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ob_list_handlers

(PHP 4 >= 4.3.0, PHP 5, PHP 7, PHP 8)

ob_list_handlersList all output handlers in use

Descrição

ob_list_handlers(): array

Lists all output handlers in use.

Parâmetros

Esta função não possui parâmetros.

Valor Retornado

This will return an array with the output handlers in use (if any).

If output_buffering is enabled and no output_handler is set, or no callback or null was passed to ob_start(), "default output handler" is returned. Enabling output_buffering and setting an output_handler is equivalent to passing an internal (built-in) function to ob_start().

If a callable was passed to ob_start(), the fully qualified name of the callable is returned. If the callable is an object implementing __invoke(), the fully qualified name of the object's __invoke() method is returned. If the callable is a Closure, "Closure::__invoke" is returned.

Exemplos

Exemplo #1 ob_list_handlers() example

<?php
// using output_buffering=On, no output_handler set
var_dump(ob_list_handlers());
ob_end_flush();

// no callback or null
ob_start();
var_dump(ob_list_handlers());
ob_end_flush();

// anonymous function
ob_start(function($string) { return $string; });
var_dump(ob_list_handlers());
ob_end_flush();

// arrow function
ob_start(fn($string) => $string);
var_dump(ob_list_handlers());
ob_end_flush();

// first class callable
$firstClassCallable = userDefinedFunction(...);

ob_start([$firstClassCallable, '__invoke']);
var_dump(ob_list_handlers());
ob_end_flush();

// internal (built-in) function
ob_start('print_r');
var_dump(ob_list_handlers());
ob_end_flush();

// user-defined function
function userDefinedFunction($string, $flags) { return $string; };

ob_start('userDefinedFunction');
var_dump(ob_list_handlers());
ob_end_flush();

class
MyClass {
public static function
staticHandle($string) {
return
$string;
}

public static function
handle($string) {
return
$string;
}

public function
__invoke($string) {
return
$string;
}
}

// class and static method
ob_start(['MyClass','staticHandle']);
var_dump(ob_list_handlers());
ob_end_flush();

// object and non-static method
ob_start([new MyClass,'handle']);
var_dump(ob_list_handlers());
ob_end_flush();

// invokable object
ob_start(new MyClass);
var_dump(ob_list_handlers());
ob_end_flush();
?>

O exemplo acima produzirá:

array(1) {
  [0]=>
  string(22) "default output handler"
}
array(1) {
  [0]=>
  string(22) "default output handler"
}
array(1) {
  [0]=>
  string(7) "print_r"
}
array(1) {
  [0]=>
  string(19) "userDefinedFunction"
}
array(1) {
  [0]=>
  string(17) "Closure::__invoke"
}
array(1) {
  [0]=>
  string(17) "Closure::__invoke"
}
array(1) {
  [0]=>
  string(17) "Closure::__invoke"
}
array(1) {
  [0]=>
  string(21) "MyClass::staticHandle"
}
array(1) {
  [0]=>
  string(15) "MyClass::handle"
}
array(1) {
  [0]=>
  string(17) "MyClass::__invoke"
}

Veja Também

  • ob_end_clean() - Clean (erase) the contents of the active output buffer and turn it off
  • ob_end_flush() - Flush (send) the return value of the active output handler and turn the active output buffer off
  • ob_get_flush() - Flush (send) the return value of the active output handler, return the contents of the active output buffer and turn it off
  • ob_start() - Ativa o buffer de saída

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