How can I make a call to desired function using Closure object? - php

Question

I created a basic class to play with Closure object a bit. I don't understand the behaviour of this application/closures so I wanted to ask a few things. My mind is pretty cloudy at the moment so I don't know why something runs or why not.
<?php
class Route
{
public static $bindings = array();
public static $dispatch = array();
public static function bind($bind)
{
self::$bindings[] = $bind;
}
public static function getAllBindings()
{
return (array) self::$bindings;
}
public static function get($binding, Closure $dispatch)
{
if(in_array($binding, self::$bindings))
{
if(is_callable($dispatch))
{
return call_user_func($dispatch);
}
else
{
die("Dispatch method is not callable.");
}
}
else
{
die("Binding is not found in bindings array.");
}
}
public static function test()
{
echo "Test ran!";
}
}
Basically, we bind bindings (such as /admin, /account, /profile etc.) Then, we try to call a method using closure.
// Let's bind account and admin as available bindings
Route::bind('account');
Route::bind('admin');
// Let's try doing a get call with parameter "account"
Route::get('account', function() {
// This is where I'm stuck. See below examples:
// Route::test();
// return "test";
// return "testa";
// return self::test();
});
If you checked above, here are my questions:
If I provide a non-existent method, is_callable check does not run and I get a php fatal error. Isn't is_callable a valid check for checking inexistent methods? Why does it happen?
If I provide return "Test"; in the closure, is my $closure parameter in get method going to contain "Test" string?
Can I pass a methods from different classes inside the closure? Like:
Route::get('account', function () {
if(User::isLoggedIn() !== true)
return Error::login_error('Unauthorized.');
});
If so, in which scope this call is being made? PHP's scope in closure, or does call_user_func call it inside Route class' scope since it is passed to it via closure? (To clear it a bit more, PHP's scope may do $route->get but Closure scope may use $this->get)
Is there any way to dump Closure object like var_dump/print_r to see it's contents?
A short guidance will get me going. I know PHP but using closures is pretty new to me.
Thanks alot and I appreciate your replies.

Answer 1

You won't need that is_callable() check as the Closure type hint in the method declaration already ensures this. Also you don't need call_user_func(). This will give you the following get() method:
public static function get($binding, Closure $dispatch)
{
if(!in_array($binding, self::$bindings))
{
die("Binding is not found in bindings array.");
}
return $dispatch();
}
Note : Currently the $binding param will just being used in a check, but not as a param to $dispatch(), what would I have expected. I can't see a reason for that. You should rethink this part
I found another hidden question in your post:
// Let's try doing a get call with parameter "account"
Route::get('account', function() {
// This is where I'm stuck. See below examples:
// Route::test();
// return "test";
// return "testa";
// return self::test();
});
It should look like:
// Let's try doing a get call with parameter "account"
Route::get('account', function() {
// Both should work well:
// Route::test();
// .. or
// return self::test();
});