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
header_register_callback
(PHP 5 >= 5.4.0, PHP 7)
header_register_callback — Call a header function
Descrierea
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.
Parametri
-
callback -
Function called just before the headers are sent. It gets no parameters and the return value is ignored.
Valorile întoarse
Întoarce valoarea true în cazul
succesului sau false în cazul eșecului.
Exemple
Example #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";
?>
Exemplul de mai sus va afișa ceva similar cu:
Content-Type: text/plain a
Note
header_register_callback() is executed just as the headers are about to be sent out, so any output from this function can break output.
Notă:
Antetele vor fi accesibile și afișate doar atunci când este utilizat un SAPI care le susține.
A se vedea și
- headers_list() - Returns a list of response headers sent (or ready to send)
- header_remove() - Remove previously set headers
- header() - Send a raw HTTP header
add a note
User Contributed Notes 1 note
matt@kafene ¶
11 years ago
