Response Evaluation --
Evaluating the information from a HTTP response
Introduction
Because HTTP is a protocol based on the Request -
Response scheme, every HTTP request is followed by a HTTP
response. HTTP_Request offers several methods
to evaluate the information from these responses.
Response Codes
A important part of the HTTP response is the response code. The most
well-known response code probably is 404, which
you may have seen in your browser at several occasions. The meaning
of 404 is that the requested ressource could not
be found. A complete list of status codes can be found in RFC 2616.
Example 48-1. Checking the response code
<?php
require_once "HTTP/Request.php";
$urls = array(
"http://www.example.com/",
"http://example.com/thisdoesnotexist.html"
);
$req =& new HTTP_Request("");
foreach ($urls as $url) {
$req->setURL($url);
$req->sendRequest();
$code = $req->getResponseCode();
switch ($code) {
case 404:
echo "Document not found\n";
break;
case 200:
echo "Everything's ok\n";
break;
/* ... */
}
}
?>
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Response Headers
Similar to a HTTP request a HTTP response consists of a header and a
body. HTTP_Request offers a method to access
the header of the response.
Example 48-2. Getting all headers from the response
<?php
require_once "HTTP/Request.php";
$req =& new HTTP_Request("http://example.com/");
$req->sendRequest();
foreach ($req->getResponseHeader() as $name => $value) {
echo $name . " = " . $value . "\n";
}
?>
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This will print all headers and the appendant values.
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Example 48-3. Getting a specific header
<?php
require_once "HTTP/Request.php";
$req =& new HTTP_Request("http://example.com/");
$req->sendRequest();
echo $req->getResponseHeader("Date");
?>
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This will print the value of the Date: header.
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Response Cookies
Fetching the cookies that are part of the HTTP response is described
in the Cookies section.
