PHP static method call with variable class name and namespaces

I’m trying to call a static method for a namespaced class from another class with the same namespace. But the other class’ name is contained in a variable :

<?php 

namespace MyAppApi;
use Eloquent;

class Product extends Eloquent {

    public static function find($id)
    {
        //....
    }

    public static function details($id)
    {
        $product = self::find($id);
        if($product)
        {
            $type = $product->type; // 'Book'
            $product = $type::find($product->id);
            return $product;
        }
    }
}

Here is the Book class :

<?php

namespace MyAppApi;
use Eloquent;

class Book extends Eloquent {

    public static function find($id)
    {
        //....
    }

}

My type variable contains a valid class name here Book. This class is in the same folder, and uses the same namespace. This code returns the error Class 'Book' not found. I have tried several variations (from the SO questions I found) using backslashes, or the call_user_func function, but nothing worked. Anyone knows what’s wrong ?

Answer

When using a variable to reference your class, you need to use a fully qualified name. Try this…

$type = __NAMESPACE__ . '\' . $product->type;
$product = $type::find($product->id);