Backbone view event atacched to all views - backbone.js

I'm doing my first application in backbone and i get a strange thing happening trying to attach an event.
I got this code so far:
//View for #girl, EDIT action
GirlEditView = Backbone.View.extend({
initialize: function(el, attr) {
this.variables = attr;
console.log(attr);
this.render();
},
render: function() {
var template = _.template( $("#girl_edit").html(), this.variables );
$(this.el).html( template );
$("#edit_girl").modal('show');
}
});
//View for #girl
GirlView = Backbone.View.extend({
initialize: function(el, attr) {
this.variables = attr;
this.render();
},
render: function() {
var template = _.template( $("#girl_template").html(), this.variables );
$(this.el).html( $(this.el).html() + template );
},
events: {
"click p.modify": "modify"
},
modify: function() {
//calls to modify view
new GirlEditView({el : $("#edit_girl")}, this.variables);
}
});
//One girl from the list
Girl = Backbone.Model.extend({
initialize: function() {
this.view = new GirlView({el : $("#content")}, this.attributes );
}
});
//all the girls
Girls = Backbone.Collection.extend({
model: Girl,
});
//do magic!
$(document).ready(function() {
//Underscore template modification
_.templateSettings = {
escape : /\{\[([\s\S]+?)\]\}/g,
evaluate : /\{\[([\s\S]+?)\]\}/g,
interpolate : /\{\{([\s\S]+?)\}\}/g
}
//get initial data and fill the index
var list = [];
$.getJSON('girls.json', function(data) {
list = [];
$.each(data, function(key, val) {
list.push( new Girl(val) );
});
var myGirls = new Girls(list);
console.log( myGirls.models);
});
});
As you can see.
I'm using a collection to store all the girls and the data comes from a REST api in ruby.
Each girls create a new model instance and inside i attached a view instance.
I don't know if it's a good practice but i can't think a better way to do it.
Each view makes a content with a unique id. girl-1 girl-2 and go on.
Now, the template have a edit button.
My original idea is to attack the onclick event and trigger the edit view to get rendered.
That is working as expected.
The proble so far is:
When the events triggers, all the collection (girls) fire the edit view, not the one that "owns" the rendered view.
My question is what i'm doing wrong?
Thanks a lot

All the edit-views come up because all the GirlViews are using the same el:
this.view = new GirlView({el : $("#content")}, this.attributes );
and then you render be appending more HTML:
render: function() {
var template = _.template( $("#girl_template").html(), this.variables );
$(this.el).html( $(this.el).html() + template );
}
Backbone events are bound using delegate on the view's el. So, if multiple views share the same el, you'll have multiple delegates attached to the same DOM element and your events will be a mess of infighting.
You have things a little backwards: models do not own views, views watch models and collections and respond to their events. You'll see this right in the documentation:
constructor / initialize new View([options])
[...] There are several special options that, if passed, will be attached directly to the view: model, collection, [...]
Generally, you create a collection, c, and then create the view by handing it that collection:
var v = new View({ collection: c })
or you create a model, m, and then create a view wrapped around that model:
var v = new View({ model: m })
Then the view binds to events on the collection or model so that it can update its display as the underlying data changes. The view also acts as a controller in Backbone and forwards user actions to the model or collection.
Your initialization should look more like this:
$.getJSON('girls.json', function(data) {
$.each(data, function(key, val) {
list.push(new Girl(val));
});
var myGirls = new Girls(list);
var v = new GirlsView({ collection: myGirls });
});
and then GirlsView would spin through the collection and create separate GirlViews for each model:
var _this = this;
this.collection.each(function(girl) {
var v = new GirlView({ model: girl });
_this.$el.append(v.render().el);
});
Then, GirlView would render like this:
// This could go in initialize() if you're not certain that the
// DOM will be ready when the view is created.
template: _.template($('#girl_template').html()),
render: function() {
this.$el.html(this.template(this.model.toJSON());
return this;
}
The result is that each per-model view will have its own distinct el to localize the events. This also makes adding and removing a GirlView quite easy as everything is nicely wrapped up in its own el.

Related

Backbone.js View to render a list partially?

I plan to create a Backbone.js View for rendering a list of items. The list will grow. It seems to me that for performance reasons I should not empty and rebuild the DOM with the items. Does this make sense? How would you approach this?
My typical setup for this kind of thing is to use a define a Backbone.View for the ul or whatever containing element I have and bind that to a collection. Then define another Backbone.View to render a single list item. Instances of this view have a one-to-one relationship with the models in the collection.
Collections have different events that correspond nicely with the different types of DOM operations you would need to perform to reflect them. I map them like this:
sync = [render entire list on first fetch]
add = this.$append(...)
remove = [find corresponding list view item].remove()
OK, so this code is just hammered down from memory and not tested, but you get the idea:
var collection = new Backbone.Collection({
model: Backbone.Model,
url: '/some/api/endpoint'
});
var Li = Backbone.View.extend({
tagName: 'li',
initialize: function(){
this.render();
},
render: function(){
var template = _.template($('li-template').html());
this.el = template(model.toJSON());
}
});
var Ul = Backbone.View.extend({
collection:collection,
el: 'ul',
initialize: function(){
this.listItems = [];
this.collection.on('sync', this.addAll);
this.collection.on('add', this.addOne);
this.collection.on('remove', this.removeOne);
},
addAll: function(){
var frag = document.createDocumentFragment();
this.collection.forEach(function(model){
var view = new Li({model: model});
frag.appendChild(view.el);
this.listItems.push(view);
});
this.el.appendChild(frag);
},
addOne: function(model){
var view = new Li({model: model});
this.el.appendChild(view.el);
this.listItems.push(view);
},
removeOne: function(model){
for (var i = 0, num = this.listItems.length, item; i < num; i++) {
view = this.listItems[i];
if (view.model.cid === model.cid) {
this.el.removeChild(view.el);
this.listItems.splice(i, 1);
}
}
}
});

Backbone.js - delete views

This is my second day trying to use backbone and im completely lost. I am following this tutorial - http://net.tutsplus.com/tutorials/javascript-ajax/build-a-contacts-manager-using-backbone-js-part-3/
What I have done is loaded a contacts list and rendered it to the screen, but if you look at my render1 function - this takes a form input and appends it to my template. The problem is that I can't delete these items after they are created - the others can be deleted. help please?
var ContactView = Backbone.View.extend({
tagName: "contacts",
className: "contact-container",
template: $("#contactTemplate").html(),
initialize: function(){
this.model.on('change', this.render, this);
this.model.on('add', this.render1, this);
this.model.on('destroy', this.remove, this);
},
events: {
'click .deleteUser': 'delete'
},
test: function () {
alert("here");
},
delete: function () {
this.model.destroy();
},
render: function () {
console.log(this);
var tmpl = _.template(this.template);
$(this.el).html(tmpl(this.model.toJSON()));
temp = tmpl(this.model.toJSON());
console.log(temp);
return this;
},
render1: function () {
console.log(this);
var tmpl = _.template(this.template);
temp = tmpl(this.model.toJSON());
temp='<contacts class="contact-container">'+temp+'</contacts>';
console.log(temp);
$("#contacts").append(temp);
$(this.el).html(tmpl(this.model.toJSON()));
return this;
}
});
var AddPerson = Backbone.View.extend({
el: $("#addPerson"),
// el: $("form/"),
events: {
'click': 'submit',
'submit': 'submit'
},
submit: function(e) {
// alert("here");
e.preventDefault();
this.collection = new Directory();
// var data = (contacts[0]);
var contact = new Contact(contacts[0]);
var contactView = new ContactView({model: contact});
this.collection.add(contact);
this.collection.add(contactView);
}
});
seasick, there are quite a few issues in this code.
var contact = new Contact(contacts[0]);
var contactView = new ContactView({model: contact});
this.collection.add(contact);
this.collection.add(contactView);
Contact is a Backbone.Model but ContactView is a Backbone.View. Yet, you are adding both to the this.collection (which I assume is a Backbone.Collection of Contact?). See the problem here? In Backbone, there is no such concept of a 'collection of views'. You just get one concept: views, that are tied to a model.
So, here, you create a Contact and you add it to the Collection. That is all! It takes care of the Model part. The rendering part needs to be handled with events and renders.
When you add a model to a collection (this.collection.add(contact)), the collection will trigger a 'add' event, that you can hook to with a .on to create a new ContactView and append it to the DOM somewhere.
So when you write this...
this.model.on('add', this.render1, this);
You are actually saying 'When the Contact model triggers an add event, run render1', which isn't what you want, what you probably want is a collection.on('add', ...). The model will never trigger an add event (well, you could make it trigger one, but it wouldn't be an expected behavior!), the add/remove events are at the collection level.
In other words, you are missing some binding on the collection in your AddPerson view to 'react' to adding a new Contact to the collection. The code of the function bound to the add event should probably look a bit like:
onAdd: function(newContact){
var newContactView = new ContactView({model: newContact});
$("#contacts").append(newContactView.render().el);
}
There are other issues in your code, but I guess an outline of the steps to take would be like:
Remove the binding to add in ContactView: ContactView is only concerned with one contact, not how to manage multiple contacts. This is probably why you are having issues with only some (the first one?) of the contacts 'working'
Move that logic to the AddContact view which seems to be more concerned with the Collection of contacts. Use the collection 'add' event to create new ContactView and append them to the DOM
Hope this helps!

What is better way to store and access list of views in backbone.js?

I've been using backbone for quite some time now, and each time I get dynamic lists of views that have their own events and behaviors, I wonder how should they be stored. I've two ways and my thoughts on them are..
Store views internally in another view. This requires overhead in proper filtering, but is sort-of independent from DOM + might have better memory usage
Just generate views, put them in DOM and trigger events of views with jquery, like $('#someviewid').trigger('somecustomfunction'); - easier to write and access but dependencies are harder to see and I'm not certain that view/model gets deleted if I just remove DOM node
What would you recommend?
So here is expanded second example, where new views are just appended to internal html and storyViews themselves are forgotten. But If I want to access specific view from this list, I would have to use DOM attributes, like id or data and then trigger view functions with jquery accessors
Devclub.Views.StoriesList = Backbone.View.extend({
initialize: function () {
this.collection.bind('reset', this.reset, this);
this.collection.fetch();
},
reset: function (modelList) {
$(this.el).html('');
var me = this;
$.each(modelList.models, function (i, model) {
me.add(model);
});
},
add: function (model) {
var contact_model = new Devclub.Models.Story(model);
var view = new Devclub.Views.Story({
model: contact_model
});
var storyView = view.render().el;
$(this.el).append(storyView);
}
});
In contrast, I could instead store same view list in an array and iterate over it if I want to call some view methods directly
I think you should keep a reference of the child views. Here is an example from the book by Addy Osmani.
Backbone.View.prototype.close = function() {
if (this.onClose) {
this.onClose();
}
this.remove(); };
NewView = Backbone.View.extend({
initialize: function() {
this.childViews = [];
},
renderChildren: function(item) {
var itemView = new NewChildView({ model: item });
$(this.el).prepend(itemView.render());
this.childViews.push(itemView);
},
onClose: function() {
_(this.childViews).each(function(view) {
view.close();
});
} });
NewChildView = Backbone.View.extend({
tagName: 'li',
render: function() {
} });

How can I bind the model to the view?

When the view is initialized, how can I bind the model to the specific View that is created? The view is current initialized at the start of the application. Also, how can I bind the model to the collection?
(function ($) { //loads at the dom everything
//Creation, Edit, Deletion, Date
var Note = Backbone.Model.extend({
defaults: {
text: "write here...",
done: false
},
initialize: function (){
if(!this.get("text")){
this.set({"text": this.default.text});
}
},
edit: function (){
this.save({done: !this.get("done")});
},
clear: function (){
this.destroy();
}
});
var NoteList = Backbone.Collection.extend({
model:Note
});
var NoteView = Backbone.View.extend ({
el: "body",
initialize: function(){
alert("initialized");
var list = new NoteList;
return list;
},
events: {
"click #lol" : "createNote"
},
createNote : function(){
var note = new Note;
this.push(note);
alert("noted");
}
});
var ninja = new NoteView;
})(jQuery);
Update
I just took a look at #James Woodruff's answer, and that prompted me to take another look at your code. I didn't look closely enough the first time, but I'm still not sure what you're asking. If you're asking how to have a model or view listen for and handle events triggered on the other, then check out James's example of calling bind() to have the view listen for change (or change:attr) events on the model (although I'd recommend using on() instead of bind(), depending what version of Backbone you're using).
But based on looking at your code again, I've revised my answer, because I see some things you're trying to do in ways that don't make sense, so maybe that's what you're asking about.
New Answer
Here's the code from your question, with comments added by me:
var NoteView = Backbone.View.extend ({
// JMM: This doesn't make sense. You wouldn't normally pass `el`
// to extend(). I think what you really mean here is
// passing el : $( "body" )[0] to your constructor when you
// instantiate the view, as there can only be one BODY element.
el: "body",
initialize: function(){
alert("initialized");
// JMM: the next 2 lines of code won't accomplish anything.
// Your NoteList object will just disappear into thin air.
// Probably what you want is one of the following:
// this.collection = new NoteList;
// this.list = new NoteList;
// this.options.list = new NoteList;
var list = new NoteList;
// Returning something from initialize() won't normally
// have any effect.
return list;
},
events: {
"click #lol" : "createNote"
},
createNote : function(){
var note = new Note;
// JMM: the way you have your code setup, `this` will be
// your view object when createNote() is called. Depending
// what variable you store the NoteList object in (see above),
// you want something here like:
// this.collection.push( note ).
this.push(note);
alert("noted");
}
});
Here is a revised version of your code incorporating changes to the things I commented on:
var NoteView = Backbone.View.extend( {
initialize : function () {
this.collection = new NoteList;
},
// initialize
events : {
"click #lol" : "createNote"
},
// events
createNote : function () {
this.collection.push( new Note );
// Or, because you've set the `model` property of your
// collection class, you can just pass in attrs.
this.collection.push( {} );
}
// createNote
} );
var note = new NoteView( { el : $( "body" )[0] } );
You have to bind views to models so when a model updates [triggers an event], all of the corresponding views that are bound to the model update as well. A collection is a container for like models... for example: Comments Collection holds models of type Comment.
In order to bind a view to a model they both have to be instantiated. Example:
var Note = Backbone.Model.extend({
defaults: {
text: "write here..."
},
initialize: function(){
},
// More code here...
});
var NoteView = Backbone.View.extend({
initialize: function(){
// Listen for a change in the model's text attribute
// and render the change in the DOM.
this.model.bind("change:text", this.render, this);
},
render: function(){
// Render the note in the DOM
// This is called anytime a 'Change' event
// from the model is fired.
return this;
},
// More code here...
});
Now comes the Collection.
var NoteList = Backbone.Collection.extend({
model: Note,
// More code here...
});
Now it is time to instantiate everything.
var Collection_NoteList = new NoteList();
var Model_Note = new Note();
var View_Note = new NoteView({el: $("Some Element"), model: Model_Note});
// Now add the model to the collection
Collection_NoteList.add(Model_Note);
I hope this answers your question(s) and or leads you in the right direction.

Creating a backbone view for a collection

How can I bind a backbone view to a collection rather than a model? Do I need to wrap the collection in a model?
e.g.
If I have a backbone model Client and a collection of these called Clients
Client = Backbone.Model.extend({
defaults: {
Name: ''
}
});
Clients = Backbone.Collection.extend({
model: Client,
url: 'Clients'
});
and a view
var ClientListView = Backbone.View.extend({
template: _.template($("#clients-template").html()),
el: $('#clientlist'),
initialize: function() {
_.bindAll(this, 'render');
this.collection = new Clients();
},
render: function( event ){
$(this.el).html(this.template({ this.collection.toJSON()));
return this;
}
});
then I can't access each client element in the underscore template. However if I wrap the collection like this
$(this.el).html(this.template({ clients: this.collection.toJSON() }));
then I can. Is this the correct way to go about this? I would expect this to be a common scenario but I can't find any examples on it, am I going about it the wrong way?
Yes, you need to pass the wrapped collection.
Addy Osmani is using similar approach in his Backbone Fundamentals examples - see for example this view and corresponding template:
In the view:
$el.html( compiled_template( { results: collection.models } ) );
In the template:
<% _.each( results, function( item, i ){ %>
...
<% }); %>
Another alternative is to have a view that will create separate view for each model in the collection. Here is an example from An Intro to Backbone.js: Part 3 – Binding a Collection to a View:
var DonutCollectionView = Backbone.View.extend({
initialize : function() {
this._donutViews = [];
this.collection.each(function(donut) {
that._donutViews.push(new UpdatingDonutView({
model : donut,
tagName : 'li'
}));
});
},
render : function() {
var that = this;
$(this.el).empty();
_(this._donutViews).each(function(dv) {
$(that.el).append(dv.render().el);
});
}
});
You might want to take a look at backbone collectionView.

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