HTTP::Message - HTTP style message (base class)
use base 'HTTP::Message';
An "HTTP::Message" object contains some
headers and a content body. The following methods are available:
- $mess = HTTP::Message->new
- $mess = HTTP::Message->new( $headers )
- $mess = HTTP::Message->new( $headers, $content )
- This constructs a new message object. Normally you would want construct
"HTTP::Request" or
"HTTP::Response" objects instead.
The optional $header argument should
be a reference to an "HTTP::Headers"
object or a plain array reference of key/value pairs. If an
"HTTP::Headers" object is provided
then a copy of it will be embedded into the constructed message, i.e. it
will not be owned and can be modified afterwards without affecting the
message.
The optional $content argument should
be a string of bytes.
- $mess = HTTP::Message->parse( $str )
- This constructs a new message object by parsing the given string.
- $mess->headers
- Returns the embedded "HTTP::Headers"
object.
- $mess->headers_as_string
- $mess->headers_as_string( $eol )
- Call the as_string() method for the headers in the message. This
will be the same as
$mess->headers->as_string
but it will make your program a whole character shorter
:-)
- $mess->content
- $mess->content( $bytes )
- The content() method sets the raw content if an argument is given.
If no argument is given the content is not touched. In either case the
original raw content is returned.
If the "undef" argument is
given, the content is reset to its default value, which is an empty
string.
Note that the content should be a string of bytes. Strings in
perl can contain characters outside the range of a byte. The
"Encode" module can be used to turn
such strings into a string of bytes.
- $mess->add_content( $bytes )
- The add_content() methods appends more data bytes to the end of the
current content buffer.
- $mess->add_content_utf8( $string )
- The add_content_utf8() method appends the UTF-8 bytes representing
the string to the end of the current content buffer.
- $mess->content_ref
- $mess->content_ref( \$bytes )
- The content_ref() method will return a reference to content buffer
string. It can be more efficient to access the content this way if the
content is huge, and it can even be used for direct manipulation of the
content, for instance:
${$res->content_ref} =~ s/\bfoo\b/bar/g;
This example would modify the content buffer in-place.
If an argument is passed it will setup the content to
reference some external source. The content() and
add_content() methods will automatically dereference scalar
references passed this way. For other references content() will
return the reference itself and add_content() will refuse to do
anything.
- $mess->content_charset
- This returns the charset used by the content in the message. The charset
is either found as the charset attribute of the
"Content-Type" header or by guessing.
See
<http://www.w3.org/TR/REC-html40/charset.html#spec-char-encoding>
for details about how charset is determined.
- $mess->decoded_content( %options )
- Returns the content with any
"Content-Encoding" undone and, for
textual content ("Content-Type" values
starting with "text/", exactly matching
"application/xml", or ending with
"+xml"), the raw content's character set
decoded into Perl's Unicode string format. Note that this does not
currently <https://github.com/libwww-perl/HTTP-Message/pull/99>
attempt to decode declared character sets for any other content types like
"application/json" or
"application/javascript". If the
"Content-Encoding" or
"charset" of the message is unknown,
this method will fail by returning
"undef".
The following options can be specified.
- "charset"
- This override the charset parameter for text content. The value
"none" can used to suppress decoding of
the charset.
- "default_charset"
- This override the default charset guessed by content_charset() or
if that fails "ISO-8859-1".
- "alt_charset"
- If decoding fails because the charset specified in the Content-Type header
isn't recognized by Perl's Encode module, then try decoding using this
charset instead of failing. The
"alt_charset" might be specified as
"none" to simply return the string
without any decoding of charset as alternative.
- "charset_strict"
- Abort decoding if malformed characters is found in the content. By default
you get the substitution character ("\x{FFFD}") in place of
malformed characters.
- "raise_error"
- If TRUE then raise an exception if not able to decode content. Reason
might be that the specified
"Content-Encoding" or
"charset" is not supported. If this
option is FALSE, then decoded_content() will return
"undef" on errors, but will still set
$@.
- "ref"
- If TRUE then a reference to decoded content is returned. This might be
more efficient in cases where the decoded content is identical to the raw
content as no data copying is required in this case.
- $mess->decodable
- HTTP::Message::decodable()
- This returns the encoding identifiers that decoded_content() can
process. In scalar context returns a comma separated string of
identifiers.
This value is suitable for initializing the
"Accept-Encoding" request header
field.
- $mess->decode
- This method tries to replace the content of the message with the decoded
version and removes the
"Content-Encoding" header. Returns TRUE
if successful and FALSE if not.
If the message does not have a
"Content-Encoding" header this method
does nothing and returns TRUE.
Note that the content of the message is still bytes after this
method has been called and you still need to call
decoded_content() if you want to process its content as a
string.
- $mess->encode( $encoding, ... )
- Apply the given encodings to the content of the message. Returns TRUE if
successful. The "identity" (non-)encoding is always supported;
other currently supported encodings, subject to availability of required
additional modules, are "gzip", "deflate",
"x-bzip2" and "base64".
A successful call to this function will set the
"Content-Encoding" header.
Note that "multipart/*" or
"message/*" messages can't be encoded
and this method will croak if you try.
- $mess->parts
- $mess->parts( @parts )
- $mess->parts( \@parts )
- Messages can be composite, i.e. contain other messages. The composite
messages have a content type of
"multipart/*" or
"message/*". This method give access to
the contained messages.
The argumentless form will return a list of
"HTTP::Message" objects. If the
content type of $msg is not
"multipart/*" or
"message/*" then this will return the
empty list. In scalar context only the first object is returned. The
returned message parts should be regarded as read-only (future versions
of this library might make it possible to modify the parent by modifying
the parts).
If the content type of $msg is
"message/*" then there will only be
one part returned.
If the content type is
"message/http", then the return value
will be either an "HTTP::Request" or
an "HTTP::Response" object.
If a @parts argument is given, then
the content of the message will be modified. The array reference form is
provided so that an empty list can be provided. The
@parts array should contain
"HTTP::Message" objects. The
@parts objects are owned by
$mess after this call and should not be modified
or made part of other messages.
When updating the message with this method and the old content
type of $mess is not
"multipart/*" or
"message/*", then the content type is
set to "multipart/mixed" and all other
content headers are cleared.
This method will croak if the content type is
"message/*" and more than one part is
provided.
- $mess->add_part( $part )
- This will add a part to a message. The $part
argument should be another
"HTTP::Message" object. If the previous
content type of $mess is not
"multipart/*" then the old content
(together with all content headers) will be made part #1 and the content
type made "multipart/mixed" before the
new part is added. The $part object is owned by
$mess after this call and should not be modified
or made part of other messages.
There is no return value.
- $mess->clear
- Will clear the headers and set the content to the empty string. There is
no return value
- $mess->protocol
- $mess->protocol( $proto )
- Sets the HTTP protocol used for the message. The protocol() is a
string like "HTTP/1.0" or
"HTTP/1.1".
- $mess->clone
- Returns a copy of the message object.
- $mess->as_string
- $mess->as_string( $eol )
- Returns the message formatted as a single string.
The optional $eol parameter specifies
the line ending sequence to use. The default is "\n". If no
$eol is given then as_string will ensure that
the returned string is newline terminated (even when the message content
is not). No extra newline is appended if an explicit
$eol is passed.
- $mess->dump( %opt )
- Returns the message formatted as a string. In void context print the
string.
This differs from
"$mess->as_string" in that it
escapes the bytes of the content so that it's safe to print them and it
limits how much content to print. The escapes syntax used is the same as
for Perl's double quoted strings. If there is no content the string
"(no content)" is shown in its place.
Options to influence the output can be passed as key/value
pairs. The following options are recognized:
- maxlength => $num
- How much of the content to show. The default is 512. Set this to 0 for
unlimited.
If the content is longer then the string is chopped at the
limit and the string "...\n(### more bytes not shown)"
appended.
- no_content => $str
- Replaces the "(no content)" marker.
- prefix => $str
- A string that will be prefixed to each line of the dump.
All methods unknown to
"HTTP::Message" itself are delegated to
the "HTTP::Headers" object that is part of
every message. This allows convenient access to these methods. Refer to
HTTP::Headers for details of these methods:
$mess->header( $field => $val )
$mess->push_header( $field => $val )
$mess->init_header( $field => $val )
$mess->remove_header( $field )
$mess->remove_content_headers
$mess->header_field_names
$mess->scan( \&doit )
$mess->date
$mess->expires
$mess->if_modified_since
$mess->if_unmodified_since
$mess->last_modified
$mess->content_type
$mess->content_encoding
$mess->content_length
$mess->content_language
$mess->title
$mess->user_agent
$mess->server
$mess->from
$mess->referer
$mess->www_authenticate
$mess->authorization
$mess->proxy_authorization
$mess->authorization_basic
$mess->proxy_authorization_basic
Gisle Aas <gisle@activestate.com>
This software is copyright (c) 1994 by Gisle Aas.
This is free software; you can redistribute it and/or modify it
under the same terms as the Perl 5 programming language system itself.