HTTP::Response - Class encapsulating HTTP Responses
SYNOPSIS
require HTTP::Response;
DESCRIPTION
The "HTTP::Response" class encapsulates HTTP style responses. A
response consists of a response line, some headers, and (potentially
empty) content. Note that the LWP library also uses HTTP style
responses for non-HTTP protocol schemes.
Instances of this class are usually created and returned by the
"request()" method of an "LWP::UserAgent" object:
"HTTP::Response" is a subclass of "HTTP::Message" and therefore
inherits its methods. The inherited methods most often used are header(),
push_header(), remove_header(), and content().
The header convenience methods are also available. See
HTTP::Message for details.
Constructs a new "HTTP::Response" object describing a response with
response code $rc and optional message $msg. The message is a
short human readable single line string that explains the response
code.
$r->code([$code])
$r->message([$message])
$r->request([$request])
$r->previous([$previousResponse])
These methods provide public access to the object attributes. The
first two contain respectively the response code and the message
of the response.
The request attribute is a reference the request that caused 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->status_line
Returns the string "<code> <message>". If the message attribute
is not set then the official name of <code> (see HTTP::Status)
is substituted.
$r->base
Returns the base URI for this response. The return value will be a
reference to a URI object.
The base URI 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 URI used to request this response. This might not be the original
URI 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 URI embedded in the document (step 1) will already have
initialized the ``Content-Base:'' header. This means that this method
only performs the last 2 steps (the content is not always available
either).
$r->as_string
Returns a textual representation of the response. Mainly
useful for debugging purposes. It takes no arguments.
$r->is_info
$r->is_success
$r->is_redirect
$r->is_error
These methods indicate if the response was informational, sucessful, a
redirection, or an error.
$r->error_as_HTML()
Returns 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
Calculates 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
Calculates 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 no 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.
COPYRIGHT
Copyright 1995-2001 Gisle Aas.
This library is free software; you can redistribute it and/or
modify it under the same terms as Perl itself.