Question

Would do something like

m.set('background-color', 'green') for m in @model.collection.where(selected: true)

and then maybe render the attribute somehow?

Is something like this possible?

m.$el.css('opacity', 1) for m in @model.collection.where(selected: true)

Answer 1

Ideally you should define a view and bind it to the change event from your model so that whenever a property is updated on the model, your view will update accordingly, e.g.:

var myView = Backbone.View.extend({

  initialize : function() {
    myModel.bind('change', render);
  },

  render: function() {

    $("#myElement").css('opacity', myModel.isSelect ? 1 : 0)

  }

});