HTTP::Message - HTTP style message (base class)

version 6.33

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 the raw content encoded to Perl's Unicode strings. 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 [email protected]

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.