Backbone - Using fetched data inside the view - backbone.js

I have fatched the data to Collection variable, but I am not sure what should I do next. How to use this data and to fill the template with it? Here is my code from the render function inside the View.
Collection.url = "../data";
Collection.fetch();
var compiled = _.template(self.data);
self.$el.prepend(compiled(/*MY JSON SHOULD GO HERE*/));
I am a newbie to backbone, so every help is appreaciated.
Here is a Collection definition:
var MainCollection = Backbone.Collection.extend({
model: MainModel,
//localStorage: new Backbone.LocalStorage("kitchen"),
initialize: function (models,options) { }
}), Collection = new MainCollection;
Here is a log of Collection and Collection coverted to JSON:

Assuming Collection is your collection's name (that's pretty confusing I have to say), this is what you're looking for:
self.$el.prepend(compiled(Collection.toJSON()));
Edit:
Don't forget you're fetching the data asynchronously. So when you're evaluating your template, the data hasn't come back yet, and your collection's still empty. Listen to the end of the request ('sync' event I think) or some other events so you know when the collection's populated OR use the success option of the fetch method to specify a callback :)
As for your logs. When you log an object, it will be automatically updated until you check the details. So you logged it while it was empty, but checked it after it was populated (a few ms afterwards).

Related

Restangular how to update item in collection

I am currently fiddeling around with restangular and ui-router.
I do resolve a collection of items in my router which makes it available to the underlying controllers. I have a list of todos and i want to edit a todo. So i load a view where i can edit the item.
I get the model by $scope.todo = todos.get(id) I make a change to it and then i do $scope.todo.save() which updates the model on the server. But now i have the old item still in the collection of todos.
I want my collection to reflect the changes in the single item. I could delete the item from the collection and reinsert it afterwards, but this seems a little bit too complicated. Is there no easy way to update a model within a collection?
Update: Adding some Code
Note: The todos property gets resolved if the state is called.
If i edit a single todo i resolve it by
resolve : {
todo : function($stateParams, todos) {
return todos.get($stateParams.id);
}
}
I do some changes and then i call todo.save(). No changes will happen on the collection this way. I tried to do a todos.patch(todo) but that actually did a request to weird url and i guess it is intended to patch the whole collection (?)
I am sure there is a way to change a model within a collection, but i dont know how
After trying some stuff i ended up with replacing the item inside the collection. I created a little helper to lodash which i want to show here:
var replaceItemById = function(list, element) {
var index = _.indexOf(list, _.find(list, { id : element.id }));
list.splice(index, 1 , element);
return list;
};
_.mixin({'replaceItemById' : replaceItemById});
When i want to update a model inside a collection i do step by step:
Fetch the collection
Get a single item from the collection and edit it
Call save on the item
//The server returns the updated model
todo.save().then(function(editedTodo) {
_.replaceItemById(todos, editedTodo);
$state.go('todos.index');
});
This way i do not need to fetch the collection again (even if in most cases this is what you would do) and it is up to date after updating a single item.

Backbone sync not updating collection

I thought this would update my model with the response from the server (the call works fine and returns the expected values) but my collection and its models are not being updated. What's wrong with this? Its using create because it posts the the collection which is then returned with changes. As I mentioned the changes come back but the console.log shows that the collection has not changed.
test: function(){
Backbone.sync('create', this.importCollection, {
success : _.bind(function(e) {
console.log(this.importCollection);
},this)
});
},
If you look at Backbone.Sync method in the annotated source, you can see that nowhere does it ever manipulate the model/collection directly, it only makes the ajax call using the model/collection instance.
If you want to call the Backbone.Sync method manually, you're gonna have to populate your collection manually after the ajax call is done. If you want to see how Backbone does it, you can take a look at the Backbone.Collection fetch method.

Backbone.js: Natively passing attributes to models when fetched with a collection

Let say you are defining a Backbone.js Model. From the documentation we have ...
new Model([attributes], [options])
This seems great for passing some default attributes to a model. When passed the model automatically inherits those attributes and their respective values. Nothing to do. Awesome!
On they other hand lets say we have a Collection of that model.
new Backbone.Collection([models], [options])
Okay, cool we can pass some initial models and some options. But, I have no initial models and no options I need to pass so let's continue. I am going to fetch the models from the server.
collection.fetch([options])
Well I don't have any options, but I want to pass some attributes to add to each models as it is fetched. I could do this by passing them as options and then adding them to the attributes hash in the initialize for the model, but this seems messy.
Is their a Backbone.js native way to do this?
You can pass the attributes as options to fetch and over-ride the collection's parse method to extend the passed options (attributes) on the response.
The solution would look like the following:
var Collection = Backbone.Collection.extend({
url:'someUrl',
parse:function(resp,options) {
if (options.attributesToAdd) {
for (var i=0;i<resp.length;i++)
_.extend(resp[i],options.attributesToAdd);
}
return resp;
}
});
Then to add attributes when you call fetch on the collection, you can:
var collection = new Collection();
collection.fetch({
attributesToAdd:{foo:'bar',more:'foobar'}
});
You may have to tweak the code a bit to work with your JSON structure, but hopefully this will get you started in the correct direction.

How to update model in collection?

I have the following Backbone.js collection:
var Tags = Backbone.Collection.extend({
url: "/api/v1/tags/"
}),
How do I update one of the models in the collection so that it posts to /api/v1/tags/id and saves the data for that model.
So if I change name of model with id 2 in the collection
It should PUT to
/api/v1/tags/2 with the following data:
name: new name id: 2
I've also recently wanted to update particular model in the collection. The problem was that if I did use just model.save it didn't update the collection. The goal was to change the model in collection, change it on the server, update collection accordingly and not use the sync method. So for example I have my variable collection and I want to change the model with id = 2. So the first thing, I will create an instance model, like this: var model = collection.get(2)Then I will update the attributes on this particular model:model.set({name: 'new name'})Then I will save it to the server:model.save({}, {url:'/api/v1/tags/'+model.get('id')})Then we have to update collection accordingly to the changes:collection.set({model},{remove: false})set method - it's a 'smart' update of the collection with the list of the models you passed in parameters. remove: false parameter - it's a restriction for a collection to remove existing models in collection. More here.
The first thing you can miss is that in your corresponding Tag model you'll need to set "urlRoot" to match the Collection's "url". Otherwise it doesn't know about the collection at all:
var Tag = Backbone.Model.extend({
urlRoot: "/api/v1/tags"
});
var Tags = Backbone.Collection.Extend({
model: Tag,
url: "/api/v1/tags"
});
This is useful if you want to save the tag separately:
var tag = collection.get(2);
tag.set({key: "something"});
tag.save(); // model.save works because you set "urlRoot"
On the collection, "create()" is also "update()" if id is not null. That's not confusing. :) Therefore, this is pretty much equivalent to the previous sample:
collection.create({id: 2; key: "something"});
This will update the existing tag with id=2 and then trigger a PUT.
This is an ancient question; answering because I was searching for the same answer--you've probably long since solved this problem and moved on. :)
You can pass variables to the save method. It accepts all the options which jQuery's ajax method uses (unless you overrided Backbone.Sync)
You could do something like:
model.save( { name:'new name' } );
The id and PUT method will automatically be added by Backbone for you.

Collection fetch from server, not firing change when model has been delete from server

I am fetching a collection from the server, lets say I originally start with 30 models and in the database one of these models has some of attributes changed, when I fetch the collection the change is detected and the changes are rendered. Fine works just fine.
But when the model is delete in the database and the collection which had 30 and now has 29 does not fire destroy on the missing model. The model does not exist anymore but the view is still rendered and it does not correspond to any model, because the model is not part of the collection anymore. Need help with this one. And the view is binded to "change" and also "destroy".
I already tried all kinds of stuff, many variations in code and nothing seems to work.
Thanks
var commentCollection = new CommentList;
commentCollection.fetch({ data: $.param({ user_id:id}), success: function(){
Profile_view = new Profile({collection: commentCollection});
$("div.Profile_container").html(this.Profile_view.el);
} });
function fetch_collection(commentCollection, id){
//commentCollection.reset();
commentCollection.fetch({update: true, data: $.param({ user_id:id})});
console.log(commentCollection)
}
setInterval(function(){fetch_collection(commentCollection, id)},10000);
I got it!!!!!
All I had to do was bind the remove event to the view function that removes the actual view from the DOM
this.model.bind("remove", this.close, this)

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