backbone model saving and callback issues - javascript

I just start using Backbone. I have two questions to ask based on the code below.
The first issue is after I fill out the form and click the button, the model object should be created with some default attributes. However, the console.log prints the model with the newest attribute from the form I fill out before I pass the model to the new view object.
The second issue is I can successfully save the data to db, but my success call back function is not being called. could someone help me to answer these questions??
var form = document.forms[0];
var RetailerModel = Backbone.Model.extend({
urlRoot: ' retailer.php',
defaults: {
name: 'company-name',
address: 'company-address',
phone: 'company-phone',
icon: 'http://localhost/icon.png'
}
});
var RetailerCollection = Backbone.Collection.extend({
});
var RetailerView = Backbone.View.extend({
className: 'retailer',
template: _.template($('#retailer-template').html()),
initialize: function() {
//this.listenTo(this.model, 'change', this.render);
var obj = {
name: form.name.value,
address: form.address.value,
phone: form.phone.value
};
this.model.set(obj);
//why the successful callback does not work????
this.model.save(null, {success: function(model, response){console.log('successful');}});
},
render: function() {
$('#retailer-list').append(this.$el.html(this.template(this.model.toJSON())));
return this;
}
});
var RetailerViews = Backbone.View.extend({
});
$('#submit').click(function(e){
var retailer_model = new RetailerModel();
console.log(retailer_model); // this prints out the new changed attributes instead of the default ones, why???
var retailer_view = new RetailerView({model: retailer_model});
form.reset();
});

1 Get the correct state of the model
console.log(retailer_model) will not show the models attributes, it'll show the whole model, but console.log(retailer_model.attributes) will. Also bear in mind that console.log isn't always on correct, especially if you modify the object just after you log it this can lead to confusion!
To get the actual current state of the model you should make a shallow or deep copy of it. So rather than console.log(model) you could use underscores clone method for a shallow copy:
console.log(_(model).clone());
2 Success Callback on Save
To help there we'd really need to know more about your circumstances. The first thing I'd look for is whether your server is returning the right feedback. Backbone is a system based on REST standards. Are you sure your server is returning the right response code? If you use chrome, open your developer tools and then the network tab to inspect what response you're getting when posting your model. In order for the success callback to be fired the server should return a status of 200 or 201.
Another way to test that is to see whether the error callback is firing :).

I tried to see your errors, I realized that you missed these things:
1. You should do DOM related things when DOM ready event fired:
$(function() {
form = document.forms[0];
$(form).live('submit', function(e){
// ...
});
});
2. You can use submit for forms. It catches also enter click within form:
$(form).live('submit',function(){
//...
});
3. You should use return false; within submit form. It prevents default form data sending to action url.
$(form).live('submit', function(e){
// ...
return false;
});
So, it looks like this. I didn't check success callback, but I hope it will work.
<html>
<head>
<script src="jquery-1.7.2.js" type="text/javascript"></script>
<script type="text/javascript" src="underscore.js"></script>
<script type="text/javascript" src="backbone.js"></script>
<script type="text/javascript">
var RetailerModel = Backbone.Model.extend({
urlRoot: ' retailer.php',
defaults: {
name: 'company-name',
address: 'company-address',
phone: 'company-phone',
icon: 'http://localhost/icon.png'
}
});
var RetailerCollection = Backbone.Collection.extend({});
var RetailerView = Backbone.View.extend({
className: 'retailer',
//template: _.template($('#retailer-template').html()),
initialize: function() {
//this.listenTo(this.model, 'change', this.render);
var obj = {
name: form.name.value,
address: form.address.value,
phone: form.phone.value
};
this.model.set(obj);
//why the successful callback does not work????
this.model.save(null, {
success: function(model, response){
console.log('successful');
}
});
},
render: function() {
$('#retailer-list').append(this.$el.html(this.template(this.model.toJSON())));
return this;
}
});
var RetailerViews = Backbone.View.extend({});
$(function() { // you should do DOM related things when DOM ready event fired
form = document.forms[0];
$(form).live('submit', function(e){
var retailer_model = new RetailerModel();
console.log(retailer_model);
var retailer_view = new RetailerView({model: retailer_model});
form.reset();
return false; // to prevent form data sending return false
});
});
</script>
</head>
<body>
<form action="#" id="#submit">
<input type="submit" value="submit"/>
<input type="text" name="address"/>
<input type="text" name="name"/>
<input type="text" name="phone"/>
</form>
</body>
</html>

Related

Backbone.js primer customisation issues

I've been trying to get my first Backbone.js app up and running, following the Backbone.js primer here.
I've followed the example through and now I'm trying to customise it for my purposes which are to simply retrieve and read a JSON file from my server. I don't need to be able to change or delete any of the data.
I've set up my html as per the primer below:
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
<title>Backbone.js Primer</title>
<script type="text/javascript" src="./node_modules/jquery/dist/jquery.min.js"></script>
<script type="text/javascript" src="./node_modules/underscore/underscore-min.js"></script>
<script type="text/javascript" src="./node_modules/backbone/backbone-min.js"></script>
<script type="text/javascript" src="./node_modules/moment/moment.js"></script>
<script type="text/javascript" src="./backbone.js"></script>
</head>
<body>
<div>
<h1>Transcripts Data</h1>
<div id="dailyTranscripts-app">
<ul class="dailyTranscripts-list"></ul>
</div>
</div>
</body>
</html>
I've then coded my backbone.js file as the primer describes below:
var yesterday = moment (new Date()).add(-1, 'days').format('YYYY-MM-DD')
var yesterdaysDataURL = 'https://mihndbotblob.blob.core.windows.net/mihndbot-transcripts/finalTranscripts/dailyTranscripts/' + yesterday + '.json'
// Model class for each transcript iten
var DailyTranscriptsModel = Backbone.Model.extend({
defaults: {
type: null,
MessageID: null,
MessageTime: null,
MessageChannel: null,
MessageSenderID: null,
MessageSenderName: null,
ConversationID: null,
MessageText: null,
MessageRecipientID: null,
QuickReplyDisplayText: null,
QuickReplyPayload: null,
Question: null,
Answer: null,
FollowUpPrompts: null
}
});
// Collection class for the DailyTransctipts list endpoint
var DailyTranscriptsCollection = Backbone.Collection.extend({
model: DailyTranscriptsModel,
url: yesterdaysDataURL
});
// View class for displaying each dailyTranscripts list item
var DailyTranscriptsListItemView = Backbone.View.extend({
tagName: 'li',
className: 'dailyTranscripts',
initialize: function () {
this.listenTo(this.model)
},
render: function () {
var html = '<b>Message ID: </b> ' + this.model.get('MessageID');
html += '<br><b>Message Time: </b>' + this.model.get('MessageTime');
this.$el.html(html);
return this;
}
});
// View class for rendering the list of all dailyTranscripts
var DailyTranscriptsListView = Backbone.View.extend({
el: '#dailyTranscripts-app',
initialize: function () {
this.listenTo(this.collection, 'sync', this.render);
},
render: function () {
var $list = this.$('ul.dailyTranscripts-list').empty();
this.collection.each(function (model) {
var item = new DailyTranscriptsListItemView({model: model});
$list.append(item.render().$el);
}, this);
return this;
}
});
// Create a new list collection, a list view, and then fetch list data:
var dailyTranscriptsList = new DailyTranscriptsCollection();
var dailyTranscriptsView = new DailyTranscriptsListView({collection: dailyTranscriptsList });
dailyTranscriptsList.fetch();
The major changes I've made to the code (apart from some customisations) are to remove the templates the primer uses to create the views (I couldn't get them working) and I've removed the Backbone CRUD elements as I only require my app to read data from the server, not update or delete it.
The issue I have is that whilst I'm pulling back the JSON file from the server, none of the data is rendering in the HTLM <div> as expected, it's just blank.
I know that Backbone.js is retrieving the data as when I add .then(function() {console.log(dailyTranscriptsList);}); to the final dailyTranscriptsList.fetch() call I can see the data in the browser console:
You need to wrap all of your backbone.js code within jQuery's .ready()
// backbone.js
$(document).ready(function () {
// all your backbone.js code here
})
This causes your js to run after the DOM is ready, so Backbone will know how to find the elements it needs in order for views to work.
You could also move <script type="text/javascript" src="./backbone.js"></script> to the end of the page, right before </body>

How can I integrate handlebars with backbone

I have a simple single page application which is for my own learning. The page has a UL of all the services that I provide. This list comes from a JSON. Next to each service there is a price for it, and a check-box which the user can select if he needs the service.
Under the list there is a total price value for all the services selected. Based on this, can you please tell me what wrong am I doing? I am trying to integrate the list of services as a handlebar template.
Here is the HTML
<head>
<meta charset="utf-8" />
<title>Your first Backbone.js App | Tutorialzine </title>
<!-- Google web fonts -->
<link href="http://fonts.googleapis.com/css?family=PT+Sans:400,700" rel='stylesheet' />
<!-- The main CSS file -->
<link href="http://localhost/backbone-demo/assets/css/style.css" rel="stylesheet" />
</head>
<body>
<form id="main" method="post" action="submit.php">
<h1>My Services</h1>
<div id="serviceTable"></div>
<ul id="services">
<script id="services-template" type="text/x-handlebars-template">
<!-- The services will be inserted here via handlebars-->
{{#each services}}
<li>
<input type="checkbox" value="1" name="{{title}}"/> {{title}}
<span>${{price}} </span>
</li>
{{/each}}
</script>
</ul>
<p id="total">total: <span>$0</span></p>
<input type="submit" id="order" value="Order" />
</form>
<!-- JavaScript Includes -->
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
<script src="http://localhost/backbone-demo/assets/js/libs/underscore.min.js"></script>
<script src="http://localhost/backbone-demo/assets/js/libs/backbone.min.js"></script>
<script src="http://localhost/backbone-demo/assets/js/libs/handlebars.js"></script>
<script src="http://localhost/backbone-demo/assets/js/script.js"></script>
</body>
Here is the Javascript:
$(function(){
// Create a model for the services
var Service = Backbone.Model.extend({
// Will contain three attributes.
// These are their default values
defaults:{
title: 'My service',
price: 100,
checked: false
},
// Helper function for checking/unchecking a service
toggle: function(){
this.set('checked', !this.get('checked'));
}
});
// Create a collection of services
var ServiceList = Backbone.Collection.extend({
// Will hold objects of the Service model
model: Service,
// Return an array only with the checked services
getChecked: function(){
return this.where({checked:true});
}
});
//Retrieve the list of services
$.ajax({
type: "GET",
url: "assets/services.json",
async: true,
success: function(response){
// Prefill the collection with a number of services.
var services = new ServiceList(response);
var ServiceView = Backbone.View.extend({
tagName: 'li',
events:{
'click': 'toggleService'
},
initialize: function(){
// Set up event listeners. The change backbone event
// is raised when a property changes (like the checked field)
this.listenTo(services, 'change', this.render);
},
render: function(){
var tpl = Handlebars.compile($("#services-template").html());
//console.log(this.$el.selector);
this.$el.html(tpl({services: services.toJSON()}));
//console.log(this.$el);
$('#serviceTable').append(this.$el);
//document.getElementById('serviceTable').innerHTML = serviceData;
// Create the HTML
/* this.$el.html('<input type="checkbox" value="1" name="' + this.model.get('title') + '" /> ' + this.model.get('title') + '<span>$' + this.model.get('price') + '</span>');
this.$('input').prop('checked', this.model.get('checked')); */
// Returning the object is a good practice
// that makes chaining possible
return this;
},
toggleService: function(){
this.model.toggle();
}
});
// The main view of the application
var App = Backbone.View.extend({
// Base the view on an existing element
el: $('#main'),
initialize: function(){
// Cache these selectors
this.total = $('#total span');
this.list = $('#services');
// Listen for the change event on the collection.
// This is equivalent to listening on every one of the
// service objects in the collection.
this.listenTo(services, 'change', this.render);
// Create views for every one of the services in the
// collection and add them to the page
services.each(function(service){
var view = new ServiceView({ model: service });
this.list.append(view.render().el);
}, this); // "this" is the context in the callback
},
render: function(){
// Calculate the total order amount by agregating
// the prices of only the checked elements
var total = 0;
console.log(services.getChecked());
Handlebars.each(services.getChecked(), function(elem){
console.log(total);
total += elem.get('price');
});
// Update the total price
this.total.text('$'+total);
return this;
}
});
new App();
}
});
});
Below is a workable snippet of your code. You have defined a ServiceView, which is created for each service in your set, however within this view, you are working with the collection as a whole, not this.model and your handlebars template has a for loop in it.
This means that you end up displaying the collection as many times as there are models in the collection. The example below duplicates the list twice as there are 2 records in the list.
There are 2 possible solutions:
Rename your ServiceView to ServicesView and remove the loop within App initialize.
Remove the loop in your template and change the call to this.$el.html(tpl(this.model.toJSON()));
// Create a model for the services
var Service = Backbone.Model.extend({
// Will contain three attributes.
// These are their default values
defaults:{
title: 'My service',
price: 100,
checked: false
},
// Helper function for checking/unchecking a service
toggle: function(){
this.set('checked', !this.get('checked'));
}
});
// Create a collection of services
var ServiceList = Backbone.Collection.extend({
// Will hold objects of the Service model
model: Service,
// Return an array only with the checked services
getChecked: function(){
return this.where({checked:true});
}
});
//Retrieve the list of services
$.ajax({
type: "GET",
url: "http://www.mocky.io/v2/588b429d300000d11afa8d97",
async: true,
success: function(response){
// Prefill the collection with a number of services.
var services = new ServiceList(response);
var ServiceView = Backbone.View.extend({
tagName: 'li',
events:{
'click': 'toggleService'
},
initialize: function(){
// Set up event listeners. The change backbone event
// is raised when a property changes (like the checked field)
this.listenTo(services, 'change', this.render);
},
render: function(){
var tpl = Handlebars.compile($("#services-template").html());
//console.log(this.$el.selector);
this.$el.html(tpl({services: services.toJSON()}));
//console.log(this.$el);
$('#serviceTable').append(this.$el);
//document.getElementById('serviceTable').innerHTML = serviceData;
// Create the HTML
/* this.$el.html('<input type="checkbox" value="1" name="' + this.model.get('title') + '" /> ' + this.model.get('title') + '<span>$' + this.model.get('price') + '</span>');
this.$('input').prop('checked', this.model.get('checked')); */
// Returning the object is a good practice
// that makes chaining possible
return this;
},
toggleService: function(){
this.model.toggle();
}
});
// The main view of the application
var App = Backbone.View.extend({
// Base the view on an existing element
el: $('#main'),
initialize: function(){
// Cache these selectors
this.total = $('#total span');
this.list = $('#services');
// Listen for the change event on the collection.
// This is equivalent to listening on every one of the
// service objects in the collection.
this.listenTo(services, 'change', this.render);
// Create views for every one of the services in the
// collection and add them to the page
services.each(function(service){
var view = new ServiceView({ model: service });
this.list.append(view.render().el);
}, this); // "this" is the context in the callback
},
render: function(){
// Calculate the total order amount by agregating
// the prices of only the checked elements
var total = 0;
console.log(services.getChecked());
Handlebars.each(services.getChecked(), function(elem){
console.log(total);
total += elem.get('price');
});
// Update the total price
this.total.text('$'+total);
return this;
}
});
new App();
}
});
<form id="main" method="post" action="submit.php">
<h1>My Services</h1>
<div id="serviceTable"></div>
<ul id="services">
<script id="services-template" type="text/x-handlebars-template">
<!-- The services will be inserted here via handlebars-->
{{#each services}}
<li>
<input type="checkbox" value="1" name="{{title}}"/> {{title}}
<span>${{price}} </span>
</li>
{{/each}}
</script>
</ul>
<p id="total">total: <span>$0</span></p>
<input type="submit" id="order" value="Order" />
</form>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.8.3/underscore-min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/backbone.js/1.3.3/backbone-min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/handlebars.js/4.0.6/handlebars.min.js"></script>

Automatic two way binding with Knockout

I'm just getting started with Knockout.js and i have a view(html) which is supposed to be populated by data from a rest api via jquery's $.getJSON method.
When i run the app, nothing shows but using firebug i can see that the 'GET' query returns a status code of 200 and the right data.
I'm at a fix as to why nothing shows in the view since the bindings in Knockout.js are supposed to be automatic.
Below is my code.
Thanks
<div id ='main'>
<!-- ko foreach: posts -->
<p>Hello</p><span data-bind="text: title"></span></p><p data-bind="text: content"></p>
<p data-bind="text: author"></p><p data-bind="text: date"></p>
<!-- /ko -->
</div>
</body>
<script type="text/javascript">
function Post(data){
this.title = ko.observable(data.title);
this.content = ko.observable(data.content);
this.author = ko.observable(data.author);
this.date = ko.observable(data.date)
}
function PostListViewModel(){
var self = this;
self.posts = ko.observableArray([]);
$.getJSON("/posts", function(getPost){
var mappedPost = $.map(getPost, function(item){
return new Post(item)
});
self.posts(mappedPost);
});
}
var postlistviewmodel = new PostListViewModel();
ko.applyBindings(postlistviewmodel);
</script>
This should be:
$.getJSON("/posts", function(getPost){
var mappedPosts = $.map(getPost, function(item){
return new Post(item)
});
self.posts(mappedPosts);
});
wouldn't do self.posts.push(mappedPosts[i]) at all. You should just pass mappedPosts through the ko binding in order to update the listeners.
If your just getting the latest posts and want to update your current list simply do:
var allPosts = self.posts().concat(mappedPosts);
self.posts(allPosts);
You don't need the model to have ko.observable if you're just displaying them. If you want to edit model as well, then leave as.
Also, I tend to do this for single or multiple view models:
ko.applyBindings({viewModel : new viewModel() };
This allows for having multiple named view models. Access scope using: $root.viewModel
This is what I did earlier: http://jsfiddle.net/jFb3X/
Check your code against this fiddle then.
Script tags also need to be above the closing body tags
<html>
<head>
</head>
<body>
<!-- all your html content -->
<script type="text/javascript">
var viewModel = function () {
}
ko.applyBindings({viewModel : new viewModel()});
</script>
</body>
</html>
Is it something as simple as waiting for the DOM to be ready?
Are you able to try the following:
$(function () {
ko.applyBindings(postlistviewmodel);
});
Source: I've done this a few times and been stumped for a bit trying to see what I did wrong. :-)
(As a style thing, I'd also move the /body to after the /script - probably not related to your issue though).
I suspect you get multiple posts from /posts. You only push a single item (array).
...
$.getJSON("/posts", function(getPost){
var mappedPosts = $.map(getPost, function(item){
return new Post(item)
});
for(var i = 0; i < mappedPosts.length; i++) {
self.posts.push(mappedPosts[i]);
}
});
...

Backbone View not rendering after fetch is successful

I'm new to Backbone and trying to put together a small app and having problems getting a view to render client side.
Here is my client html in jade.
extends layout
block content
.row
#breadcrumbs.span12
script#room-list-template(type="text/template")
<td><%=name%></td>
<td><button class="btn btn-info">Join Room</button></td>
script(src="/javascripts/dislocated_poker/index.js").
script(src="/javascripts/dislocated_poker/nav.js").
script(src="/javascripts/dislocated_poker/room.js").
script(type="text/javascript").
$(function(){
DislocatedPoker.init();
})
This call my init function to fetch the data which is stashed away in MongoDb
DislocatedPoker = {
init : function() {
var crumbView = new DislocatedPoker.BreadcrumbView({el : "#breadcrumbs"});
crumbView.render();
var rooms = new DislocatedPoker.Rooms();
var roomListView = new DislocatedPoker.RoomListView({collection : rooms});
rooms.fetch();
}
};
And here are my views and models.
DislocatedPoker.Room = Backbone.Model.extend({
});
DislocatedPoker.Rooms = Backbone.Collection.extend({
model : DislocatedPoker.Room,
url : "/api/rooms"
});
DislocatedPoker.RoomView = Backbone.View.extend({
tagName : "tr",
render : function() {
var template = $("#room-list-template").html();
var compiled = _.template(template, this.model.toJSON());
$(this.el).html(compiled);
return this;
}
})
DislocatedPoker.RoomListView = Backbone.View.extend({
initialize : function() {
this.collection.bind("reset", this.render, this);
this.collection.bind("add", this.render, this);
},
tagName : "table",
className : "table table-striped",
render : function() {
var els = [];
this.collection.each(function(item) {
var itemView = new DislocatedPoker.RoomView({model : item});
els.push(itemView.render().el);
})
//return this;
$(this.el).html(els);
$("#room-list").html(this.el);
}
})
I see JSON being returned from the fetch() method and the collection is iterated, but the result never ends up as client html. If I view the source of the HTML I see the following where the template should render.
<script id="room-list-template" type="text/template"><td><%=name%></td>
<td><button class="btn btn-info">Join Room</button></td>
I feel like I am missing something pretty obvious but can't seem to pinpoint the issue.
Any guidance is much appreciated.
Thanks.
It looks like the following won't work:
$(this.el).html(els);
jQuery's html function takes a string, you're providing an array. Try with:
$(this.el).html(els.join(""));
You should try the following:
this.collection.bind("fetched", this.render, this);

backbone collection. fetch() not rendering the view in mozilla

i am trying to learn backbone.js ( Backbone.js 1.0.0) this is my sample html page where iam using collection. fetch() method to get the collection,and it is displayed using view .i am getting result in
google chrome,but nothing is displayed in mozilla. i don't know the exact reason.
while i refere to backone site http://backbonejs.org/#Collection-fetch
it is qouted that :
Note that fetch should not be used to populate collections on page load — all models needed at load time should already be bootstrapped in to place. fetch is intended for lazily-loading models for interfaces that are not needed immediately: for example, documents with collections of notes that may be toggled open and closed.
is this is related with my issue?
this is my sample html page
<!DOCTYPE html>
<html>
<head>
<title>Backbone Application</title>
<script src="js/jquery.js" type="text/javascript"></script>
<script src="js/underscore.js" type="text/javascript"></script>
<script src="js/backbone.js" type="text/javascript"></script>
</head>
<body>
<div class="list"></div>
<script id="personTemplate" type="text/template">
<td> <strong><%= name %></strong></td>
<td>(<%= age %>) </td>
<td> <%= occupation %> </td>
</script>
<script type="text/javascript">
//Person Model
var Person = Backbone.Model.extend({
defaults: {
name: 'Guest User',
age: 30,
occupation: 'worker'
}
});
// A List of People
var PeopleCollection = Backbone.Collection.extend({
model: Person,
initialize: function(){
alert("intialise")
},
url:'/RestFul/rest/members/info',
});
// View for all people
var PeopleView = Backbone.View.extend({
tagName: 'table',
render: function(){
this.collection.each(function(person){
var personView = new PersonView({ model: person });
this.$el.append(personView.render().el); // calling render method manually..
}, this);
return this; // returning this for chaining..
}
});
// The View for a Person
var PersonView = Backbone.View.extend({
tagName: 'tr',
template: _.template($('#personTemplate').html()),
////////// initialize function is gone from there. So we need to call render method manually now..
render: function(){
this.$el.html( this.template(this.model.toJSON()));
return this; // returning this from render method..
}
});
var peopleCollection = new PeopleCollection();
//peopleCollection.fetch();
peopleCollection.fetch({ success: function () { console.log("collection fetched"); } });
//peopleCollection.fetch({context:collection}).done(function() {
// console.log(this.length)
// })
//console.log(peopleCollection.toJSON())
alert(JSON.stringify(peopleCollection));
var peopleView = new PeopleView({ collection: peopleCollection });
$(document.body).append(peopleView.render().el); // adding people view in DOM
</script>
</body>
</html>
any help will be appreciated
Try with
var fetching = peopleCollection.fetch({ success: function () { console.log("collection fetched"); } });
$.when(fetching).done(function(){
var peopleView = new PeopleView({ collection: peopleCollection });
$(document.body).append(peopleView.render().el); // adding people view in DOM
});
var fetching = peopleCollection.fetch({ success: function () {
var peopleView = new PeopleView({ collection: peopleCollection });
$(document.body).append(peopleView.render().el);
} });
I think we can call the view render inside the success callback

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