The Backbone documentation for collections shows example where you set parse when collection is defined.
var Tweets = Backbone.Collection.extend({
// The Twitter Search API returns tweets under "results".
parse: function(response) {
return response.results;
}
});
But, is there a way to set a function for parse after a Backbone collection has been instantiated?
this.collection.parse = function (response) {
return response.results;
};
this.collection.fetch();
Related
In that rest api url, i am getting an json array and have fetch it with EmployeeList collection. using the fetch() only call the rest api. If I didnt use the fetch, the rest api call doesnt work, it tested using the log in api-code. while fetching I get all the details, but I am getting the error,
Uncaught TypeError: this.model is not a constructor backbone-min.js:24
I am new to the backbonejs. Whats the error, why this error will happens. My code is below,
var app = {};
app.Employee = Backbone.Model.extend();
app.employee = new app.Employee();
app.EmployeeList = Backbone.Collection.extend({
model: app.employee,
url:'/api/employ',
parse: function(response) {
return response;
}
})
app.employeeList = new app.EmployeeList();
app.employeeList.fetch();
app.AppView = Backbone.View.extend({
el: '#emp',
initialize: function(){
this.render();
console.log(app.employeeList);
},
render: function(){
this.$el.html('sathish');
}
});
app.appView = new app.AppView();
Change
app.EmployeeList = Backbone.Collection.extend({
model: app.employee,
.....
})
To
app.EmployeeList = Backbone.Collection.extend({
model: app.Employee,
...
})
the model param should be a model class(a constructor function in js) like app.Employee.
You should provide app.Employee() instead of new app.Employee() as a model parameter of the collection.
I've model with a parse function
var File = Backbone.Model.extend({
...
parse: function(response) {
console.log('Parsing response')
}
});
var FileView = Backbone.View.extend({
...
initialize: function(id) {
this.file = new File({id: id.id});
console.log('Fetching object')
this.file.fetch();
this.render();
},
render: function() {
console.log('Rendering view');
this.$el.html(this.template(this.file.JSON()));
}
})
The expected result would be:
Fetching object
Parsing response
Rendering view
But this is what I got:
Fetching object
Rendering view
Parsing response
Why is this? According to the docs:
parse is called by Backbone whenever a collection's models are
returned by the server, in fetch.
Why isn't the parse function called directly after fetching the model? How force it to do this?
Yeah, but you're making an async call to the server to fetch the model, so render is actually being called before you get answer. You have to do, something like this:
this.file.fetch({success: function () {
//call render here
}});
i'm trying to connect model and collection using parse.com but i'm confused. I'm tring to fetch by collection using backbone and javascript api parse.com but compare this error:POST https://api.parse.com/1/classes 404 (Not Found).
Model:
var Person = Backbone.Model.extend({
defaults:{
},
initialize:function(){
console.log("inperson");
this.validate();
this.send();
},
validate:function(){
console.log("validate");
},
send:function(){
var user = new Parse.User();
user.set("username", this.get("username"));
user.set("password", this.get("password"));
user.set("email", this.get("email"));
user.signUp(null, {
success: function(user) {
// Hooray! Let them use the app now.
},
error: function(user, error) {
// Show the error message somewhere and let the user try again.
alert("Error: " + error.code + " " + error.message);
}
});
}
});
return Person;
});
Collection:
var Usercollection = Parse.Collection.extend({
model:Person,
initialize:function(){
}
});
return Usercollection;
});
and finally the view that call the colletion and fetch:
var HomeView = Backbone.View.extend({
template: Handlebars.compile(template),
events: {
},
initialize: function() {
console.log("inhomeview");
var amici = new Usercollection();
amici.fetch({
success: function(collection) {
amici.each(function(object) {
console.warn(object);
});
},
error: function(amici, error) {
// The collection could not be retrieved.
}
});
},
render: function() {
}
});
return HomeView;
});
Cant you just swap the backbone collection and model to Parse's ones? (You only used the Parse type of the collection, not the model!)
Try switch that Backbone model to a Parse.Object .
Step by step below:
First of all Lets create a new app on Parse.com, mine is called FunkyAppartments.
Insert the script tag for loading Parse javascript lib into index.html or whathever:
<script src="http://www.parsecdn.com/js/parse-1.5.0.min.js"></script>
Switch the backbone model and collection to use parse types instead (and rename the fetch method if you have extended backbones, since we do not want to overide the one of parse):
//var Appartment = Backbone.Model.extend(); Backbone wo. Parse.com
var Appartment = Parse.Object.extend("Appartment");
//var Appartments = Backbone.Collection.extend({ Backbone wo. Parse.com
var Appartments = Parse.Collection.extend({
model: Appartment,
loadAppartments: function(callback){
debugger;
this.query = new Parse.Query(Appartment);
this.fetch();
}
});
I added a debugger tag in the load appartments so that developer tools breaks in the middle of the controller, here I have access to the Appartment private type of the controller, hence i can store some data on the parse server and verify by pasting the below in the developer tools console.
var testAppartment = new Appartment();
testAppartment.save({name: "foobars"}).then(function(object) {
alert("yay! it worked");
});
Yei, the data shows up in the parse.com UI for the app we just added there. And more importantly it shows up in our frontend. That was easy!
UPDATE: PROBLEMS W BACKBONE 1.2.1, MARIONETTE 2.4.2, UNDERSCORE 1.8.3
I noticed that I actually had been using old versions of marionette, backbone and underscore.js. An initial update appeared to break the application.
After some research i found that it was the parse part that did not return objects that would successfully render. Hence I changed the collection type back to an extension of: Backbone.collection instead of Parse.collection.
I also had to override the query method, since the objects would not save on the correct id, updating an object resulted in a new object being added instead of an old one being updated.
var Apartment = Parse.Object.extend('Appartment');
var Apartments = Backbone.Collection.extend({
model: Apartment,
query: new Parse.Query(Apartment),
initialize: function(){
MyApp.vent.on('search:param', function(param){self.search(param); });
var self = this;
this.query.find({
success: function(results){
self.reset();
results.forEach(function(result){
result.attributes.id__ = result.id
var ap = new Apartment(result.attributes);
self.add(ap);
});
}
});
}
});
I added an attribute: id__ to hold the parse id (naming it just id did not work since it backbone interfered with it, making it disappear).
Finally in saving the model to parse i utilized id__ as id in the save call:
var ApartmentEditView = Backbone.Marionette.ItemView.extend({
template: "#apartment-edit-template",
className: "apartmentDetail",
events: {
"click .store": "storeEdit",
"click .close": "closeEdit"
},
storeEdit: function(){
var priceNum = Number($('#price_field').val().replace(/\s/g, ''));
this.model.set({
id: this.model.attributes.id__,
name:$('#name_field').val(),
price:priceNum,
description:$('#desc_field').val(),
url:$('#url_field').val()
});
this.model.save();
this.closeEdit();
},
closeEdit: function(){
var detailView = new ApartmentDetailView({model: this.model});
MyApp.Subletting.layout.details.show(detailView);
}
});
Now the object is updated correctly in the database.
I am very new to backbone.js, to try it out I made a function to append an element using my array. But I don't know how to fetch the same from server or my local path.
I tried with some tutorial but still I couldn't get any good result. Can any one correct my function to fetch the data from local folder or server?
code :
this is my local path: '..data/data.json'
(function($){
var student = [
{name:'student1'},
{name:'student2'},
{name:'student3'}
]
var model = Backbone.Model.extend({
defaults:{
name:'default name'
}
});
var collection = Backbone.Collection.extend({
model:model
});
var itemViews = Backbone.View.extend({
tagname:'li',
render:function(){
this.$el.html(this.model.get('name'));
return this;
}
})
var view = Backbone.View.extend({
el: $("#contacts"),
initialize:function(){
this.collection = new collection(student);
this.render();
},
render:function(){
var that = this;
_.each(this.collection.models, function(item){
that.renderName(item);
})
},
renderName:function(item){
var itemView = new itemViews({model:item});
this.$el.append(itemView.render().el);
}
});
Collections have the url property which links to the url where the models can be fetched (in a proper JSON format of course).
If you have a RESTful API you can tie them directly to a collection on your backend.
In your case you can modify the collection definition as follows
var collection = Backbone.Collection.extend({
model:model,
url: '..data/data.json' //OR WHATEVER THE URL IS
});
Then when instantiating your collection you have to call the fetch() method to fill in the collection.
myCollection = new collection();
myCollection.fetch();
For more information see this post
Backbone will call GET, POST, DELETE, etc on that same url depending on what needs to be sent or received from the server. So if you are building the REST api, your controller or router should route the appropriate functions to those methods. See below for exact mapping:
create → POST /collection
read → GET /collection[/id]
update → PUT /collection/id
delete → DELETE /collection/id
As a side note, if you have no control over the JOSN that is returned from the server, you can format it in any format you like in the parse function.
parse: function(response) { return response.itemYouWantAdded; }
This would be the case if your server is returning an object within an object, such as twitter feeds.
Or you could simply populate the model from the response manually in the parse function
parse: function(response) { var tmpModel = {
item1:response.item1,
item2:response.item2
};
return tmpModel; }
Hope this helps.
You can set a URL for your model or for your collection. Then when you run fetch it will read your JSON straight into either a single model or a collection of models. So in your case, your collection might look like
var collection = Backbone.Collection.extend({
url: '..data/data.json',
model: model
});
collection.fetch(); // Could also use collection.reset()
You just need to make sure your JSON is formatted properly to match your model's attributes.
I'm trying to return JSON output from a Laravel route. Here's my route:
Route::get('main-contact-count', function() {
$mc = MainContact::where('flag', '=', '1')->count();
return Response::json(['count' => $mc]);
});
If I look at the response tab in Firebug, I'm getting back:
{"count":9}
The JSON encoding is missing the square brackets. This JSON is different than the JSON Laravel returns from a resourceful controller. It has the square brackets. Backbone parses it fine. Backbone doesn't parse the above JSON correctly. If you look at the length and models when you console.log a collection, they're both zero. You can, however, drill down into the object and you can find a count property set to 9.
How do I get the correct JSON out of Laravel?
Just for kicks and giggles, I'm posting my Backbone, in case I'm doing something hinky there:
App.Collections.Count = Backbone.Collection.extend({
model: App.Models.Count,
initialize: function(models, options) {
this.fetch({
success: function(data, options) {
// console.log(data.models);
}
});
if (options) {
this.url = this.url || options.url;
}
}
});
App.Views.Count = Backbone.View.extend({
tagName: 'span',
className: 'leadCount',
template: _.template($('#contactCount').html()),
initialize: function() {
},
render: function() {
this.$el.html(this.template(this.collection.toJSON()));
return this;
}
});
And in my route:
var mc = new (App.Collections.Count.extend({ url: 'main-contact-count' }))();
var mcv = new (App.Views.Count.extend({ collection: mc }))();
The JSON response sent by your service is a single JSON object ({...}) Your collection is not able to parse it because it expects an array of JSON objects ([{...}, {...}]).
If I've understood your code correctly, /main-contact-count is a specialized service whose function is to return and single datum: a count of contacts. If this is the case, Backbone.Collection may not be the correct solution. Collections are meant for... well, collections of things.
You should use just a model instead:
App.Models.Count = Backbone.Model.extend({
url:'main-contact-count'
});
var countModel = new App.Models.Count();
countModel.fetch({success: function(model, resp) {
var count = model.get('count');
});
Or even better, forego Backbone altogether and just fetch the data using jQuery:
$.getJSON('main-contact-count', function(response) {
var count = response.count;
});
try:
return Response::json(array(array('count' => $mc));