", data: { budget: 'low', categories: 'all' } });
but I'm not sure what to do about the pagination, since it comes before the ? question mark.
Here is how the collection is set up:
define([
'underscore',
'backbone',
'models/products/ProductsItemsModel'
], function(_, Backbone, ProductsItemsModel){
var ProductsItemsCollection = Backbone.Collection.extend({
model: ProductsItemsModel,
initialize : function(models, options) {}, //MH - need to pass filters to this function
url : function() {
return '/api/products/'; //MH - need to pass page number to be appended to this url
},
parse : function(data) {
debugger;
return data.items;
}
});
return ProductsItemsCollection;
});
How do I include the pagination in backbone's fetch command given this api URL structure?

You're on the right track in that Backbone can use the return value of a function as its 'url' value. What I personally would do, is set a page property on the collection (referenced through something like this.page), and include that in the output of the url function.
initialize: function() {
this.page = 1; // Or whatever the default should be
},
url: function() {
return '/api/products/ + this.page;
}
The problem then becomes updating the page property, which can be as simple as 'ProductsItemsCollection.page = 2;'. Personally, I would also add a second fetch method to wrap the page update and fetch into a single method call.
fetch2: function(page, options) {
if (page) {
this.page = page;
}
return this.fetch(options);
}

Just few notes to your code. I think you don't need to define page number into your Collection. According to MVC pattern it's more suitable for Controller. Collection just should get parameter and return some data according to it. Meanwhile Backbone doesn't provide classic MVC Controller, but you can use for this purpose Backbone.View. So structure of your application could looks something like this:
// Collection
define([
'backbone',
'models/products/ProductsItemsModel'
], function(Backbone, ProductsItemsModel){
return Backbone.Collection.extend({
// I don't know what exactly your Model does, but if you don't override Backbone.Model with your own methods you don't really need to define it into your collection.
model: ProductsItemsModel,
initialize : function(models, options) {}, //MH - need to pass filters to this function
url : function(page) {
return '/api/products/' + page;
},
parse : function(data) {
return data.items;
}
});
});
And then in your View you can fetch needed page and render it:
define([
'jquery',
'backbone',
'ProductsItemsCollection'
], function($, Backbone, ProductsItemsCollection){
return Backbone.View.extend({
events: {
// Your logic to get page number from your pagination.
'click .pagination': 'getPageNumber'
}
collection: new ProductsItemsCollection(),
initialize : function() {
this.listenTo(this.collection, 'reset', this.render);
// initial loading collection
this.load(1); // load page #1
},
render: function () {
// your render code
}
// Example function to show how you could get page number.
getPageNumber: function(e) {
var pageNumber = $(e.currentTarget).data('pageNumber');
load(pageNumber);
},
load: function(page) {
url: this.collection.url(page),
data: {
budget: 'low',
categories: 'all'
}
}
});
});
Something like that. So in this View you just make initialization of your Collection and make initial loading. Then all you should make is passing page number to your load function.

I read these answers, i guess they make sense but this is what i went with. just really simple:
app.WorkOrder = Backbone.Collection.extend({
model: app.WorkOrderDetail,
urlRoot: '/m2/api/w/',
getWorkOrder: function(workorder_id, options) {
this.url = this.urlRoot + workorder_id;
return this.fetch(options);
}
});
Then in the view i do this:
app.AppView = Backbone.View.extend({
el: '#workorderapp',
initialize: function () {
app.workOrder.getWorkOrder(workorder_id, {
success:function(data) {
//...do something with data
}
});
},
});

Backbone targetModel = undefined

I am running into this issue with backbone where the model seems to be undefined to backbone, though all scripts are loaded.
(I am using require to load backbone and other javascript files).
So whenever I do a collection.fetch I get this error in firebug:
TypeError: targetModel is undefined
When I run the script it holds at this point:
if (attrs instanceof Model) {
id = model = attrs;
} else {
id = attrs[targetModel.prototype.idAttribute];
}
when I hover with my mouse over targetModel it says: undefined
It somehow doesn't seem to work now and the only thing I did was changing my html template, which only get loaded after the collection.fetch.
Can you please help me out here?
Here is my model:
var OF = OF || {};
OF.UsersMdl = Backbone.Model.extend({
default: {
username: '',
mailinglist: '',
email: ''
},
initialize: function() {
//
},
result: {
success: false,
message: ''
},
validate: function(att) {
}
});
Here is the collection:
var OF = OF || {};
OF.UsersCollection = Backbone.Collection.extend({
initialize: function() {
//
},
parse: function(data){
return data["all-users"];
},
model: OF.UsersMdl,
url: 'php/api/users'
});
And last but not least the router with the require part:
goToUsers: function() {
require(['./models/users', './views/users_view', './collections/user_collection'], function(UsersMdl, UsersView, UsersCollection) {
OF.usersMdl = new OF.UsersMdl;
OF.usersCollection = new OF.UsersCollection;
OF.usersView = new OF.UsersView;
//when the collection is fetched
$.when(OF.usersCollection.fetch({
data: {
"admin": OF.login.attributes.admin,
"session": OF.login.attributes.session
},
success: function(){
//console.log(OF.usersCollection.length);
}
//then render the view
})).then(function(){
OF.usersView.render();
}, 300);
});
},
Here is the JSON which will be retreived by the fetch:
{
"all-users":
[
{
"username":"tester",
"mailinglist":"1",
"email":"tester#tester.test"
},
{
"username":"tester2",
"mailinglist":"1",
"email":"tester2#tester.test"
},
{
"username":"tester3",
"mailinglist":"0",
"email":"tester3#tester.test"
}
]
}
Thanks in advance

I had this same error and banged my head against it for quite a while because backbone is new to me and this was compounding a fetch issue. Anyhow, I eventually figured out that order matters. Doh! (Less obvious when using CoffeeScript and "class" statements I thinks.) With one of my models I was setting the Collection before the Model (thanks to bad example code from the Backbone.js on Rails book). I reversed that and this error went away to reveal my true fetch issue.
Similarly, your model: property may be invalid for this reason or another reason, leaving it undefined when attempting to reference later.
Side note: I had a similar error in Backbone 1.0.0. When I upgraded to Backbone 1.1.0 I then got this exact error at the same point in backbone code.

Backbone.js and local storage . A "url" property or function must be specified

I'm improving my knowledge about Backbone.js and have this code sample taken from a tutorial. (http://bardevblog.wordpress.com/2012/01/16/understanding-backbone-js-simple-example/)
This example will not access the server for now, so to simulate the retrieval of data from the server I have a file name movies.json.
What I am trying to do:
Add json data in local storage (using localStorage adapter)
For this I am using Backbone.ajaxSync, Which Is Given to the alias Backbone.sync by the localStorage adapter: I created the method refreshFromServer () to do this
The reason for doing this is that I'm trying to implement a way to get data only one time (and only refresh when i need to)
My issues:
  I'm having an error "Uncaught Error: 'url' property or function must be specified" when I call refreshFromServer ().
I do not understand why because I set the url collection. (url : "scripts/data/movies.json" )
Sample code
var Theater = {
Models : {},
Collections : {},
Views : {},
Templates : {}
}
Theater.Models.Movie = Backbone.Model.extend({})
Theater.Collections.Movies = Backbone.Collection.extend({
model : Theater.Models.Movie,
localStorage : new Backbone.LocalStorage("MovieStore"), // Unique name within your app.
url : "scripts/data/movies.json",
refreshFromServer : function() {
return Backbone.ajaxSync.apply(this, arguments);
},
initialize : function() {
console.log("Movies initialize")
}
});
Theater.Templates.movies = _.template($("#tmplt-Movies").html())
Theater.Views.Movies = Backbone.View.extend({
el : $("#mainContainer"),
template : Theater.Templates.movies,
initialize : function() {
this.collection.bind("reset", this.render, this);
},
render : function() {
console.log("render")
console.log(this.collection.length);
}
})
Theater.Router = Backbone.Router.extend({
routes : {
"" : "defaultRoute"
},
defaultRoute : function() {
console.log("defaultRoute");
Theater.movies = new Theater.Collections.Movies()
new Theater.Views.Movies({
collection : Theater.movies
});
Theater.movies.refreshFromServer();
//Theater.movies.fetch();
console.log(Theater.movies.length)
}
})
var appRouter = new Theater.Router();
Backbone.history.start();
Notes:
If a comment localStorage property in the collection
Theater.Models.Movie = Backbone.Model.extend({})
Theater.Collections.Movies = Backbone.Collection.extend({
model : Theater.Models.Movie,
//localStorage : new Backbone.LocalStorage("MovieStore")
...
});
and then in router call normal fetch method
Theater.Router = Backbone.Router.extend({
routes : {
"" : "defaultRoute"
},
defaultRoute : function() {
Theater.movies = new Theater.Collections.Movies()
new Theater.Views.Movies({
collection : Theater.movies
});
//Theater.movies.refreshFromServer();
Theater.movies.fetch();
}
})
I can see the json list correctly in my view
If I use the localStorage property in the collection and then call the standard fetch () method, I see only an empty list (I think it is normal as it is read from the local storage and is empty)
The error only occurs when using the method refreshFromServer () witch use Backbone.ajaxSync (alias for backbone.sync)

Err... my bad. The refreshFromServer implementation is from my answer to your earlier question., and it's completely, uselessly wrong.
Backbone.sync expects arguments (method, model, options), but as it stands, it doesn't get what it needs from refreshFromServer because the refresh method simply sends forward whatever arguments it gets. Sorry for the mistake.
The correct, working implementation would be:
refreshFromServer : function(options) {
return Backbone.ajaxSync('read', this, options);
}
It can be used either via success / error callbacks passed to the options hash:
this.collection.refreshFromServer({ success: function() { /* refreshed... */ });
Or via the jqXHR Promise API:
this.collection.refreshFromServer().done(function() { /* refreshed... */ })
Or not signing up for callbacks and waiting for the collection reset event like in your example:
this.collection.bind("reset", this.render, this);
this.collection.refreshFromServer();
This should work. Please let me know if it doesn't. I fixed my answer in the previous question too, in case someone stumbles onto it.
Edit: To save the data to local storage after refreshing you need to manually save each of the models:
var collection = this.collection;
collection.refreshFromServer({success: function(freshData) {
collection.reset(freshData);
collection.each(function(model) {
model.save();
});
}});

How do I bind an event to a model that isn't loaded yet?

So I've got a pretty simple backbone app with a model, a collection, and a couple of views. I'm fetching the actual data from the server by doing a collection.fetch() at page load.
My problem is that one of my views is a "detail" view, and I want to bind it to a particular model - but I don't have the model yet when the page loads. My code looks a lot like this:
window.App = {
Models: {},
Collections: {},
Views: {},
Routers: {}
}
App.Models.Person = Backbone.Model.extend({
urlRoot: '/api/people'
});
App.Collections.People = Backbone.Collection.extend({
model: App.Models.Person,
url: '/api/people'
});
people = new App.Collections.People()
App.Views.List = Backbone.View.extend({
initialize: function() {
this.collection.bind('reset', this.render());
},
render: function() {
$(this.el).html("We've got " + this.collection.length + " models." )
}
});
listView = new App.Views.List({collection: people})
App.Views.Detail = Backbone.View.extend({
initialize: function() {
this.model.bind('change', this.render());
},
render: function() {
$(this.el).html("Model goes here!")
}
});
App.Routers.Main = Backbone.Router.extend({
routes: {
'/people': 'list',
'/people/:id': 'detail'
},
list: function() {
listView.render();
},
detail: function(id) {
detailView = new App.Views.Detail({model: people.get(id)})
detailView.render()
}
})
main = new App.Routers.Main();
Backbone.history.start();
people.fetch();
But if I start with the detail route active, the people collection is empty, so people.get(id) doesn't return anything, so my new view has this.model undefined, and won't let me bind any events relating to it. The error is:
Uncaught TypeError: Cannot call method 'bind' of undefined
If I start with the list route active, then by the time I click on an item to bring up the detail view people is populated, so everything works.
What's the right way to bind model-related events for a "detail" view when you're fetching the data after page load?

You have a part of the answer here: Backbone.js Collections not applying Models (using Code Igniter)
Indeed, you need to wait that people.fetch finishes its ajax request before to call Backbone.history.start(); and trigger the actual route.
Your code should look like:
// [...]
main = new App.Routers.Main();
peoples.fetch({
success: function (collection, response) {
// The collection is filled, trigger the route
Backbone.history.start();
}
});
You can add a loader on the page and hide it when the collection is loaded.