The HTTP::Response class encapsulates HTTP style responses. A
response consists of a response line, some headers, and a content
body. Note that the LWP library uses HTTP style responses even 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 following additional methods are available:
Constructs a new HTTP::Response object describing a response with
response code $code and optional message $msg. The optional $header
argument should be a reference to an HTTP::Headers object or a
plain array reference of key/value pairs. The optional $content
argument should be a string of bytes. The meaning these arguments are
described below.
This is used to get/set the code attribute. The code is a 3 digit
number that encode the overall outcome of a HTTP response. The
HTTP::Status module provide constants that provide mnemonic names
for the code attribute.
This is used to get/set header values and it is inherited from
HTTP::Headers via HTTP::Message. See the HTTP::Headers manpage for
details and other similar methods that can be used to access the
headers.
This is used to get/set the content and it is inherited from the
HTTP::Messagebase class. See the HTTP::Message manpage for details and
other methods that can be used to access the content.
This is used to get/set the request attribute. The request attribute
is a reference to the the request that caused this response. It does
not have to be the same request passed to the $ua->request() method,
because there might have been redirects and authorization retries in
between.
This is used to get/set the previous attribute. The previous
attribute is used to link together chains of responses. You get
chains of responses if the first response is redirect or unauthorized.
The value is undefif this is the first response in a chain.
Returns the string ``<code> <message>''. If the message attribute
is not set then the official name of <code> (see the HTTP::Status manpage)
is substituted.
Returns the baseURI for this response. The return value will be a
reference to a URI object.
The baseURI is obtained from one the following sources (in priority
order):
Embedded in the document content, for instance <BASE HREF=``...''>
in HTML documents.
A ``Content-Base:'' or a ``Content-Location:'' header in the response.
For backwards compatibility with older HTTP implementations we will
also look for the ``Base:'' header.
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 baseURI 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).
These methods indicate if the response was informational, successful, a
redirection, or an error. See the HTTP::Status manpage for the meaning of these.
Calculates the ``current age'' of the response as specified by RFC 2616
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.
Calculates the ``freshness lifetime'' of the response as specified by
RFC 2616 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.
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.