Why ths php dynamic object class creation is not working? - namespaces

Question

I am trying to create a class (working as factory class) in my Zend Expressive APP as follows:
declare(strict_types=1);
namespace App\Install\Factory;
use App\Install\Model as Models;
use App\Install\Abstracts\AttributeInterface;
class AttributeEntityFactory{
public static function create($type1 ='Attribute') : AttributeInterface
{
$resolvedClass = "Models\\$type1";
$resolvedClass1 = 'Models\\'.$type1;
//return new $resolvedClass();
//return new $resolvedClass1();
return new Models\Attribute();
}
}
The above code works perfectly for me. However, if try to use any of the other two return statements it shows
Class 'Models\Attribute' not found
How can I achieve dynamic instantiation?
The attribute class code is as follows:
namespace App\Install\Model;
use App\Install\Abstracts\AttributeInterface;
class Attribute implements AttributeInterface
{
protected $attribute;
public function setAttribute($attribute)
{
$this->attribute = $attribute;
}
public function getAttribute()
{
return $this->attribute;
}
}
My PHP version is:
PHP 7.2.13 (cli) (built: Dec 14 2018 04:20:16) ( NTS )

Answer 1

you may need to pass in the full namespace?
"App\Install\Model\" . $type1;
and more...
the model Attribute you have is in the namespace App\Install\Model, and the object you are trying to create is from Models\\ . $type1
maybe you need to change Models to Model

Answer 2

Personally, I would avoid such factory implementation because of several reasons:
It involves magic.
Less predictable code.
Harder to read for both humans and IDE's (E.g: PHPStorm would not find the usages of Attribute class in such code when you need to find it)
Harder to analyze using static analyzers
Instead, I would rewrite this to a more explicit factory, even if I had dozens of different classes in App\Install\Model namespace:
<?php declare(strict_types=1);
namespace App\Install\Factory;
use App\Install\Model as Models;
class AttributeEntityFactory
{
public static function create($type = 'Attribute') : AttributeInterface
{
switch ($type) {
case 'Attribute':
return new Models\Attribute();
case 'SomethingElse':
return new Models\SomethingElse();
default:
throw new \InvalidArgumentException(
sprintf('An unknown type %s requested from %s', $type, __METHOD__)
);
}
}
}
As a rule of thumb:
Never compose classnames / namespaces using strings concatenated with variables / parameters / constants whatever.
Never call methods in such way, too.
You'll thank me when your application/business/codebase grows enough.