I am developing a "fat model" for my open-source project, and I am working on the layer that will sit between the ORM (RedBeanPHP) and the controller.
I will have a User class, and probably a UserFactory/UserMapper class that can construct User objects, as well as perform meta-actions like usernameExists, etc.
A number of other SO questions/blog posts have pointed out that if I need to retrieve a collection of User objects, it would be inefficient to have my UserMapper class iterate through through the result set and build n User objects.
My idea then, is to create a UserCollection class which implements PHP's ArrayObject class. UserMapper would be able to create a UserCollection that stores the raw result set internally, as a multidimensional array. I could then implement ArrayObject's iterator functions, [], etc to construct the corresponding User objects on demand.
Is this a smart way to do it? What do I need to consider before taking this approach?
It would appear that this is exactly how Laravel's ORM, Eloquent, does it:
class Collection implements ArrayAccess, Arrayable, Countable, IteratorAggregate, Jsonable, JsonSerializable {
...
public function fetch($key)
{
return new static(array_fetch($this->items, $key));
}
}
If the most popular PHP framework is doing it that way, I'd say it's a pretty good endorsement.
To render big lists of data, it will in fact be slower using an instance per row. That's where the flyweight pattern comes in handy... http://sourcemaking.com/design_patterns/Flyweight/php