lib::HTTP::RespUser(Contributed Perl Documelib::HTTP::Response(3)NAMEHTTP::Response - Class encapsulating HTTP Responses
SYNOPSIS
require HTTP::Response;
DESCRIPTION
The HTTP::Response class encapsulate HTTP style responses.
A response consist of a response line, some headers, and a
(potential empty) content. Note that the LWP library will
use HTTP style responses also for non-HTTP protocol
schemes.
Instances of this class are usually created and returned
by the request() method of an LWP::UserAgent object:
...
$response = $ua->request($request)
if ($response->is_success) {
print $response->content;
} else {
print $response->error_as_HTML;
}
METHODSHTTP::Response is a subclass of HTTP::Message and
therefore inherits its methods. The inherited methods are
header(), push_header(), remove_header(),
headers_as_string(), and content(). The header
convenience methods are also available. See the
HTTP::Message manpage for details.
$r = new HTTP::Response ($rc, [$msg, [$header,
[$content]]])
Constructs a new HTTP::Response object describing a
response with response code $rc and optional message $msg.
$r->code([$code])
$r->message([$message])
$r->request([$request])
$r->previous([$previousResponse])
These methods provide public access to the member
variables. The first two containing respectively the
response code and the message of the response.
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The request attribute is a reference the request that gave
this response. It does not have to be the same request as
passed to the $ua->request() method, because there might
have been redirects and authorization retries in between.
The previous attribute is used to link together chains of
responses. You get chains of responses if the first
response is redirect or unauthorized.
$r->base
Returns the base URL for this response. The return value
will be a reference to a URI::URL object.
The base URL is obtained from one the following sources
(in priority order):
1. Embedded in the document content, for instance <BASE
HREF="..."> in HTML documents.
2. A "Content-Base:" or a "Content-Location:" header in
the response.
For backwards compatability with older HTTP
implementations we will also look for the "Base:"
header.
3. The URL used to request this response. This might not
be the original URL that was passed to $ua->request()
method, because we might have received some redirect
responses first.
When the LWP protocol modules produce the HTTP::Response
object, then any base URL embedded in the document (step
1) will already have initialized the "Content-Base:"
header. This means that this method only perform the last
2 steps (the content is not always available either).
$r->as_string()
Method returning a textual representation of the request.
Mainly useful for debugging purposes. It takes no
arguments.
$r->is_info
$r->is_success
$r->is_redirect
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$r->is_error
These methods indicate if the response was informational,
sucessful, a redirection, or an error.
$r->error_as_HTML()
Return a string containing a complete HTML document
indicating what error occurred. This method should only
be called when $r->is_error is TRUE.
$r->current_age
This function will calculate the "current age" of the
response as specified by <draft-ietf-http-v11-spec-07>
section 13.2.3. The age of a response is the time since
it was sent by the origin server. The returned value is a
number representing the age in seconds.
$r->freshness_lifetime
This function will calculate the "freshness lifetime" of
the response as specified by <draft-ietf-http-v11-spec-07>
section 13.2.4. The "freshness lifetime" is the length of
time between the generation of a response and its
expiration time. The returned value is a number
representing the freshness lifetime in seconds.
If the response does not contain an "Expires" or a "Cache-
Control" header, then this function will apply some simple
heuristic based on 'Last-Modified' to determine a suitable
lifetime.
$r->is_fresh
Returns TRUE if the response is fresh, based on the values
of freshness_lifetime() and current_age(). If the
response is not longer fresh, then it has to be refetched
or revalidated by the origin server.
$r->fresh_until
Returns the time when this entiy is no longer fresh.
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