I'm trying to get tweets to pull from a URL, which returns data in the form of:
[
{"user":"someuser1","tweet":"this is a #tweet","date":"2011-09 02"},
{"user":"someuser2","tweet":"and this is a #tweet","date":"2011-09 02"},
{"user":"someuser3","tweet":"and this is another #tweet","date":"2011-09"}
]
I have a model,
window.Tweet = Backbone.Model.extend({
initialize: function(){
this.bind('change',function(){
})
},
defaults: {
"user": "some-other-user",
"tweet": "this is some tweet",
"date" : "2012-01-06"
}
});
I have a collection,
window.Tweets = Backbone.Collection.extend(null,{
url: '/tweets/',
model: Tweet,
parse: function(response) {
return response.results;
}
});
and I have a view
window.TweetsView = Backbone.View.extend({
el: $('#content-top'),
initialize: function(){
this.model.bind('change',this.render,this);
},
render: function() {
var TweetsCollection = Backbone.Collection.extend({
model : Tweet,
url: '/tweets/',
parse: function(response) {
return response.results;
}
});
var tweets = new TweetsCollection;
tweets.fetch();
console.log(tweets.toJSON());
} ...
Both
alert(tweets.at(0));
and
alert(tweets.length)
give me "Undefined." What am I missing?
EDIT
If I log the response (in the view), I do get something back:
[object Object],[object Object],[object Object]
so, I'm close, but still missing something.
Based on your comments, I would say the data is coming in right.
Try adding console.log(response); in your parse function.
In my backbone models, the parse() method just returns the first argument, which would be response in your case. I think you need to just change
return response.results;
to
return response;
Related
I have properly coded a simple REST api and several backbone models. My parent model is called Topic and child model called Questions.
I'm trying to call a get method on the REST api and display the received Topic object to the user in a presentable manner. I am receiving the json (can be seen in the network tab on Chrome), but it is not getting sent to the view correctly.
Model:
var Topic = Backbone.Model.extend({
urlRoot: ROOT + '/topic',
idAttribute: 'topicId',
initialize: function () {
this.questions = new Questions([], {parent: this});
},
toJSON: function () {
var json = Backbone.Model.prototype.toJSON.call(this);
json.questions = this.questions.toJSON();
return json;
}
});
var Topics = Backbone.Collection.extend({
model: Topic,
url: ROOT + 'topic',
parse: function (response) {
return response.results;
}
})
REST URL:
http://localhost/Project/index.php/rest/resource/topic/
Backbone View: This is where I think the error is...(console log below prints an empty object)
var TopicListView = Backbone.View.extend({
el: '.page',
render: function () {
var that = this;
var topics = new Topics();
topics.fetch({
success: function (topics) {
console.log(topics);
var template = _.template($('#topic-list-template').html(), {topics: topics.models});
that.$el.html(template);
}
})
}
});
Using the above functions:
var topic = new Topic();
topic.fetch();
topicListView = new TopicListView();
var Router = Backbone.Router.extend({
routes: {
"": "home"
}
});
var router = new Router;
// render topic list for 'home'
router.on('route:home', function () {
topicListView.render();
});
Edit: Solution: Overriding the parse function in the collection proved to be the error. I wonder why...
The argument topics in your success handler is shadowing the variable topics.
The argument contains the parsed JSON response, not the Backbone Collection. You don't need that, so you can remove the argument.
The reference to topics will now be to your Collection, so topics.models will have the value you expect.
topics.fetch({
success: function () { // argument removed here so `topics` is no longer shadowed
var template = _.template($('#topic-list-template').html(), { topics: topics.models });
that.$el.html(template);
}
})
I seem to be fetching correctly from the server using backbone. A GET request is made to a MongDB collection, via the Node.js server code here:
exports.getTeams = function(req,res,next){
var system_db = req.system_db;
var user_id = req.mainUser._id;
var teams = teamModel.getNewTeam(system_db,user_id);
teams.find({}, function (err, items) {
res.json(items);
});
};
I am fetching from Backbone like so:
var teamCollection = new TeamCollection([]);
teamCollection.url = '/api/teams';
teamCollection.fetch(
{success:function(){
console.log('teamCollection length:',teamCollection.length);
console.log('teamCollection[0]:',teamCollection[0]);
}}
);
using this model and collection:
var Team = Backbone.Model.extend({
idAttribute: "_id",
urlRoot: 'http://localhost:3000/api/teams'
});
var TeamCollection = Backbone.Collection.extend({
model: Team,
initialize: function() {
this.bind('add', this.onModelAdded, this);
this.bind('remove', this.onModelRemoved, this);
this.bind("change", this.onModelChanged, this);
},
/* parse: function(data) {
//return JSON.stringify(data).objects;
//return JSON.parse(data).objects;
return data.objects;
},*/
onModelAdded: function(model, collection, options) {
console.log("added, options:", options);
},
onModelRemoved: function (model, collection, options) {
console.log("removed, options:", options);
},
onModelChanged: function (model, collection, options) {
console.log('Collection has changed.');
},
comparator: function (model) {
return model.get("_id");
}
});
the problem is that the logging statements above log the following in the browser console:
It says I am sending 4 items from the server to the Backbone client, but the first one is undefined. How could this be?
A Backbone.Collection is not an array-like object : it has a length attribute representing the number of models but you can't access individual models via indexes, hence
console.log(teamCollection[0]); //undefined
To get a model at a given position, use collection.at .Try
console.log(teamCollection.at(0));
And a demo of those behaviors http://jsfiddle.net/nikoshr/013gjpny/
I am trying to load data from an API into a view. However the data doesn't turn up in my view.
I tried getting the collection information in de router, as well as in the model.
However the date won't even console.log the data. Let alone that I can load the data into the view.
I am using require to load the JavaScript files. Can you have a look and see what I am doing wrong here?
I do see this console.log:
console.log("People Collection is initialized");
And I can also see the page loaded and the json. But not the console.log of the data in the url function... In fact I get this error in the console:
Error: A "url" property or function must be specified
In the Backbone Router:
var OF = OF || {};
OF.AdminRouter = Backbone.Router.extend({
routes: {
"users": "goToUsers",
"users/*other": "goToUsers"
},
goToUsers: function() {
require(['./models/users', './views/users_view', './views/menu_view', './collections/user_collection'], function(UsersMdl, UsersView, MenuView, UsersCollection) {
OF.usersView = new OF.UsersView;
OF.usersView.render();
});
}
});
The Collection:
var OF = OF || {};
OF.UsersCollection = Backbone.Collection.extend({
initialize: function() {
console.log("People Collection is initialized");
},
url: function() {
var that = this;
var sendObj = {
"admin": OF.login.attributes.admin,
"session": OF.login.attributes.session
};
$.ajax({
url: 'php/api/users/',
type: "POST",
dataType: "json",
data: sendObj,
success: function(data) {
console.log(data);
},
error: function(data) {
console.log("ERR: " + data);
}
});
},
model: OF.UsersMdl
});
The Model:
var OF = OF || {};
OF.UsersMdl = Backbone.Model.extend({
default: {
username: '',
homefoldersize: '',
email: ''
},
initialize: function(){
//on change functions can be done here
OF.usersCollection = new OF.UsersCollection();
OF.usersCollection.fetch();
},
result: {
success: false,
message: ''
},
validate: function(att) {
}
});
The View:
var OF = OF || {};
OF.UsersView = Backbone.View.extend({
el: '#content',
remove: function() {
this.$el.empty();
this.stopListening();
return this;
},
initialize: function() {
//set the new address variable.
OF.usersMdl = OF.usersMdl || new OF.UsersMdl();
},
render: function() {
/*
//first check if you are allowed to see this page
if (!OF.login || !OF.login.isValid()) {
OF.router.navigate('login', {trigger: true});
return;
}
*/
//save this in that
var that = this;
//when importing of login page (and fill it with info) is done
$.when(OF.template.get('users-usersField', function(data) {
var htmlSource = $(data).html();
var template = Handlebars.compile(htmlSource);
var compiled = template(OF.usersMdl.attributes);
//now place the page
that.$el.html(compiled);
//then start the menu
})).then(function(){
setTimeout(function(){
OF.menuView = new OF.MenuView;
OF.menuView.render();
}, 100);
});
$('#logout').show();
}
});
Thanks.
It seems to call the initialize of the collection twice and then continues to call the json function.
In your model's initialization you have
OF.usersCollection = new OF.UsersCollection();
OF.usersCollection.fetch();
But when you fetch your collection, it's going to initialize models for every result it gets back ... which will then trigger fresh collection fetches.
You don't need to create collections for your models inside your models, especially if the model is being created by the collection. Whenever you add a model to a collection (including when the collection creates the model after a fetch) the collection will associate itself with the model.
The general order of things should be:
You define a url function on your collection which returns the URL where you can get the (raw JSON) models of that collection.
You instantiate that collection, and then call fetch on the instance
The collection makes an AJAX call (which you can affect by overriding fetch or sync) and gets back the raw JSON for all of the models.
The collection instantiates new models for each result it gets back; those models are automatically added to the collection, and their .collection is automatically set to the collection.
Once OF.usersCollection.fetch().done(function() {... you can have your views start doing things, as your collection should now be all set.
i have rest api based on django rest framework, that include next method of creation object, that takes the data in JSON-format on 'myapp/create_obj/' and if the data is correct object will created, otherwise it returns an error also in JSON-format.
def create_obj(request):
stream = StringIO(request.raw_post_data)
data = JSONParser().parse(stream)
serializer = ObjSerializer(data=data, many=True)
if serializer.is_valid():
serializer.save()
return JSONResponse(serializer.data, status=201)
else:
return JSONResponse(serializer.errors, status=400)
Also i tried to create a module on backbone.js, that post the input in form data to this method. Im very new to js, in particular to backbone and i bad understand how backbone works with server api. i have something like
App.module('Createobj', function(Mod, App, Backbone, Marionette, $, _) {
Mod.id = 'create-obj';
Mod.controllers = {};
Mod.Obj = Backbone.Model.extend({
defaults: {
real_ref : '',
share : ''
}
});
Mod.View = Marionette.ItemView.extend({
id: 'create-obj-page',
template: '#tpl-create-obj-page',
model: Mod.obj,
ui: {
'real_ref': 'input[name=real_ref]',
'share': 'input[name=share]',
'error': 'div.error'
},
hammerEvents: {
'tap button': 'submit:tap'
},
hammerOptions: {
tap: true
},
showError: function(message) {
this.ui.error
.text(message)
.show();
},
hideError: function() {
this.ui.error.hide();
},
});
Mod.Controller = SRClient.PageController.extend({
id: Mod.id + '.main',
ViewClass: Mod.View,
setup: function() {
this.listenTo(this.view, 'submit:tap', this.submit);
},
submit: function() {
var real_ref = this.view.ui.real_ref.val(),
share = this.view.ui.share.val();
if (!real_ref || !share) {
this.view.showError($t('create-obj.error_empty_fields'));
return;
}
App.vent.trigger('loading-screen:show', $t('app.please_wait'));
var obj = new Mod.obj({
real_ref : this.view.ui.real_ref.val(),
share : this.view.ui.share.val()
});
}});
Mod.addInitializer(function() {
Mod.Controllers = {
default: Mod.Controller
};
App.pageControllers[Mod.id] = Mod;
});
});
What i need to do, that data which i input in webform sends to 'myapp/create_obj' in json-format? Thanks!
Backbone expects a RESTful api so instead of being the endpoint an action like create_obj, REST works with Resources and with HTTP methods. In your case you could have a Model like this:
var Obj = Backbone.Model.extend({
defaults: {
real_ref : '',
share : ''
}
});
and a collection like this
var Objects = Backbone.Collection.extend({
url: 'myapp/obj',
model: Obj
});
the collection has a propetry url that specifies the server endpoint. So the operations will be
POST /myapp/obj/ for create a new item
GET /myapp/obj/:id/ if you want to retreive an specific item
GET /myapp/obj/ retreving the whole list
PUT /myapp/obj/:id/ update an item
DELETE /myapp/obj/:id/ delete an item
Tastypie is a good framework to create RESTful api with Django.
i'm using backbone method save to update user object on parse.com. object that in backbone are based on a model and collection. When i fetch it's all right but when save appear: PUT https://api.parse.com/1/classes/_User/xj3QLLYy07 400 (Bad Request)
{"code":206,"error":"Parse::UserCannotBeAlteredWithoutSessionError"}
Model:
var Person = Backbone.Model.extend({
urlRoot: "https://api.parse.com/1/classes/_User/",
idAttribute: "objectId",
defaults:{
},
initialize: function() {
console.log("inperson");
// this.upload();
}
});
return Person;
Collection:
var Usercollection = Backbone.Collection.extend({
model: Person,
url:'https://api.parse.com/1/classes/_User/',
parse: function(data) {
return data.results;
}
});
return Usercollection;
and the code where i try to save the model:
this.model.save({email:"ciao#lib.it"}, {
// wait:true,
success:function(model, response) {
console.log('Successfully saved!');
},
error: function(model, error) {
console.log(model.toJSON());
console.log(error.responseText);
}
});
I think this answer needs an update. Cant you just swap the backbone collection and model to Parse's ones?
Here is a short example that worked for me today