How to use an instance of a class assigned to a property of another class in the other class in php

Question

I am making a framework in PHP. I have an import function in library/core.php.

I can use the function like this:

$core->import("someclass");

This is the function:

public function import()
    {
        $import_resources = func_get_args();

        $check_directories = array("library", "template", "view", "action", "errors");

        $instances = array();

        foreach($import_resources as $resource)
        {
            for($i = 0; $i <= count($check_directories) - 1; $i++)
            {
                if(file_exists($this->appRoot() . $check_directories[$i] . "/" . $resource . ".php"))
                {

                    $classes = get_declared_classes();
                    include ($check_directories[$i] . "/" . $resource . ".php");
                    $included_classes = array_diff(get_declared_classes(), $classes);
                    $last_class = end($included_classes);

                    $last_class_lowercase = strtolower($last_class);

                    $this->$last_class_lowercase = new $last_class(); 
                    // create an instance of the included class and attach it to the Core Class

                }

                else
                {

                }   
            }
        }

    }

So in an other class, I can use it like this:

$core->import("view");
$core->view->get();

The whole point of this, was to make the included class available in another class, when it is extended.

class Someclass extends Core
{
    public function somefunc()
    {
        $this->view->get(); // This does not work. 
    }
}

How could I make it work like this? This is a very important part of the framework, because this is how it works. I think it works similar in popular frameworks like CodeIgniter too.

I was trying to use parent::view->get(), but I guess I don't fully understand it.

I hope I can figure this out, because it is holding me down in my work. Thank you in advance.

Answer 1

What you want to do is use "Magic Methods", this particular one (__get() this gets properties not accessible from outside). You will want to use it like this:

<?php
// --- Begin Importer.php --------------------
class Importer{
    protected $classes = array();

    public function __get($method_name){
        if(array_key_exists($method_name, $this->classes)){
            return $this->classes[$method_name];
        }
    }

    public function import($class_name){
        // Do this or use an auto loader
        require_once __DIR__ . "/../classes/$class_name";
        $this->classes[$class_name] = new $class_name();
    }
}
// --- End Importer.php ---------------------


// --- Begin MyClass.php --------------------
class MyClass{
    public function get(){
        return "hello";
    }
}
// --- End MyClass.php ----------------------


// --- Where ever you call Importer ---------
$importer = new Importer();
$importer->import("MyClass");


echo $importer->MyClass->get();