header_register_callback

(PHP 5 >= 5.4.0, PHP 7)

header_register_callbackCall a header function

Opis

header_register_callback ( callable $callback ) : bool

Registers a function that will be called when PHP starts sending output.

The callback is executed just after PHP prepares all headers to be sent, and before any other output is sent, creating a window to manipulate the outgoing headers before being sent.

Parametry

callback

Function called just before the headers are sent. It gets no parameters and the return value is ignored.

Zwracane wartości

Zwraca TRUE w przypadku powodzenia, FALSE w przypadku błędu.

Przykłady

Przykład #1 header_register_callback() example

<?php

header
('Content-Type: text/plain');
header('X-Test: foo');

function 
foo() {
 foreach (
headers_list() as $header) {
   if (
strpos($header'X-Powered-By:') !== false) {
     
header_remove('X-Powered-By');
   }
   
header_remove('X-Test');
 }
}

$result header_register_callback('foo');
echo 
"a";
?>

Powyższy przykład wyświetli coś podobnego do:

Content-Type: text/plain

a

Notatki

header_register_callback() is executed just as the headers are about to be sent out, so any output from this function can break output.

Informacja:

Nagłówki będą dostępne i zwracane tylko jeśli stosowane jest SAPI które je obsługuje.

Zobacz też:

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User Contributed Notes 1 note

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4
matt@kafene
7 years ago
Note that this function only registers a single callback as of php 5.4. The most recent callback set is the one that will be executed, they will not be executed in order like with register_shutdown_function(), just overwritten.

Here is my test:

<?php

$i
= $j = 0;
header_register_callback(function() use(&$i){ $i+=2; });
header_register_callback(function() use(&$i){ $i+=3; });
register_shutdown_function(function() use(&$j){ $j+=2; });
register_shutdown_function(function() use(&$j){ $j+=3; });
register_shutdown_function(function() use(&$j){ var_dump($j); });
while(!
headers_sent()) { echo "<!-- ... flushing ... -->"; }
var_dump(headers_sent(), $i);
exit;

?>

Results:

headers_sent() - true
$i = 3
$j = 5
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