Inline interface implementation - Implement interface methods at declaration - php

Question

I come from java, where we can do something like this:
Action.java:
public interface Action {
public void performAction();
}
MainClass.java:
public class MainClass {
public static void main(String[] args) { //program entry point
Action action = new Action() {
public void performAction() {
// custom implementation of the performAction method
}
};
action.performAction(); //will execute the implemented method
}
}
As you can see, I'm not creating a class which implements Action, but I'm implementing the interface directly on declaration.
Is something like this even possible with PHP?
What I've tried:
action.php:
<?php
interface Action {
public function performAction();
}
?>
myactions.php:
include "action.php";
$action = new Action() {
public function performAction() {
//do some stuff
}
};
What I get:
Parse error: syntax error, unexpected '{' in myactions.php on line 3
So, my question is: is something like this possible with PHP? How should I do it?

Answer 1

With PHP 7, this has become possible with anonymous classes.
$action = new class implements Action() {
public function performAction() {
//do some stuff
}
};

Answer 2

No, can't. PHP doesn't offer anonymous classes like Java does. You can however try to simulate the behaviour you want, but the results will be...mixed at best.
Here's some code:
interface Action
{
public function performAction();
}
class MyClass
{
public function methodOne($object)
{
$object->performAction(); // can't call directly - fatal error
// work around
$closure = $object->performAction;
$closure();
}
public function methodTwo(Action $object)
{
$object->performAction();
}
}
$action = new stdClass();
$action->performAction = function() {
echo 'Hello';
};
$test = new MyClass();
$test->methodOne($action); // will work
$test->methodTwo($action); // fatal error - parameter fails type hinting
var_dump(method_exists($action, 'performAction')); // false
var_dump(is_callable(array($action, 'performAction'))); // false
Hope it helps!