gistfile1.js

var signedView = {
 updateSig: function() {
   newSig = this.signature();
   if (newSig !== this._signature) {
     this._signature = newSig;
     return true;
   }
   return false;
 } 
}
var myView = Backbone.View.extend(_.extend({
  template: _.template(whatever),
  render: function() {
    if (this.updateSignature()) {
      this.$el.html(this.template(this.model.toJSON()));
    }
    return this;
  },
  signature: function() {
    return [
      this.model.get('attr1'),
      this.model.get('attr2')
    ].join(';');
  }
}, signedView));