MVC: Having static method in models - php

Question

Concise: How I can avoid using static methods in a model?
Loquacious: Suppose I have a user class. Having userID I can get user name by (new user($userID))->getUserName(). Fine, what if I want to lookup a user? (new user())->lookup($uname, $pass). Still fine, but the latter case could be done via a simple static method user::lookup($uname, $pass)!
Some thoughts:
It's OK! Use (new object())->method() whenever you want. So should I create a hollow object to call a function?
Move this function out of your model. If it needs a DB lookup, where is better than Model context?
Define it as a static method. So isn't it lame to have a mixture of public and static methods in a class?
Side note: I've searched this question, no avail!

Answer 1

Move this function out of your model. If it needs a DB lookup, where is better than Model context?
Yes, indeed, this is the best way to solve the problem.
Currently your User class violates single responsibility principle which basically, says "one task - one class".
Right now your User describes user entity/state and handles persistence (in your case - retrieval from database). See, two things.
I suggest you create another class that is going to handle persistence tasks, like add/update/delete user. The simplest solution is to create a primitive repostitory, like this:
<?php
class UserRepository
{
public function addUser(User $user);
public function updateUser(User $user);
public function deleteUser(User $user);
public function getUserById($id);
}
Then retrieval of user can be done in the following manner:
// get an instance of this repository class
$userRepository = new UserRepository;
// ask it to find and return user from the database by ID
$user = $userRepository->getUserById($_GET['id']);
Easy to read, easy to handle, right?
This UserRepository class is actually a primitive implementation of Repository Pattern. UserRepository emulates an in-memory collection of all of your users, hiding implementation inside. It hides actual persistence mechanism from you as user: imagine, your coleague would write this class and you're just using its methods, like UserRepository::getById(1) - you don't even know/care if it grabs data from files/db/API. That's neat. )
This particular implementation is described very clearly in Kristopher Wilson's book "The Clean Architecture in PHP", which I highly recommed for you to read: it will take you two-three evenings, and push you to the next level.
You can extend the list of methods, of course, add lookups, etc.
class UserRepository
{
public function getByCompany(Company $company);
public function getByEmail($email);
public function countTotal();
}
In fact, every time you need to grab/add/update user in the database, you should do it via this repository.
I would like to emphasize that this is a simple implementation of the pattern, particularly, if you compare it to what Martin Fowler describes as Repository. However, in most cases it's totally fine.

Answer 2

It's OK! Use (new object())->method() whenever you want. So should I create a hollow object to call a function?
depends on how much creating an instance will cost
Move this function out of your model
Factory Pattern comes in mind here.
notes here:
What happens when $userID in the first call do not exists?
Isnt your lookup() method not creating 2 instances at one call, first for lookup, second the found one that is returned?
A FactoryPattern for example can have findByID() or findByName() and return an UserObject. And all that should not depend on this syntax at all: (new object())->method(), that is nice, but not always best practise.