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Events Wont work on Backbone.js

I created a view and has the ff codes:
var app = app || {};
app.singleFlowerView = Backbone.View.extend({
tagName: 'article',
className: 'flowerListItem',
// tells where to apply the views
template: _.template( $("#flowerElement").html() ),
// render
render: function(){
var flowerTemplate = this.template(this.model.toJSON());
// el contains all the prop above and pass to backbone
this.$el.html(flowerTemplate);
return this;
},
events: {
'mouseover': 'addBgColor',
'mouseout': 'removeBgColor'
},
addBgColor: function(){
this.$el.addBgColor('bgColorImage');
},
removeBgColor: function(){
this.$el.removeBgColor('bgColorImage');
}
});
When I run this to my HTML file I got the error addBgColor and removeBgColor is not a function. I have the CSS for this and all the models and views were set up.
Am I missing something here? Any idea why events doesn't work?

this.$el.addBgColor is the problem.
The events are triggering but you're calling addBgColor on the $el jQuery object, which is not a jQuery function, like the error message is telling you.
Check what's the difference between $el and el.

Tony, your events are cool and they are running they're just not doing anything.
this.addBgColor() will call your function in a view.
this.$el is referring to the html and there's no property called addBgColor assigned to $el.
You need to do something like change the class on your tag with the functions like so...
addBgColor: function(){
this.$el.className = 'bgColorImage'
},
.bgColorImage {
background-image: url('bgColorImage.jpg');
}

this.$el.off is not a function

Previously this will work but I've update the underscore and backbone to the latest version, then I got error of
Uncaught TypeError: this.$el.off is not a function
http://jsfiddle.net/mmm770v8/
SearchView = Backbone.View.extend({
initialize: function(){
this.render();
},
render: function(){
var template = _.template( $("#search_template").html(), {} );
this.el.html( template );
},
events: {
"click input[type=button]": "doSearch"
},
doSearch: function(){
// Button clicked
console.log(this.el.find('#search_input').val());
}
});

You have several problems:
Your fiddle was using jQuery 1.5.2 which is ancient and used bind/unbind instead of on/off. Backbone expects a more recent version of jQuery which has on and off functions.
You're using this.el where you mean this.$el. this.el is just a plain old DOM node, this.$el is the cached $(this.el).
The var html = _.template(tmpl, data) form of _.template went away in Underscore 1.7.0. You now need a two step process:
var t = _.template(tmpl);
var h = t(data);
so your render should look more like this:
render: function() {
var template = _.template($("#search_template").html());
this.$el.html(template({}));
}
Updated fiddle: http://jsfiddle.net/ambiguous/L5z4agh4/

How does this click handler get assigned to a DOM element?

Now that I understand Backbone a little better (I Hope) I've been going through this App with a fine tooth comb to understand how it works:
https://github.com/ccoenraets/nodecellar/tree/master/public
The latest thing that's stumped me is the EL tag in windetails.js (here: https://github.com/ccoenraets/nodecellar/blob/master/public/js/views/winedetails.js)
I'll paste the relevant code below, but my question is how does this view's EL property get assigned? As you'll notice in the view definition no EL tag is defined, nor is there an idTag or className property assigned. However I verified in firebug that this view is indeed listening on a DIV tag in the middle of the DOM (just underneath the content DIV actually). So how did it get attached there? If not for that the Click handler would not work properly but it does. All of the previous views which look like there were created in the same way have unattached EL properties.
window.WineView = Backbone.View.extend({
initialize: function () {
this.render();
},
render: function () {
$(this.el).html(this.template(this.model.toJSON()));
return this;
},
events: {
"change" : "change",
"click .save" : "beforeSave",
"click .delete" : "deleteWine",
"drop #picture" : "dropHandler"
},
change: function (event) {
// Remove any existing alert message
utils.hideAlert();
// Apply the change to the model
var target = event.target;
var change = {};
change[target.name] = target.value;
this.model.set(change);
// Run validation rule (if any) on changed item
var check = this.model.validateItem(target.id);
if (check.isValid === false) {
utils.addValidationError(target.id, check.message);
} else {
utils.removeValidationError(target.id);
}
},
beforeSave: function () {
var self = this;
var check = this.model.validateAll();
if (check.isValid === false) {
utils.displayValidationErrors(check.messages);
return false;
}
this.saveWine();
return false;
},
saveWine: function () {
var self = this;
console.log('before save');
this.model.save(null, {
success: function (model) {
self.render();
app.navigate('wines/' + model.id, false);
utils.showAlert('Success!', 'Wine saved successfully', 'alert-success');
},
error: function () {
utils.showAlert('Error', 'An error occurred while trying to delete this item', 'alert-error');
}
});
},
deleteWine: function () {
this.model.destroy({
success: function () {
alert('Wine deleted successfully');
window.history.back();
}
});
return false;
},
dropHandler: function (event) {
event.stopPropagation();
event.preventDefault();
var e = event.originalEvent;
e.dataTransfer.dropEffect = 'copy';
this.pictureFile = e.dataTransfer.files[0];
// Read the image file from the local file system and display it in the img tag
var reader = new FileReader();
reader.onloadend = function () {
$('#picture').attr('src', reader.result);
};
reader.readAsDataURL(this.pictureFile);
}
});
EDIT
There's been a lot of talk about this pattern:
$(x).append(v.render().el)
Someone correct me if I'm wrong but as I understand it this is a Jquery call to update the DOM at the "x" tag with the contents of the "el" property from the v object (after render is called). This technique should render content into the DOM EVEN IF the "el" property has not previously been set and is an "unattached div" provided it has had valid content previously written to it from the render method.
However after the content has been written to the DOM the "el" property still remains an unattached div until it is directly assigned to the DOM.
I verified through Firebug that this Backbone app has two views which are rendered this exact way and both have unattached div el properties. Those are the wineList view and the homeView. However, the 3rd view is the WineDetail view and it does not seem to have an unattached EL property. It's EL property seems to be attached and furthermore is facilitating a click event. My question is how did this EL property get attached and assigned to the DOM?

The answer can be found by looking at the internals of Backbone.View.
Looking at the constructor:
var View = Backbone.View = function(options) {
this.cid = _.uniqueId('view');
this._configure(options || {});
//this function is responsible for the creation of the `this.el` property.
this._ensureElement();
this.initialize.apply(this, arguments);
this.delegateEvents();
};
Ensure that the View has a DOM element to render into. If this.el is a
string, pass it through $(), take the first matching element, and
re-assign it to el. Otherwise, create an element from the id,
className and tagName properties. http://backbonejs.org/docs/backbone.html#section-133
Now that we know where this.el comes from, have a look at the events docs to see how it's handled.
The view is instantiated in main.js
$('#content').html(new WineView({model: wine}).el);
EDIT:
None of which explains how the View Object's EL property is set and
and how the click trigger works.
I will try to explain it better:
this.el is created by a call to this._ensureElement in the Backbone.View constructor. We can also see that this.render is called from the initialize function which runs at instanciation time. We can see that in this.render, we set the content of this.el to the result of applying this.template to the model.
Now, during the initialization process of a Backbone.View, right after this.initialize is called, the events config is processed by making a call to this.delegateEvents. This is where event listeners will get attached using the given selectors. Note that most events will get attached directly to this.el and make use of event delegation, instead of attaching the events directly on the children elements.
At this point, we are left with a this.el that contains all the necessary markup and has all the event listeners setup. However, this.el is still not part of the DOM yet.
But from the code, we can see that this.el will be attached to the DOM as a children of the #content element after the instanciation of the view:
$('#content').html(new WineView({model: wine}).el);

The last three lines in this piece of code:
events: {
"change" : "change",
"click .save" : "beforeSave",
"click .delete" : "deleteWine",
"drop #picture" : "dropHandler"
},
look like this pattern (looking at the 2nd line in the events structure):
"click" = event to register a handler for
".save" = selector to use for selecting objects for the event handler
beforeSave = method to call when the event fires

Backbone View not selecting element

This is my first time create a view with Backbone, but I'm not able to render changes to an existing element in the document.
var ParamsView = Backbone.View.extend({
el: $('#node-parameters'),
initialize: function() {
console.log('WOW');
},
render: function() {
console.log('doing it');
console.log(this.$el.length);
console.log($('#node-parameters').length);
this.$el.append('<span>hello world!</span>');
return this;
}
});
var v = new ParamsView();
v->render();
The words hello world! do not appear in the target div.
The console outputs the following when the view is rendered.
WOW
doing it
0
1
So I know that my jQuery selector $('#node-parameters') is finding 1 DOM element, but the view is not use it.
Any ideas what I'm doing wrong?
EDIT: In the JS debugger I can see that this.el is undefined for the view.

Your code is probably equivalent to this :
var ParamsView = Backbone.View.extend({
el: $('#node-parameters'),
initialize: function() {
console.log('WOW');
},
render: function() {
console.log('doing it');
console.log(this.$el.length);
console.log($('#node-parameters').length);
this.$el.append('<span>hello world!</span>');
return this;
}
});
$(document).ready(function() {
var v = new ParamsView();
v.render();
});
http://jsfiddle.net/nikoshr/mNprr/
Notice that you class is declared before the DOM ready event.
You set the el at extend time with $('#node-parameters'). $ is a function that is immediately executed but, and that's why you get an undefined element, #node-parameters does not exist at that point.
By injecting the element with new ParamsView({el: '#node-parameters'}), you set a valid el after the DOM ready event. You could also set it via
var ParamsView = Backbone.View.extend({
el: '#node-parameters'
});
el is then evaluated when you instantiate your class, after the DOM ready event. http://jsfiddle.net/nikoshr/mNprr/1/

backbone and $el element

I'm trying to develop my first backbone application. All seems ok, but when i render the view and append some html to the $el, nothing is rendered in the page.
Rest service calls done ok, the Backbone.Router.extend is declared inside $(document).ready(function () {}); to ensure that the DOM is created.
Debugging my javascript, the el element get to contain the correct value in the innerHTML property, but when the whole page is rendered, this value doesn't appear in the page.
¿What am i doing wrong?
My View code:
window.ProductsListView = Backbone.View.extend({
id: 'tblProducts',
tagName: 'div',
initialize: function (options) {
this.model.on('reset', this.render, this);
},
render: function () {
// save a reference to the view object
var self = this;
// instantiate and render children
this.model.each(function (item) {
var itemView = new ProductListItemView({ model: item });
var elValue = itemView.render().el;
self.$el.append(elValue); // Here: the $el innerHTML is ok, but in the page it disappear. The id of element is div#tblProducts, so the element seems correct
});
return this;
}
});
window.ProductListItemView = Backbone.View.extend({
tagName: 'div',
template: _.template(
'<%= title %>'
),
initialize: function (options) {
this.model.on('change', this.render, this);
this.model.on('reset', this.render, this);
this.model.on('destroy', this.close, this);
},
render: function () {
$(this.el).html(this.template(this.model.toJSON()));
// $(this.el).html('aaaaaa'); // This neither works: it's not a template problem
return this;
},
close: function () {
$(this.el).unbind();
$(this.el).remove();
}
});
Here i load products (inside Backbone.Router.extend). This is executed correctly:
this.productsList = new ProductsCollection();
this.productsListView = new ProductsListView({ model: this.productsList });
this.productsList.fetch();
And this is the html element i want to render:
<div id="tblProducts">
</div>
Thanks in advance,

From the code you have posted, you are not actually inserting your ProductsListView in to the DOM or attaching it to an existing DOM element.
The way I like to look at it is you have two types of Views:
Those that are dynamically generated based on data returned from the server
Those that already exist on the page
Usually in the case of lists, the list already exists on the page and it's items are dynamically added. I have taken your code and restructured it slightly in this jsfiddle. You will see that the ProductListView is binding to an existing ul, and ProductItemView's are dynamically appended when they are added to the Collection.
Updated jsfiddle to demonstrate Collection.reset

The el property exists within the view if it is rendered or not. You can't say it is ok there because Backbone will create an element if no element is passed (empty div).
If you want to render the view you should determine what is the container of the element? Do you have an html you want to attach the view to?
Try passing a container element by calling the view with an el like
this.productsListView = new ProductsListView({ model: this.productsList, el : $("#container") });
Of course you can create the view and attach it to the DOM later:
el: $("#someElementID") //grab an existing element
el.append(view.render().el);
Your view wont exist in the dom until you attach it somewhere.