How does Backbone.JS handle models with calculated attributes

Question

I'm using Backbone.JS with Mustache, so to render my tempaltes I call MyModel.toJSON(). This leaves me with only access to attributes. How can I have some attributes that are always calculated?

I looked at the Backbone.JS documentation and it might work to override validate() but this seems like a hack and may lead to infinite loops.

I also tried making an attribute be a function instead of a value, but Mustache doesn't get a value when I try to use it.

Answer 1

This is how I'm currently doing it. I do the calculations when initializing a model, and adding a listener for changes to the model to recalculate automatically.

...
initialize: function() {
  console.log('Lead:initialize');
  _.bindAll(this, 'validate', 'calculate');
  this.bind('change', this.setCalculations, this);
  this.setCalculations();
},
setCalculations: function() {
  this.set({ calculations: this.calculate() }, { silent: true });
},
calculate: function() {
  // do the calculations and return
},
...