CODEWITHSUNDEEP
phpnamespaces
Mecom
Mecom

Reputation: 411

Understanding php namespace and why the fatal error: undefined constant

Trying to understand how namespace in php works and am stuck.

This below is the architecture of the project.

enter image description here

Class: Loader.php (suppose to load controller/model/ library but for now gibberish test codes)

namespace system\core;

class Loader
{
    public function index()
    {
        echo 'loader';
    }

    public function controller($pathtocontroller)
    {
        // Echo path to the controller
        echo $pathtocontroller;

    }
}

index.php

require 'system/core/Loader.php';
require 'system/core/BaseController.php';
require 'app/controller/common/HomeController.php';

use system\core;
use app\controller;

$loader = new \system\core\Loader();
$loader->controller(app\controller\common\HomeController);

and this is the error I get

Fatal error: Undefined constant 'app\controller\common\HomeController' in C:\xampp\htdocs\psrstd\index.php on line 20. Lin 20 on index is $loader->controller(app\controller\common\HomeController);

Expected Result: app/controller/common/HomeController

in case you wondering what's in there at the HomeController (again gibberish test code)

namespace app\controller\common;
use system\core\BaseController;

class HomeController extends BaseController
{
    public function index()
    {
        echo 'home';
    }
}

Upvotes: 3

Views: 5050

Answers (1)

hassan
hassan

Reputation: 8298

you are passing a constant type to your controller method,

you are aiming to pass an object [ dependency injection ] so you will need to instantiate your argument like :

$loader->controller(new \app\controller\common\HomeController);

otherwise you may send this argument as a string like :

$loader->controller("\\app\\controller\\common\\HomeController");

and instantiate that object within your method [ as a factory method ]

public function controller($pathtocontroller)
{
    // new $pathtocontroller and so on

}

Further reading :

What is Dependency Injection?

Factory design pattern

Upvotes: 1

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