return objects as a class property from function php

Question

I am making an MVC application. I made this function in my loader class:

public function load_models($model)
{
    if ($model) {
        set_include_path($this->modelDirectoryPath);
        spl_autoload_extensions('.php');
        spl_autoload($model);   
    }
}    

I'm using this function from my controller like this:

$this->load->load_models('news');

I want to access this model class like this:

$this->load->news->get_article();

But I can't unless I do this:

$this->load->news = new news();
$this->load->news->get_article();

I want to access it without typing $this->load->news = new news();. I also want it to be automatically instantiated. Can anyone help?

Answer 1

Make get_article() a static method and access it like this:

$this->load->news::get_article();

You cannot access non-static methods without instantiating at least one instance of the class. Even with reflection, you can't actually call and regular method.

You could implement a magic method in the load class that when you access any property such as

$this->load->news->get_article();

it checks to see if the 'news' property's name is also loaded a classname and if it is but it's not set to an instance of the class, create one and assign it to it.

This is the magic method:

public function __get(){ ... } ; 

Basically, this magic method always gets called every time you access an object's ...every time you access an object's inaccesible properties (ones not declared or created)

Answer 2

You seem to be "channeling" something of CodeIgniter, which is severely outdated (if you want to know details, go to PHP chat room). That would not be the framework to emulate, if you want high quality code.

Oh, and the pattern you are implementing is actually MVP, not MVC .. there is a difference.

• At first you should so is make autoloader, which actually works. Read about spl_autoload_register() .. how it is used, what it actually does. If you need some examples, beside the ones provided in comments, you can look up implementations of PSR-0. It should give you some idea, how to use it in practice.

  This all would basically get rid of your $this->load->load_models('news'); line in controller.

• in MVC the Model is a layer not an object/class. I don't intend to repeat whole song and dance, i wrote an answer on this some time ago .. it's long =/

• you should not use new inside the controller, but not for same reason that you think. You should avoid new, because it causes tight coupling to the name of class. Instead you should provide your Controller instance with a Factory in constructor.

  $factory = new DomainFactory( new PDO(...), $cache );
  $controller = new Foobar( $factory );
  
  $controller->$command($request);
  

  This you could use in the controllers method like this:

  public function __construct( $domain_factory )
  {
      $this->factory = $domain_factory
  }
  
  public function do_stuff( $request )
  {
      $id = $request->getQuery('id');
      $articles = $this->factory->build('news')->get_article($id);
      // thought i would split this line into two parts
  }
  

  Oh .. and what factory would do, would be this:

  public function __construct( $pdo, $cache )
  {
      $this->pdo = $pdo;
      $this->cache = $cache;
  }
  
  public function build( $name )
  {
      $instance = new $name;
      $instance->assign_connection( $this->pdo );
      $instance->assign_cache( $this->cache );
      return $instance;
  }
  

This should give you some ideas ..

Here are few links which you might find helpful, if you want to learn how to do good object oriented code, which follows best practices:

• GUI Architectures <= start with this
• Inheritance, Polymorphism, & Testing
• Advanced OO Patterns ^(slides)
• Unit Testing
• The Principles of Agile Design
• Global State and Singletons
• Don't Look For Things!
• Beyond Frameworks ^(slide)
• Agility and Quality ^(slides)