Dynamic class name in PHP - php

Question

I'm trying to create a system that it has a GeneralObj. The GeneralObj allows user to initiate special objects for database's tables with a String of the table name. So far, it works perfect.
class GeneralObj{
function __construct($tableName) {
//...
}
}
However, it is too tired to type new GeneralObj(XXX) every time.
I am wondering is that possible to simplify the process to like new XXX(), which is actually running the same as new GeneralObj(XXX)?
I spot PHP provided __autoload method for dynamic loading files in the setting include_path but it requires a the actually definition file existing. I really don't want to copy and copy the same definition files only changing a little.
For cause, eval is not an option.

Answer 1

Maybe you can just auto-create the files in the autoloader:
function __autoload($class_name) {
// check for classes ending with 'Table'
if (preg_match('/(.*?)Table/', $class_name, $match)) {
$classPath = PATH_TO_TABLES . '/' . $match[1] . '.php';
// auto-create the file
if (!file_exists($classPath)) {
$classContent = "
class $class_name extends GeneralObj {
public __construct() {
parent::__construct('{$match[1]}');
}
}";
file_put_contents($classPath, $classContent);
}
require_once $classPath;
}
}

Answer 2

Use inheritance. Make GeneralObj the superclass of the table specific classes. This way you can dynamically derive class names and instantiate objects. Example:
class someTable extends GeneralObj {
}
$tableName = 'some';
$className = $tableName . 'Table';
$obj = new $className;

Answer 3

No, this is not possible.
The runkit extension allows programmatic manipulation of the PHP runtime environment, but it cannot do this. Even if it could, it would IMHO be a very bad idea, greatly impacting the requirements and complexity of the application in exchange for saving a few keystrokes.
In an unrelated note, your GeneralObj class has functionality that sounds suspiciously like that of a dependency injection container. Perhaps you should consider replacing it with one?

Answer 4

Something like this autoloader:
myAutoloader::Register();
class myAutoloader
{
/**
* Register the Autoloader with SPL
*
*/
public static function Register() {
if (function_exists('__autoload')) {
// Register any existing autoloader function with SPL, so we don't get any clashes
spl_autoload_register('__autoload');
}
// Register ourselves with SPL
return spl_autoload_register(array('myAutoloader', 'Load'));
} // function Register()
/**
* Autoload a class identified by name
*
* #param string $pClassName Name of the object to load
*/
public static function Load($pClassName){
if (class_exists($pClassName,FALSE)) {
// Already loaded
return FALSE;
}
$pClassFilePath = str_replace('_',DIRECTORY_SEPARATOR,$pClassName) . '.php';
if (file_exists($pClassFilePath) === FALSE) {
// Not a class file
return new GeneralObj($pClassName);
}
require($pClassFilePath);
} // function Load()
}
And it's up to GeneralObj to throw an exception if the table class can't be instantiated