NAME

Mail::SpamAssassin::Message::Node - decode, render, and make available MIME message parts

DESCRIPTION

This module will encapsulate an email message and allow access to the various MIME message parts.

PUBLIC METHODS

new()

Generates an empty Node object and returns it. Typically only called by functions in Message.

find_parts()

Used to search the tree for specific MIME parts. An array of matching Node objects (pointers into the tree) is returned. The parameters that can be passed in are (in order, all scalars):

Regexp - Used to match against each part's Content-Type header, specifically the type and not the rest of the header. ie: "Content-type: text/html; encoding=quoted-printable" has a type of "text/html". If no regexp is specified, find_parts() will return an empty array.

Only_leaves - By default, find_parts() will return any part that matches the regexp, including multipart. If you only want to see leaves of the tree (ie: parts that aren't multipart), set this to true (1).

Recursive - By default, when find_parts() finds a multipart which has parts underneath it, it will recurse through all sub-children. If set to 0, only look at the part and any direct children of the part.

header()

Stores and retrieves headers from a specific MIME part. The first parameter is the header name. If there is no other parameter, the header is retrieved. If there is a second parameter, the header is stored.

Header names are case-insensitive and are stored in both raw and decoded form. Using header(), only the decoded form is retrievable.

For retrieval, if header() is called in an array context, an array will be returned with each header entry in a different element. In a scalar context, the last specific header is returned.

ie: If 'Subject' is specified as the header, and there are 2 Subject headers in a message, the last/bottom one in the message is returned in scalar context or both are returned in array context.

raw_header()

Retrieves the raw version of headers from a specific MIME part. The only parameter is the header name. Header names are case-insensitive.

For retrieval, if raw_header() is called in an array context, an array will be returned with each header entry in a different element. In a scalar context, the last specific header is returned.

ie: If 'Subject' is specified as the header, and there are 2 Subject headers in a message, the last/bottom one in the message is returned in scalar context or both are returned in array context.

add_body_part()

Adds a Node child object to the current node object.

is_leaf()

Returns true if the tree node in question is a leaf of the tree (ie: has no children of its own). Note: This function may return odd results unless the message has been mime parsed via _do_parse()!

raw()

Return a reference to the raw array. Treat this as READ ONLY.

decode()

If necessary, decode the part text as base64 or quoted-printable. The decoded text will be returned as a scalar string. An optional length parameter can be passed in which limits how much decoded data is returned. If the scalar isn't needed, call with "0" as a parameter.

decode_and_normalize()

Decode this part (as decode() does) and, where the declared character set allows it, transcode the result from bytes to perl characters.

Returns two scalars: the text, and a flag that is true when the text is in perl characters (utf8 flag on) and false when it is still bytes. Callers that do not care about the distinction can ignore the second value; those feeding the text to a parser that must be told which it is getting (e.g. Mail::SpamAssassin::HTML) need it.

Whether transcoding happens at all depends on the normalize_charset setting and on the declared charset: with normalization off, only text that is declared US-ASCII or UTF-8 and really does decode as UTF-8 is converted.

rendered()

Returns the rendered text for this part, as two scalars: the rendered type and the rendered text.

text/plain parts are rendered here (charset-decoded, see decode_and_normalize()). Every other type is rendered by its registered MIME-part handler, which publishes the result with set_rendered() during apply_handlers(); this method then just returns what the handler cached. text/html, for instance, is rendered by Mail::SpamAssassin::Handler::HTML.

Returns (undef,undef) for a part that is neither text/plain nor rendered by a handler -- including a text/html part reached before the handlers have run, or when no handler is registered for its type.

set_rendered($text, $type, $invisible, $visible)

Set the rendered text and type for the given part. If type is not specified, and text is a defined value, a default of 'text/plain' is used. This is how a MIME-part handler publishes the text it extracted, so that ordinary body rules can match it.

$invisible and $visible are optional. A caller whose renderer distinguishes text the recipient can see from text it cannot (currently Mail::SpamAssassin::Handler::HTML) passes both, where $text is everything and $visible is the visible subset. Omit them and all of $text counts as visible, with no invisible text -- the right answer for a renderer with no notion of hidden content, such as OCR or document text extraction.

visible_rendered()

Render and return the visible text in this part.

invisible_rendered()

Render and return the invisible text in this part.

content_summary()

Returns an array of scalars describing the mime parts of the message. Note: This function requires that the message be parsed first!

delete_header()

Delete the specified header (decoded and raw) from the Node information.

get_header()

Retrieve a specific header. Will have a newline at the end and will be unfolded. The first parameter is the header name (case-insensitive), and the second parameter (optional) is whether or not to return the raw header.

If get_header() is called in an array context, an array will be returned with each header entry in a different element. In a scalar context, the last specific header is returned.

ie: If 'Subject' is specified as the header, and there are 2 Subject headers in a message, the last/bottom one in the message is returned in scalar context or both are returned in array context.

Btw, returning the last header field (not the first) happens to be consistent with DKIM signatures, which search for and cover multiple header fields bottom-up according to the 'h' tag. Let's keep it this way.

get_all_headers()

Retrieve all headers. Each header will have a newline at the end and will be unfolded. The first parameter (optional) is whether or not to return the raw headers, and the second parameter (optional) is whether or not to include the mbox separator.

If get_all_header() is called in an array context, an array will be returned with each header entry in a different element. In a scalar context, the headers are returned in a single scalar.