The redirect method of TP frame is how to realize jump? A look at the source, completely incomprehensible AH

protected function Redirect ($url, $params =array (), $delay =0, $msg = ") {
$url = U ($url, $params);
Redirect ($url, $delay, $msg);
}



First live a URL, and then recursively pass in the third fourth parameter:


How does its jump come true???

Reply to discussion (solution)

Then you go and look at the definition of the redirect function.

The redirect in the function body is called a function:

See the framework's built-in functions.php file
redirect
Description
void Redirect ($url, $time =0, $msg = ")
URL redirection
Source:

    function Redirect ($url, $time =0, $msg = ") {        //multiline URL address support        $url = str_replace (Array (" \ n "," \ R "),", $url);        if (empty ($msg))            $msg = "The system will automatically jump {$time} seconds to {$url}! ";        if (!headers_sent ()) {            //redirect            if (0 = = = $time) {                header (' Location: ' $url);            } else {                header ("R efresh:{$time};url={$url} ");                Echo ($msg);            }            Exit ();        } else {            $str = "
 
   ";            if ($time! = 0)                $str. = $msg;            Exit ($STR);        }    }

URL redirection function Redirect ($url, $time =0, $msg = ") {    //multiline URL address support    $url = str_replace (" \ n "," \ R "),", $url) ;    if (empty ($msg))        $msg = "The system will automatically jump {$time} seconds to {$url}! ";    if (!headers_sent ()) {//If the header does not emit        //redirect if        (0 = = = $time) {            header (' Location: '. $url);//If no delay time is specified, send a Jump Header        } else {            header ("refresh:{$time};url={$url}");//If the delay time is set, a delay-refreshed header            Echo ($msg) is issued;        Exit ();    } else {//otherwise send meta tag, meaning ditto        $str = "
 
   ";        if ($time! = 0)            $str. = $msg;        Exit ($STR);}    }

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