Alex Rivera | Logout

BackboneJS Rendering Problems

Asked 2012-08-17T11:01:37.913
33

For the last six months I've been working with Backbone. The first two months were messing around, learning and figuring out how I want to structure my code around it. The next 4 months were pounding away a production-fit application. Don't get me wrong, Backbone has saved me from the thousands-lines mess of client side code that were the standard before, but it enabled me to do more grandiose things in less time, opening up a complete new stack of problems. For all the questions I raise here there are simple solutions that feels like hacks or just feel wrong. I promise a 300 points bounty for an awesome solution. Here goes:

  1. Loading - For our use case (an admin panel) pessimistic syncing is bad. For some things I need to validate things on the server before accepting them. We started out before the 'sync' event was merged into Backbone,

and we used this little code for mimicking the loading event:

window.old_sync = Backbone.sync

# Add a loading event to backbone.sync
Backbone.sync = (method, model, options) ->
  old_sync(method, model, options)
  model.trigger("loading")

Great. It works as expected but it doesn't feel correct. We bind this event to all the relevant views and display a loading icon until we receive a success or error event from that model. Is there a better, saner, way to do this?

Now for the hard ones:

  1. Too many things render themselves too much - Let's say our application have tabs. Every tab controls a collection. On the left side you get the collection. You click a model to start editing it at the center. You change its name and press tab to get to the next form item. Now, your app is a "real time something something" that notices the difference, runs validations, and automatically sync the change to the server, no save button required! Great, but the H2 at the start of the form is the same name as in the
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1 Answer

9

Ok, in order.. :)

  1. Loading...

In case you want to validate data which stored on server, good practice do it on server-side. If validation on server will be unsuccessful, server should send not 200 HTTP code, therefore save metod of Backbone.Model will trigger error.

Other side, for validation data backbone has unimplemented validate method. I guess that right choise to implement and use it. But keep in mind that validate is called before set and save, and if validate returns an error, set and save will not continue, and the model attributes will not be modified. Failed validations trigger an "error" event.

Another way, when we call silent set(with {silent: true} param), we should call isValid method manually to validate data.

  1. Too many things render themselves too much..

You have to separate your Views under their logic. Good practice for collection is separate view for each model. In this case you could render each element independently. And even more - when you initalizing your container view for collection, you could bind any event from each model in the collection to appropriate view, and they will render automatically.

Great, but the H2 at the start of the form is the same name as in the input - you need to update it. Oh, and you need to update the name on the list to the side.

you could use JQuery on method to implement callback which send value to display. Example:

//Container view
init: function() {
    this.collection = new Backbone.Collection({
        url: 'http://mybestpage.com/collection'
    });
    this.collection.bind('change', this.render, this
answered 2012-08-21T19:19:01.047

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