Backbone.sync per model - backbone.js

Is there a way to have a different Backbone.sync method invoked for a subset of models in an application?
I have been experimenting with binding models to socket.io, but I don't want all of them to work that way. I would like some of them to stick with REST.
Am I asking the wrong question and overriding sync is the wrong approach?

var Model = Backbone.Model.extend({
sync: function (method, model, options) {}
})

Related

Backbone JS - Combination of collection, views and models

I had the following setup now in three different projects, so I thought maybe it's worth asking here. There's a chance I'm not the only person wondering about this.
So there it comes:
I have a list of objects
The list items have a special function like draggable or onClick-Events
My question: How do I build this scenario with Backbone?
I guess I create a model and a view for my list objects. I use a collection for keeping together my objects.
Now I wonder: Do I instantiate the object view in the model constructor and instantiate the models in the collection constructor? Or is there a better way to achieve what I want?
Neither; use a mediator to instantiate the views and inject them with their model/collection.
Marionette.js has a nice implementation for this sort of mediating object, called Controller - I suggest you check it out.
Further more, you don't have to explicitly instantiate the collection models - just declare their type in the collection's prototype, e.g.:
var MyModel = Backbone.Model.extend({
// do some shit
});
var MyCollection = Backbone.Collection.extend({
model: MyModel // pass the type for the collection to instantiate
});
Taking our mediator/controller approach further, this is how it could be done (with Marionette.js):
var MyController = Marionette.Controller.extend({
initialize: function () {
this.myCollection = new MyCollection();
this.myCollectionView = new MyCollectionView({
collection: this.myCollection
});
}
});
This, of course, is just a skeleton code, meant to roughly demonstrate the MVC approach, but it's a good starting point.

Backbone.js with non-RESTful servers save method

I'm starting to implement backbone.js on a new app, however, the API I'm using it is not kind of restful, so I want to know if I can still use some similar methods, for sample:
Let's say I have a trivial scenario where I need among other options to delete users, however each option has its own controller, so I trigger them like this:
fetch : FetchController.php
Update : DeleteController.php?data={'id':'x'}
So my view would look like this:
var UserEditView = Backbone.View.extend({
events: {
'submit .delete-form': 'deleteUser'
},
//.... other methods
deleteUser: function(event) {
//user is a instance of my User Collection
this.user.destroy({
//here is where I point my question
});
}
});
Let's say all my controllers are called via Post Method, so I don't have the change to send a Delete Method to destroy... my question is, can I create a own destroy method? or at least configure it to call an custom controller? so I can do the same to create and edit records?
Any help would be really appreciated.
Thanks in advance.
You should definitely use $.ajax options override it with attributes url, method and data
model.fetch({
url: 'FetchController.php'
});
model.destroy({
url: 'DeleteController.php',
method: 'POST',
data: "id=x"
});
You may also override fetch and destroy method inside your model to do not use this every time in views.
Or even override Backbone.sync method to support your backend services. Here is a link to related question.

Using Backbone models with AngularJS

Recently I was thinking about the differences and similarities between Backbone.js and AngularJS.
What I find really convenient in Backbone are the Backbone-Models and the Backbone-Collections. You just have to set the urlRoot and then the communication with the backend-server via Ajax basically works.
Shouldn't it be possible to use just the Backbone-Models and Collections in AngularJS application?
So we would have the best of both worlds two-way data-binding with AngularJS and convenient access to the server-side (or other storage options) through Backbone-Models and Collections.
A quick internet search didn't turn up any site suggesting this usage scenario.
All resources either talk about using either the one or the other framework.
Does someone have experience with using Backbone-Models or Collections with AngularJS.
Wouldn't they complement each other nicely? Am I something missing?
a working binding for example above...
http://jsbin.com/ivumuz/2/edit
it demonstrates a way for working around Backbone Models with AngularJS.
but setters/getters connection would be better.
Had a similar idea in mind and came up with this idea:
Add just a getter and setter for ever model attribute.
Backbone.ngModel = Backbone.Model.extend({
initialize: function (opt) {
_.each(opt, function (value, key) {
Object.defineProperty(this, key, {
get: function () {
return this.get(key)
},
set: function (value) {
this.set(key, value);
},
enumerable: true,
configurable: true
});
}, this);
}
});
See the fiddle: http://jsfiddle.net/HszLj/
I was wondering if anyone had done this too. In my most recent / first angular app, I found Angular to be pretty lacking in models and collections (unless I am missing something of course!). Sure you can pull data from the server using $http or $resource, but what if you want to add custom methods/properties to your models or collections. For example, say you have a collections of cars, and you want to calculate the total cost. Something like this:
With a Backbone Collection, this would be pretty easy to implement:
carCollection.getTotalCost()
But in Angular, you'd probably have to wrap your custom method in a service and pass your collection to it, like this:
carCollectionService.getTotalCost(carCollection)
I like the Backbone approach because it reads cleaner in my opinion. Getting the 2 way data binding is tricky though. Check out this JSBin example.
http://jsbin.com/ovowav/1/edit
When you edit the numbers, collection.totalCost wont update because the car.cost properties are not getting set via model.set().
Instead, I basically used my own constructors/"classes" for models and collections, copied a subset of Backbone's API from Backbone.Model and Backbone.Collection, and modified my custom constructors/classes so that it would work with Angular's data binding.
Try taking a look at restangular.
I have not implemented it anywhere, but I saw a talk on it a few days ago. It seems to solve the same problem in an angular way.
Video: http://www.youtube.com/watch?v=eGrpnt2VQ3s
Valid question for sure.
Lot of limitations with the current implementation of $resource, which among others doesn't have internal collection management like Backbone.Collection. Having written my own collection/resource management layer in angular (using $http, not $resource), I'm now seeing if I can substitute much of the boilerplate internals for backbone collections and models.
So far the fetching and adding part is flawless and saves code, but the binding those backbone models (or the attributes within, rather) to ng-models on inputs for editing is not yet working.
#ericclemmons (github) has done the same thing and got the two to marry well - I'll ask him, get my test working, and post the conclusion...
I was wondering the same-
This is the use-case:
salesforce mobile sdk (hybrid) has a feature called smartstore/smartsync, that expects backbone models/collection ,which gets saved to local storage for offline access .
And you guessed it right, we want to use angularjs for rest of the hybrid app.
Valid question.
-Sree
You should look at the angularJS boilerplate with parse here. Parse is backbone like, but not exactly backbone. Thats where im starting my idea of a angularJS backboneJS project

When to use URL attribute for both Collection and Model?

I've been following some Backbone.js tutorials and am a bit confused about when to use 'url' inside Model when there is also a Collection which contains the model. For example I see a lot of code that looks like this, in order to synchronize with the server:
var PostModel = Backbone.Model.extend({});
var PostsModel = Bacbone.Collection.extend({
model: PostModel,
url: "/posts"
});
However I also see some where the model also has 'url' property, like so:
var PostModel = Backbone.Model.extend({
url: "/posts"
});
var PostsModel = Bacbone.Collection.extend({
model: PostModel,
url: "/posts"
});
I think I understand the first method, where I interact with the models only through the collections to which they belong, but I am not sure when you would want to have urls for both a model and its collection.
Sometimes you need a model that doesn't belong to any collection.
For example a login/sign in.
var LoginModel = Backbone.Model.extend({
url: "/login"
});
This way you can interact with login view and model just like you would with any other Backbone model, including save() (which posts the login form to the server) and validation.
There is however no login collection, so it doesn't make sense to model that.
Maybe the code you're seeing is something in between. Models are accessed via collection in some places of the application and without collection in others.
If it's a good design is another story, but there's no technical reason to not do it.
edit
As you noticed, using urlRoot is another option, since by default the url attribute is a method that uses urlRoot to construct the relative url.
It can be, however, given a string value to specify the model url directly.

Using multiple plugins in Backbone.js

The plugin model in Backbone.js is really nice, but one thing I'm wondering about is whether it's possible to use multiple plugins without modifying any of the plugin source.
For example, say I've written two plugins for the Collections:
MyBetterCollection = Backbone.Collection.extend({
coolNewFeature: function () {
console.log('This feature is great.');
}
});
MyWayBetterCollection = Backbone.Collection.extend({
wayCoolerNewFeature: function () {
console.log('This feature is even better.');
}
});
I can see some potential issues already, if, for example, both plugins override something like the add method. But having to modify third-party plugins would be a bummer:
MyWayBetterCollection = MyBetterCollection.extend({
...
});
Is there a good approach to handling this situation?
There isn't an easy way to do this. Since there is no traditional inheritance in JavaScript, it's difficult to provide this facility.
You'd have to find plug ins designed to work with each other or fork them and make them compatible.
You could also provide your own extend method that would use the interceptor pattern or some type of monkey patching to provide access to overwritten methods from previous prototypes that were overwritten.
The two collection you've defined above are totally separate from each other. They simply inherit the methods from Backbone.Controller, and if you defined methods with the similar name, then you overwrite those.
Think about Backbone as a class inheritance in other programming languages. Basically, you extend Backbone.Collection as you would do with other languages.
As a result, you can call the superclass, like this
var MyCollection = Backbone.Collection({
toJSON: function() {
var toJSON = this.constructor.__super__.toJSON.call(this);
toJSON.extra = 'my extra value';
return toJSON;
});
Even if you extend your own collection, the logic remains.

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