Some wrappers for Roise, to be able to handle "lazy" attributes

gistfile1.js

Factory.prototype.lazy=function(attr, callback) {
    this._lazy.push(attr);
    this.attrs[attr] = function(){return callback};
    return this;
};
//
Factory.define = _.wrap(Factory.define,function(define,name,constructor){
    var factory = (define.bind(Factory))(name,constructor);
    factory.name=name;
    factory._lazy=[];
    Factory.builds[name] = [];
    return factory;
});
Factory.builds={};
//
Factory.build = _.wrap(Factory.build,function(build,name,attrs){
    var result = (build.bind(Factory))(name,attrs);
    Factory.builds[name].push(result);
    return result;
});
//

Factory.done = function(){
    _.each(Factory.builds,function(instances,name){
        var factory = Factory.factories[name];
        _.each(instances,function(instance){
            _.each(factory._lazy,function(attr){
                instance[attr]=(instance[attr].bind(instance))();
            })
        });
    });
};


Factory.define('pizza')
    .sequence('id')
    .lazy('lazy',function(){return 2})
    .sequence('name',function(i){return 'pizza'+i})
    .attr('_updated', function() { return new Date(); })
    .lazy('toppings', function() {
        var toppings = Factory.builds['topping'];
        toppings =  _.first(_.shuffle(toppings),_.random(0,5));
        _.each(toppings,function(topping){
            topping.pizzas.push(this.id);
        }.bind(this));
        return _.pluck(toppings,'id');

    });

Factory.define('topping')
    .sequence('id')
    .attr('pizzas',function(){return []})
    .sequence('name', function(i) { return 'topping' + i; });


var pizzas = _.map(_.range(1,100),function(){
   return Factory.build('pizza')
});
var toppings = _.map(_.range(1,100),function(){
    return Factory.build('topping')
});


Factory.done();
console.log(pizzas,'pizzas');
console.log(toppings,'toppings');