I am just getting into backbone.js and I thought the best way to get into it is to actually build a todo list (yea...pretty original). Humor aside, I have searched google and the docs and stackoverflow of course, for a way to add an attribute to a collection. So, in my case a todo list is a collection of listitems. However a Todo List can have a title as according to my design, I want to be able to create multiple lists.
var TodoList = Backbone.Collection.extend({
model: ListItem
});
//is this possible for collections?
var newTodoList = new TodoList({name: "My first list"});
Thanks a lot for the help! Appreciate it!
Yes, it's possible. Look at the signature of the Collection constructor:
new Collection([models], [options])
So you could write like this:
var ListItem = Backbone.Model.extend({});
var TodoList = Backbone.Collection.extend({
model: ListItem,
initialize: function(models, options) {
options || (options = {});
if (options.title) {
this.title = options.title;
};
}
})
var iPromise = new TodoList([], {
title: 'NY Resolutions'
})
console.log(iPromise.title);
Related
I am trying to nest a Collection View into a Model View.
In order to do so, I used Backbone's Marionnette Composite View and followed that tutorial
At the end he initializes the nested collection view like this:
MyApp.addInitializer(function(options){
var heroes = new Heroes(options.heroes);
// each hero's villains must be a backbone collection
// we initialize them here
heroes.each(function(hero){
var villains = hero.get('villains');
var villainCollection = new Villains(villains);
hero.set('villains', villainCollection);
});
// edited for brevity
});
How would you go doing the same without using the addInitalizer from Marionette?
In my project I am fectching data from the server. And when I try doing something like:
App.candidatures = new App.Collections.Candidatures;
App.candidatures.fetch({reset: true}).done(function() {
App.candidatures.each(function(candidature) {
var contacts = candidature.get('contacts');
var contactCollection = new App.Collections.Contacts(contacts);
candidature.set('contacts', contactCollection);
});
new App.Views.App({collection: App.candidatures});
});
I get an "indefined options" coming from the collection:
App.Collections.Contacts = Backbone.Collection.extend({
model: App.Models.Contact,
initialize:function(models, options) {
this.candidature = options.candidature;
},
url:function() {
return this.candidature.url() + "/contacts";
}
)};
That's because when you're creating the contactCollection, you're not providing a candidatures collections in an options object. You do need to modify your contact collection initialization code to something like:
initialize:function(models, options) {
this.candidature = options && options.candidature;
}
That way the candidature attribute will be set to the provided value (and if not provided, it will be undefined).
Then, you still need to provide the info when you're instanciating the collection:
App.candidatures.each(function(candidature) {
var contacts = candidature.get('contacts');
var contactCollection = new App.Collections.Contacts(contacts, {
candidature: candidature
});
candidature.set('contacts', contactCollection);
});
P.S.: I hope you found my blog post useful!
In my Application, I have the following JSON data format:
{
Item: {
property1: '',
...
}
}
Following the solution of this stackoverflow.com answer, I modeled my Backbond.js models the following way:
App.Models.Item = Backbone.Model.extend({
});
App.Models.ItemData = Backbone.Model.extend({
defaults: {
'Item': new App.Models.Item
}
});
I now want to bootstap the data to my App from the Backend system on the page load the following way:
var item = App.Models.ItemData({
{Item:
{property1: 'data'}
}
});
The problem I have now is that item.get('Item') returns a plain JavaScrip object and not a Backbone.Model object, because the defaults are overwritten. How can I create the Backbone.js object while ensuring that item.get('Item') is an App.Models.Item object?
I also have read that if you nest Backbone.Models, you should wirite custom getter methods, so the rest of your app dose not have to know about the internal data structure. If so, what is the right way to implement those setters and getters?
You can override the parse method on your ItemData model. No defaults required. The parse method will initialize an empty model, if one is not passed:
App.Models.ItemData = Backbone.Model.extend({
parse: function(attrs) {
attrs = attrs || {};
if(!(attrs.Item instanceof App.Models.Item))
attrs.Item = new App.Models.Item(attrs.Item);
return attrs;
}
});
And then initialize your ItemData model with the option parse:true:
var item = new App.Models.ItemData({Item:{property1: 'data'}}, {parse:true});
My Code:
I am new to Backbone.js and trying to build an app with Backbone.js and PHP. When I am trying to call add in the router, I am getting error:
Uncaught TypeError: Object [object Object] has no method 'set'.
Please help me to find my mistake.
Thanks.
// Models
window.Users = Backbone.Model.extend({
urlRoot:"./bb-api/users",
defaults:{
"id":null,
"name":"",
"email":"",
"designation":""
}
});
window.UsersCollection = Backbone.Collection.extend({
model:Users,
url:"./bb-api/users"
});
// Views
window.AddUserView = Backbone.View.extend({
template:_.template($('#new-user-tpl').html()),
initialize:function(){
this.model.bind("click", this.render, this);
},
render:function(){
$(this.el).html(this.template(this.model.toJSON()));
return this;
},
events:{
"click .add":"saveUser"
},
saveUser:function(){ alert('saveUser');
this.model.set({
name:$("#name").val(),
email:$("#email").val(),
designation:$("#designation").val()
});
if(this.model.isNew()){
this.model.create(this.model);
}
return false;
}
});
// Router
var AppRouter = Backbone.Router.extend({
routes:{
"":"welcome",
"users":"list",
"users/:id":"userDetails",
"add":"addUser"
},
addUser:function(){
this.addUserModel = new UsersCollection();
this.addUserView = new AddUserView({model:this.addUserModel});
$('#content').html(this.addUserView.render().el);
}
});
var app = new AppRouter();
Backbone.history.start();
As suggested in the comments, the problem starts here here:
this.addUserModel = new UsersCollection();
this.addUserView = new AddUserView({model:this.addUserModel});
and finishes here:
saveUser:function(){ alert('saveUser');
this.model.set({
By passing a collection in place of a model you create confusion, and as a result later in the saveUser function you try to call a Backbone.Model method (set) on a Backbone.Collection instance.
Note: As of version 1.0.0 Backbone.Collection now has a set method. In previous versions, such as the one used by the question's author, that method was instead called update.
There are several steps you can take to clarify this code. For starters, I would rename your model and collection classes so that it's clear that the model is the singular form and the collection is the plural form:
window.Users => window.User
window.UsersCollection => window.Users
Next, I would create a new User model, instead of a Users collection, and pass that to your view:
this.addUserModel = new User();
this.addUserView = new AddUserView({model:this.addUserModel});
Finally, I'd remove these lines:
if(this.model.isNew()){
this.model.create(this.model);
}
For one thing, the model will always be new (as you just created it before passing it in), but more importantly you don't need to call the Collection's create method because that method creates a new model, when you already have one created. Perhaps what you should add instead is :
this.model.save();
if your intent is to save the model to your server.
Since you already specified a urlRoot for the model, that should be all you need to create a new model, pass it to your view, have your view fill in its attributes based on DOM elements, and finally save that model's attributes to your server.
I think you are facing problem with object scope. When event fired it send to event object to that function. Just try this it may work
Declare global variable with the current view inside the initialize
initialize : function(){ self = this; }
then change this to self,
saveUser:function(){ alert('saveUser');
self.model.set({
name:$("#name").val(),
email:$("#email").val(),
designation:$("#designation").val()
});
if(self.model.isNew()){
self.model.create(this.model);
}
return false;
}
I have several views that have common code I'd like to abstract into a custom Backbone.View class. Is there any best practices for doing this?
is a good pattern to do something like this? :
// Base Grid view
var GridView = Backbone.View.extend({
initialize : function(){
//common view init code ..
//do the plug in overrides
if (options.addHandler)
this.addHandler = options.addHandler;
if (options.events)
//?? extend default events or override?
this.events = $.extend(this.events, options.events);
},
addHandler : function() {
//defaulthandler this code can be overridden
});
});
// in another object create some views from the GridView base
....
var overrides = { events:"xxx yyy", el: ulElement addHandler: myAddFunction }
var UserList = GridView.extend(overrides)
var userList = new UserList(users, options);
....
var coursesOverrides : {addHandler: ...}
var coursesOptions: {el: courseElement, ...}
var CourseList = GridView.extend(coursesOverrides)
var courseList= new CourseList (courses, coursesOptions)
// along the same lines maybe there's an abstraction for toolbar views
var ClassToolbarView = ToolbarBase.extend(toolOverrides)
var classtoolbar = new ClassToolbarView(actions, toolbaropts)
Any pointers to good examples of extending a View for refactoring common view code is appreciated.
First, I don't see the options being passed in your initializer(), so that's a bug.
Secondly, the .extend() method is inherited:
var GridView = Backbone.View.extend({ ... })
var GridViewWithNewFunctionsAndEvents = GridView.extend({ ... })
And you can replace or extend GridView's functionality, and call new GridViewWithNewFunctionsAndEvents() and get the extra functionality in a new object you need, just like you extend the Backbone stock View class.
If you need to extend the initializer, you can do this to call the initializer on the superclass:
var GridViewWithNewFunctionsAndEvents = GridView.extend({
initializer: function(options) {
GridView.prototype.initializer.call(this, options);
/* Your stuff goes here */
}
});
Currently when I insert a list of views in backbone I do :
var jqGuestList = $("#guestList");
jqGuestList.empty();
items.each(function(item){
var view = new wedapp.view.GuestItem({
model: item,
collection: this.collection
});
jqGuestList.append(view.render().el);
});
This however cause my a great deal of pain, adding each one manually to the DOM is slow as hell, specially on mobile but even on desktop..
is there a way to insert all the views in one jqGuestList.html(views) instead?
You could use a Document Fragment http://ejohn.org/blog/dom-documentfragments/
var jqGuestList = $("#guestList");
jqGuestList.empty();
var frag = document.createDocumentFragment();
items.each( function(item) {
var view=new wedapp.view.GuestItem({model:item});
frag.appendChild(view.render().el);
});
jqGuestList.append(frag);
You should see some improvement.