Last 5.3 release ever available: PHP 5.3.29 - 5.3 now EOL

header_register_callback

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header_register_callbackCall a header function

Descrição

bool header_register_callback ( callable $callback )

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.

Parâmetros

callback

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

Valor Retornado

Retorna TRUE em caso de sucesso ou FALSE em caso de falha.

Exemplos

Exemplo #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";
?>

O exemplo acima irá imprimir algo similar à:

Content-Type: text/plain

a

Notas

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

Nota:

Headers só serão acessíveis e retornados quando a SAPI que os suporta estiver em uso.

Veja Também

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User Contributed Notes 1 note

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2
matt@kafene
1 year 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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