在PHP中自动加载为“模拟”类

Question

Lets suppose I want to auto load classes, so far thats normal. Now, lets suppose we are in "test" environment. I want to load other classes instead, this classes act just like others, but with some modifications. So, originally

class A
{
    public function method()
    {
        return rand(1,10);
    }

$a = new A(); // in the meantime autoloader finds and load class A
$a->method();

and what I want:

class Adev
{
    public function method()
    {
        something::log ('method running');
        return rand(1,10);
    }
}

$a = new A(); // and then I dont need "A" class but "Adev"
$a->method();

so somewhat "renaming" method should be used, instead of refactoring the code.

Answer 1

use get_declared_classes and eval eg

$classes = get_declared_classes();
foreach ($classes as $class)
    eval("\$".$class." = new ".$class."();");

Answer 2

Updated (and messy)
A couple of possible ways of tackling your issue - may be worth a closer look. At the bottom, there is also a personal consideration/suggestion.

The shortest of short fixes might just apply in your case: instead of having PHP's autoloader looking for the .php extension, you could set it so that, when testing your code, you are in fact looking for files ending on dev.php , so that class A , when passed as a string to the autoloarder becomes Adev.php :

if (RUNNING_ENV=== 'test')
{
    spl_autoload_extensions('dev.php');
}

Not sure, but perhaps use getenv() to determine if you're running on test/dev or production environment, and based on that register different autoloaders? spl_autoload_register is a handy function for that:

function prodAutoload($class)
{
    //normal loading
}
function tstAutoload($class)
{
    $class .='Dev';
    //add Dev to className, proceed as you normally would?
}
if (getenv('RUN_ENV') === 'prod')
{
    spl_autoload_register('prodAutoload');
}
else
{
    spl_autoload_register('tstAutoload');
}

Of course, there will be a bit more to it, than just these few lines. But with this approach, you don't need differently named classes: A will be loaded form either the dev or live file, based on the autoloader/extension.
That way, you can at least keep type-hinting all the way through, without any issues. Of course, maintainability will be even more of a nightmare: Edit 1 file, make sure to edit the other one, too.

That's why I must say, personally, I wouldn't go through all this trouble of writing different classes for test & live environments. At one point, you'll run into trouble with that...
Suppose you fix a bug in test, but fail to edit the production version? Or the other way 'round... I think you're better off spending a little time in setting up a decent debugger and test environment that will work with the same code, but (for example) not the actual production databases.

Useful links:

• manage autoload extensions
• workings of default autoloader + examples
• register (multiple) custom autoloaders)

Answer 3

Have you considered using namespaces? The code that follows is probably not 100% correct, but the gist of it would be:

# A.php

class A {...}

# ADev.php

class ADev {...}

# script.php

use ADev as A;

$a = new A; # of class ADev

See:

http://php.net/manual/en/language.namespaces.importing.php

Answer 4

Have you considered a simple solution rather than a complex one?

Make Class A do what ADev does ie include the logging function and forget about duplicating all your classes.

Make the something:: class test a enviroment variable or a simple config variable. So something::debug tests $DO_I_WANT_DEBUGGING_ON = TRUE, if it is then you do the logging otherwise you do not.