HTTP::Message - HTTP style message (base class)
version 7.00
use parent '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
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 overrides the charset parameter for text content. The value
none
can used to suppress decoding of the charset.
default_charset
This overrides 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", "base64" and "br".
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.