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Passed parameter to initialize() view is undefined in Backbone.js

I'm working on a Backbone.js app which utilizes a 'master view' which all views and subviews extend from.
Master view
define(['backbone'], function (Backbone) {
return Backbone.View.extend({
events: {
},
showSuccess: function (msg) {
alert(msg);
}
});
});
I then have a Main View which generates the page, this can call on sub views for smaller parts:
define(['backbone','masterView', 'mySubView'], function (Backbone, mView, mySubView) {
var mainView = mView.extend({
events: function () {
return _.extend({}, coreView.prototype.events, {
});
},
render: function () {
var sub = new mySubView({'foo': 'bar'});
}
});
return new mainView();
});
Finally, my subview, which when it's initialised, it says that options is undefined.
define(['backbone','masterView', 'mySubView'], function (Backbone, mView, mySubView) {
var subView = mView.extend({
events: function () {
return _.extend({}, coreView.prototype.events, {
});
},
initialize: function (options) {
console.log(options);
}
});
return new subView();
});
In this setup, why is options undefined when I passed them in my MainView? If the subview doesn't extend masterView, but Backbone.view instead, it works fine.

Your last line in the subview file:
return new subView();
You're returning a new instance instead of returning the constructor in the subview module. It should be:
return subView;
Note that as a convention, JavaScript code should use PascalCase for types (constructor, classes, etc.), and instances (variables, properties, etc.) should use camelCase.
Also, I'm sharing tricks on how to design a good base class with Backbone. You could shift the responsibility of merging the events to the base class instead of each child class.

Not fetching correct url issue

I have a backboneJS app that has a router that looks
var StoreRouter = Backbone.Router.extend({
routes: {
'stores/add/' : 'add',
'stores/edit/:id': 'edit'
},
add: function(){
var addStoresView = new AddStoresView({
el: ".wrapper"
});
},
edit: function(id){
var editStoresView = new EditStoresView({
el: ".wrapper",
model: new Store({ id: id })
});
}
});
var storeRouter = new StoreRouter();
Backbone.history.start({ pushState: true, hashChange: false });
and a model that looks like:
var Store = Backbone.Model.extend({
urlRoot: "/stores/"
});
and then my view looks like:
var EditStoresView = Backbone.View.extend({
...
render: function() {
this.model.fetch({
success : function(model, response, options) {
this.$el.append ( JST['tmpl/' + "edit"] (model.toJSON()) );
}
});
}
I thought that urlRoot when fetched would call /stores/ID_HERE, but right now it doesn't call that, it just calls /stores/, but I'm not sure why and how to fix this?
In devTools, here is the url it's going for:
GET http://localhost/stores/

This might not be the answer since it depends on your real production code.
Normally the code you entered is supposed to work, and I even saw a comment saying that it works in a jsfiddle. A couple of reasons might affect the outcome:
In your code you changed the Backbone.Model.url() function. By default the url function is
url: function() {
var base =
_.result(this, 'urlRoot') ||
_.result(this.collection, 'url') ||
urlError();
if (this.isNew()) return base;
return base.replace(/([^\/])$/, '$1/') + encodeURIComponent(this.id);
},
This is the function to be used by Backbone to generate the URL for model.fetch();.
You added a custom idAttribute when you declared your Store Model to be like the one in your DB. For example your database has a different id than id itself, but in your code you still use new Model({ id: id }); when you really should use new Model({ customId: id });. What happens behind the scenes is that you see in the url() function it checks if the model isNew(). This function actually checks if the id is set, but if it is custom it checks for that:
isNew: function() {
return !this.has(this.idAttribute);
},
You messed up with Backbone.sync ... lots of things can be done with this I will not even start unless I want to make a paper on it. Maybe you followed a tutorial without knowing that it might affect some other code.
You called model.fetch() "a la" $.ajax style:
model.fetch({
data: objectHere,
url: yourUrlHere,
success: function () {},
error: function () {}
});
This overrides the awesomeness of the Backbone automation. (I think sync takes over from here, don't quote me on that).
Reference: Backbone annotated sourcecode

Change page view with Backbone

I've implemented "change page" in my one page application with Backbone.js. However, I'm not sure if my Router should contain so much business logic. Should I consider go with Marionette.js to implement such functionality and make my Router thin? Should I worry about destroying Backbone models and views attached to "previous" active page/view when I change it (in order to avoid memory leaks) or it's enough to empty html attached to those models/views.
Here is my Router:
App.Router = Backbone.Router.extend({
routes: {
'users(/:user_id)' : 'users',
'dashboard' : 'dashboard'
},
dashboard: function() {
App.ActiveView.destroy_view();
App.ActiveViewModel.destroy();
App.ActiveViewModel = new App.Models.Dashboard;
App.ActiveViewModel.fetch().then(function(){
App.ActiveView = new App.Views.Dash({model: App.ActiveViewModel });
App.ActiveView.render();
});
},
users: function(user_id) {
App.ActiveView.destroy_view();
App.ActiveViewModel.destroy();
App.ActiveViewModel = new App.Models.User;
App.ActiveViewModel.fetch().then(function() {
App.ActiveView = new App.Views.UsersView({model: App.ActiveViewModel});
App.ActiveView.render();
});
}
});

Another approach:
Create an AbstractView
Having an AbstractView declared and then extending your other application specific View's from AbstractView has many advantages. You always have a View where you can put all the common functionalities.
App.AbstractView = Backbone.View.extend({
render : function() {
App.ActiveView && App.ActiveView.destroy_view();
// Instead of destroying model this way you can destroy
// it in the way mentioned in below destroy_view method.
// Set current view as ActiveView
App.ActiveView = this;
this.renderView && this.renderView.apply(this, arguments);
},
// You can declare destroy_view() here
// so that you don't have to add it in every view.
destroy_view : function() {
// do destroying stuff here
this.model.destroy();
}
});
Your App.Views.UsersView should extend from AbstractView and have renderView in place of render because AbstractView's render will make a call to renderView. From the Router you can call render the same way App.ActiveView.render();
App.Views.UsersView = AbstractView.extend({
renderView : function() {
}
// rest of the view stuff
});
App.Views.Dash = AbstractView.extend({
renderView : function() {
}
// rest of the view stuff
});
Router code would then change to :
dashboard: function() {
App.ActiveViewModel = new App.Models.Dashboard;
App.ActiveViewModel.fetch().then(function(){
new App.Views.Dash({model: App.ActiveViewModel }).render();
});
}

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
});

how to extend a backbone view

I am new in SPA's with backbone and I am trying to develop a small app by using backbone and requireJs.
The problem I faced is that I can't extend a view by passing a collection.
Well, this is the view with name MenuView.js
define([
'Backbone'
], function (Backbone) {
var MenuView = Backbone.View.extend({
tagName: 'ul',
render: function () {
_(this.collection).each(function (item) {
this.$el.append(new MenuListView({ model: item }).render().el);
}, this);
return this;
}
});
return new MenuView;
});
and this is the router.js in which the error is appeared
define([
'Underscore',
'Backbone',
'views/menu/menuView',
'views/createNew/createNew',
'collections/menu/menuCollection',
], function (_, Backbone, MenuView, CreateNewView,Menucollection) {
var AppRouter = Backbone.Router.extend({
routes: {
'index': 'index',
'action/:Create': 'Create'
},
index: function () {
CreateNewView.clear();
//----------- HERE IS THE PROBLEM ------------
$('#menu').html(MenuView({ collection: Menucollection.models }).render().el);
},
Create: function () {
CreateNewView.render();
}
});
var initialize = function () {
var appRouter = new AppRouter();
Backbone.history.start();
appRouter.navigate('index', { trigger: true });
};
return {
initialize: initialize
};
});
The error message is "object is not a function". I agreed with this since the MenuView is not a function. I tried to extend the MenuView (MenuView.extend({collection:Menucollection.models})) and the error message was "objet[object,object] has no method extend".
I suppose that the way I am trying to do this, is far away from the correct one.
Could anyone suggest how to do this?
Thanks

#Matti John's solution will work, but it's more of a workaround than a best practice IMHO.
As it is, you initializing your view just by requiring it, which:
Limits you to never accept arguments
Hits performance
Makes it really hard to unit-test if you relay on assigning properties ater constructing an instance.
A module should be returning a 'class' view and not an instance on that view.
In MenuView.js I would replace return new MenuView with return MenuView; and intitalzie it when required in router.js.

Your MenuView.js returns an initialized MenuView, so you could just do:
MenuView.collection = Menucollection
Note I haven't selected the models - I think it's better if you don't use the models as a replacement for your view's collection, since it would be confusing to read the code and not have a Backbone collection as the view's collection. You would also lose the method's contained within the collection (e.g. fetch/update).
If you do this, then you would need to update your loop (each is available as a method for the collection):
this.collection.each(function (item) {
this.$el.append(new MenuListView({ model: item }).render().el);
}, this);