(Perl) REST Follow Redirects

Demonstrates how to follow a 302/303 redirect response.

Chilkat Perl Downloads Perl Module for Windows, MacOS, Linux, Alpine Linux, Solaris

use chilkat();

# This example requires the Chilkat API to have been previously unlocked.
# See Global Unlock Sample for sample code.

$rest = chilkat::CkRest->new();

$bTls = 1;
$port = 443;
$bAutoReconnect = 1;
$success = $rest->Connect("chilkatsoft.com",$port,$bTls,$bAutoReconnect);
if ($success != 1) {
    print $rest->lastErrorText() . "\r\n";
    exit;
}

# Send a POST to a URL that will respond with a 302 redirect..
$rest->AddQueryParam("firstName","John");
$rest->AddQueryParam("lastName","Doe");
$responseText = $rest->fullRequestFormUrlEncoded("POST","/echoPost302.asp");
if ($rest->get_LastMethodSuccess() != 1) {
    print $rest->lastErrorText() . "\r\n";
    exit;
}

$statusCode = $rest->get_ResponseStatusCode();

# Examine the response status code
if ($statusCode < 300) {
    print "Not a redirect." . "\r\n";
    print $responseText . "\r\n";
    exit;
}

if ($statusCode > 399) {
    print "Error response: Status code = " . $statusCode . "\r\n";
    print $responseText . "\r\n";
    exit;
}

print "Redirect status code = " . $statusCode . "\r\n";

# The response header will contain a Location field with the redirect URL, such as this:
# Location: http://www.chilkatsoft.com/echoPostFinal.asp

# The response status code determines how the client should behave.
# Here are some common possibilities:

# 301: Moved Permanently
# This and all future requests should be directed to the given URI.  (Keep the original HTTP method for the redirect.  In this case, the 
# original request was a POST, so we POST to the redirect URL.)

# 302: Found (aka Object Moved aka Moved Temporarily)
# This is the most popular redirect code, but also an example of industrial practice contradicting the standard. HTTP/1.0 specification (RFC 1945 ) required the client
# to perform a temporary redirect (the original describing phrase was Moved Temporarily), but popular browsers implemented it as a 303 See Other. Therefore, HTTP/1.1
# added status codes 303 and 307 to disambiguate between the two behaviors. However, the majority of Web applications and frameworks still use the 302 status code
# as if it were the 303.

# 303: See Other
# The response to the request can be found under another URI using a GET method. When received in response to a PUT, it should be assumed that the server has
# received the data and the redirect should be issued with a separate GET message.

# 307: Temporary Redirect
# In this occasion, the request should be repeated with another URI, but future requests can still use the original URI. In contrast to 303, the request method
# should not be changed when reissuing the original request. For instance, a POST request must be repeated using another POST request.

print $rest->responseHeader() . "\r\n";

# redirectUrl is a Url
$redirectUrl = $rest->RedirectUrl();
if ($rest->get_LastMethodSuccess() == 0) {
    print "No Location header found for redirect." . "\r\n";
    exit;
}

# Prep for the redirect..
$rest->ClearAllParts();

# Disconnect and re-connect.  
# (This can be skipped if both the host and SSL/TLS conditions are the same.)
$rest->Disconnect(100);
$success = $rest->Connect($redirectUrl->host(),$redirectUrl->get_Port(),$redirectUrl->get_Ssl(),$bAutoReconnect);
if ($success != 1) {
    print $rest->lastErrorText() . "\r\n";
    exit;
}

if (($statusCode == 301) or ($statusCode == 307)) {
    # Redirect using a POST, sending the same params to the new destination
    $rest->AddQueryParam("firstName","John");
    $rest->AddQueryParam("lastName","Doe");
    $responseText = $rest->fullRequestFormUrlEncoded("POST",$redirectUrl->path());
    if ($rest->get_LastMethodSuccess() != 1) {
        print $rest->lastErrorText() . "\r\n";
        exit;
    }

}

if (($statusCode == 302) or ($statusCode == 303)) {
    # Redirect using a GET, sending the query params found in the redirect URL.
    $responseText = $rest->fullRequestFormUrlEncoded("GET",$redirectUrl->pathWithQueryParams());
    if ($rest->get_LastMethodSuccess() != 1) {
        print $rest->lastErrorText() . "\r\n";
        exit;
    }

}

# Show the final status code and the response text.
print "Final status code = " . $rest->get_ResponseStatusCode() . "\r\n";

print "Final response text (HTML, XML, JSON, or whatever..)" . "\r\n";
print $responseText . "\r\n";