backbone.js a url property must be defined - backbone.js

Question

I'm trying to use Backbone.localStorage as a backend to an app.
I wrote a Model called Era, and a corresponding EraView. Pressing enter in the EraView causes the model to be saved, and this is where I get the error:
Uncaught Error: A "url" property or function must be specified
urlError backbone.js:1509
_.extend.url backbone.js:515
_.result underscore-min.js:1060
Backbone.sync backbone.js:1410
Backbone.sync backbone.localStorage.js:188
_.extend.sync backbone.js:276
_.extend.save backbone.js:476
karass.EraView.Backbone.View.extend.close era.js:61
karass.EraView.Backbone.View.extend.updateOnEnter era.js:75
Here is the code to the EraView
var karass = karass || {};
// Era Item View
// the DOM element for an era item
karass.EraView = Backbone.View.extend({
tagName: 'li',
className: 'era',
template: _.template( $('#era-template').html() ),
// The DOM events specified to an item
events: {
'dblclick .edit-input': 'edit',
'keypress .edit-input': 'updateOnEnter',
//'blur .edit': 'close',
},
// The EraView listens for changes to its model, re-rendering. Since there's
// a one-to-one correspondence between an era and a EraView in this karass,
// we set a direct reference on the model for convenience.
initialize: function(){
_.bindAll(this);
this.model.on('change', this.render, this);
},
// Re-renders the era item to the current state of the model and
// updates the reference to the era's edit input within the view
render: function(){
this.$el.html( this.template(this.model.attributes));
this.$era_start = this.$('.era-start');
this.$era_end = this.$('.era-end');
this.$era_start.attr('disabled', true);
this.$era_end.attr('disabled', true);
return this;
},
// Switch this view into editing mode, displaying the input field
edit: function(){
this.$('.edit-input').removeAttr('disabled');
this.$el.addClass('editing');
this.$('.edit-input').addClass('editing');
},
// Close the editing mode, saving changes to the era
close: function(){
this.$('.edit-input').attr('disabled', true);
var start = this.$era_start.val().trim();
var end = this.$era_end.val().trim();
if(start && end){
this.model.save({from: start, until: end});
}
this.$el.removeClass('editing');
this.$('.edit-input').removeClass('editing');
this.trigger('close');
},
updateOnEnter: function(e){
if(e.which !== ENTER_KEY && (!this.$era_start.val().trim() || !this.$era_end.val().trim())){
return;
}
this.close();
}
});
And this is the code for the era model:
var karass = karass || {};
karass.Era = Backbone.Model.extend({
defaults: {
from: '',
until: ''
},
});
I thought I didn't need a url while using localStorage.
Edit: I forgot to mention that while this behavior occurs in the Era/EraView itself, it also occurs in the Name model, which extends Era. Name in turn belongs in a Names collection. I don't know if this makes a difference, but I figured I add it.
Edit 2: The Names collection looks like this:
karass.Names = History.extend({
model: karass.Name,
localStorage: new Backbone.LocalStorage('karass-names'),
});
Edit 3: I posted all the code on jsfiddle: http://jsfiddle.net/herrturtur/CRv6h/

Answer 1

You don't need an url while using localStorage. But you need to set the localStorage property on your model or on your collection (if you set the localStorage on a collection the models inside the collection will "inherit" this setting):
karass.Era = Backbone.Model.extend({
localStorage: new Backbone.LocalStorage("EraCollection"),
// the EraCollection should be an unique name within your app.
defaults: {
from: '',
until: ''
},
});
If you don't setup the localStorage property the plugin falls back to the default ajax sync so you get the uri missing exception.