Callback Functions

Nette\Utils\Callback is a static class containing functions for working with PHP callbacks.

Installation:

composer require nette/utils

All examples assume the following class alias is defined:

use Nette\Utils\Callback;

check ($callable, bool $syntax=false): callable

Checks if $callable is a valid PHP callback. Otherwise, it throws Nette\InvalidArgumentException. If $syntax is set to true, the function only verifies that $callable has a valid callback structure but does not check if the class or method actually exists. Returns the original $callable.

Callback::check('trim'); // no exception
Callback::check(['NonExistentClass', 'method']); // throws Nette\InvalidArgumentException
Callback::check(['NonExistentClass', 'method'], true); // no exception
Callback::check(function () {}); // no exception
Callback::check(null); // throws Nette\InvalidArgumentException

toString (callable $callable): string

Converts a PHP callback to its textual representation. The class or method does not need to exist.

Callback::toString('trim');                // 'trim'
Callback::toString(['MyClass', 'method']); // 'MyClass::method'

toReflection (callable $callable): \ReflectionMethod|\ReflectionFunction

Returns a reflection for the method or function used in the PHP callback. Throws Nette\InvalidArgumentException if the callback is not valid or does not reference an existing method/function.

$ref = Callback::toReflection('trim');
// $ref is ReflectionFunction('trim')

$ref = Callback::toReflection(['MyClass', 'method']);
// $ref is ReflectionMethod('MyClass', 'method')

isStatic (callable $callable): bool

Checks whether the PHP callback is a global function or a static method. Throws Nette\InvalidArgumentException if the callback is not valid or does not reference an existing method/function.

Callback::isStatic('trim');                // true
Callback::isStatic(['MyClass', 'method']); // true
Callback::isStatic([$obj, 'method']);      // false
Callback::isStatic(function () {});        // false

unwrap (\Closure $closure): callable|array

Unwraps a closure created by Closure::fromCallable(). Returns the original callable array or string.

$closure = Closure::fromCallable(['MyClass', 'method']);
Callback::unwrap($closure);     // ['MyClass', 'method']