ob_list_handlers
(PHP 4 >= 4.3.0, PHP 5, PHP 7, PHP 8)
ob_list_handlers — List all output handlers in use
Elenco dei parametri
Questa funzione non contiene parametri.
Valori restituiti
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.
Esempi
Example #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();
?>Il precedente esempio visualizzerà:
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"
}
Vedere anche:
- 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() - Turn on output buffering
add a note
