PHP autoloader with namespaces [duplicate] - php

Question

This question already has answers here:
How do I use PHP namespaces with autoload?
(13 answers)
Closed 6 years ago.
I am trying to understand how to define a working autoloader for a trivial application with namespaces.
I created following structure:
public
index.php
src
Models
WordGenerator.php
Obviously, later it will grow. The WordGenerator.php file is following:
<?php
namespace Models;
class WordGenerator {
public $filename;
public function __construct($filename) {
$this->_filename = $filename;
}
}
Now I try to create instance of this object in index.php:
<?php
use \Models;
$wg = new WordGenerator("words.english");
Obviously I get fatal error because I did not define autoloader. However though, according to documentation all I can pass is $classname. How should I define the autoloader function to take namespace declared by use statement then??
[edit]
I was wrong understood a moment ago. So here's my code for index.php:
spl_autoload_register(function ($className) {
$className = ltrim($className, '\\');
$prepend = "..\\src\\";
$fileName = "{$prepend}";
$namespace = '';
if ($lastNsPos = strrpos($className, '\\')) {
$namespace = substr($className, 0, $lastNsPos);
$className = substr($className, $lastNsPos + 1);
$fileName = $prepend.str_replace('\\', DIRECTORY_SEPARATOR, $namespace) . DIRECTORY_SEPARATOR;
}
$fileName .= str_replace('_', DIRECTORY_SEPARATOR, $className) . '.php';
require $fileName;
});
//require '../src/Models/WordGenerator.php';
use Models;
$wg = new WordGenerator("words.english");
echo $wg->getRandomWord();
Now, this does not work and I get:
Warning: The use statement with non-compound name 'Models' has no effect in C:\xampp\htdocs\Hangman\public\index.php on line 22
Warning: require(..\src\WordGenerator.php): failed to open stream: No such file or directory in C:\xampp\htdocs\Hangman\public\index.php on line 16
Fatal error: require(): Failed opening required '..\src\WordGenerator.php' (include_path='.;C:\xampp\php\PEAR') in C:\xampp\htdocs\Hangman\public\index.php on line 16
However when I change new WordGenerator to new \Models\WordGenerator it works. Now, the question is: how can I pass namespaces declared by use statement to autoloader function to make it work properly?

Answer 1

Your use statement is incorrect. You want use Models\WordGenerator;
The use operator doesn't declare anything but an alias. Consider the expanded form:
use Models\WordGenerator as WordGenerator;
Which is equivalent.
You can alias a namespace rather than a class, but it doesn't work in the way you're attempting. For example:
use Models as Foo;
$wg = new Foo\WordGenerator("words.english");
Would work. However:
use Models;
Is equivalent to:
use Models as Models;
Which effectively does nothing.
For more information see Using namespaces: Aliasing/Importing in the PHP manual.

Answer 2

Please look at documentation. Autoloader must be defined by you at beginning of you script. At provided link there is example autoloader and more complex solution