BodyStructure(3p)

NAME
Mail::IMAPClient::BodyStructure - Perl extension to Mail::IMAPClient to facilitate the parsing of server responses to the FETCH BODYSTRUCTURE and FETCH ENVELOPE IMAP client commands.

SYNOPSIS
  use Mail::IMAPClient::BodyStructure;
  use Mail::IMAPClient;

  my $imap = Mail::IMAPClient->new(Server=>$serv,User=>$usr,Password=>$pwd);
  $imap->select("INBOX") or die "cannot select the inbox for $usr: $@\n";

  my @recent = $imap->search("recent");

  foreach my $new (@recent) {

        my $struct = Mail::IMAPClient::BodyStructure->new(
                        $imap->fetch($new,"bodystructure")
        );

        print   "Msg $new (Content-type: ",$struct->bodytype,"/",$struct->bodysubtype,
                ") contains these parts:\n\t",join("\n\t",$struct->parts),"\n\n";

  }

DESCRIPTION
This extension will parse the result of an IMAP FETCH BODYSTRUCTURE command into a perl data structure. It also provides helper methods that will help you pull information out of the data structure.

Use of this extension requires Parse::RecDescent. If you don't have Parse::RecDescent then you must either get it or refrain from using this module.

  EXPORT
Nothing is exported by default. $parser is exported upon request. $parser is the BodyStucture object's Parse::RecDescent object, which you'll probably only need for debugging purposes.

Class Methods
The following class method is available:

  new
This class method is the constructor method for instantiating new Mail::IMAPClient::BodyStructure objects. The new method accepts one argument, a string containing a server response to a FETCH BODYSTRUCTURE directive. Only one message's body structure should be described in this string, although that message may contain an arbitrary number of parts.

If you know the messages sequence number or unique ID (UID) but haven't got its body structure, and you want to get the body structure and parse it into a Mail::IMAPClient::BodyStructure object, then you might as well save yourself some work and use Mail::IMAPClient's get_bodystructure method, which accepts a message sequence number (or UID if Uid is true) and returns a Mail::IMAPClient::BodyStructure object. It's functionally equivalent to issuing the FETCH BODYSTRUCTURE IMAP client command and then passing the results to Mail::IMAPClient::BodyStructure's new method but it does those things in one simple method call.

Object Methods
The following object methods are available:

  bodytype
The bodytype object method requires no arguments. It returns the bodytype for the message whose structure is described by the calling Mail::IMAPClient::Bodystructure object.

  bodysubtype
The bodysubtype object method requires no arguments. It returns the bodysubtype for the message whose structure is described by the calling Mail::IMAPClient::Bodystructure object.

  bodyparms
The bodyparms object method requires no arguments. It returns the bodyparms for the message whose structure is described by the calling Mail::IMAPClient::Bodystructure object.

  bodydisp
The bodydisp object method requires no arguments. It returns the bodydisp for the message whose structure is described by the calling Mail::IMAPClient::Bodystructure object.

  bodyid
The bodyid object method requires no arguments. It returns the bodyid for the message whose structure is described by the calling Mail::IMAPClient::Bodystructure object.

  bodydesc
The bodydesc object method requires no arguments. It returns the bodydesc for the message whose structure is described by the calling Mail::IMAPClient::Bodystructure object.

  bodyenc
The bodyenc object method requires no arguments. It returns the bodyenc for the message whose structure is described by the calling Mail::IMAPClient::Bodystructure object.

  bodysize
The bodysize object method requires no arguments. It returns the bodysize for the message whose structure is described by the calling Mail::IMAPClient::Bodystructure object.

  bodylang
The bodylang object method requires no arguments. It returns the bodylang for the message whose structure is described by the calling Mail::IMAPClient::Bodystructure object.

  bodystructure
The bodystructure object method requires no arguments. It returns the bodystructure for the message whose structure is described by the calling Mail::IMAPClient::Bodystructure object.

  envelopestruct
The envelopestruct object method requires no arguments. It returns the envelopestruct for the message whose structure is described by the calling Mail::IMAPClient::Bodystructure object. This envelope structure is blessed into the Mail::IMAPClient::BodyStructure::Envelope subclass, which is explained more fully below.

  textlines
The textlines object method requires no arguments. It returns the textlines for the message whose structure is described by the calling Mail::IMAPClient::Bodystructure object.

Envelopes and the Mail::IMAPClient::BodyStructure::Envelope Subclass
The IMAP standard specifies that output from the IMAP FETCH ENVELOPE command will be an RFC2060 envelope structure. It further specifies that output from the FETCH BODYSTRUCTURE command may also contain embedded envelope structures (if, for example, a message's subparts contain one or more included messages). Objects belonging to Mail::IMAPClient::BodyStructure::Envelope are Perl representations of these envelope structures, which is to say the nested parenthetical lists of RFC2060 translated into a Perl datastructure.

Note that all of the fields relate to the specific part to which they belong. In other words, output from a FETCH nnnn ENVELOPE command (or, in Mail::IMAPClient, "$imap-"fetch($msgid,"ENVELOPE")> or "my $env = $imap-"get_envelope($msgid)>) are for the message, but fields from within a bodystructure relate to the message subpart and not the parent message.

An envelope structure's Mail::IMAPClient::BodyStructure::Envelope representation is a hash of thingies that looks like this:

{
                     subject =>     "subject",
                     inreplyto =>    "reference_message_id",
                     from =>     [ addressStruct1 ],
                     messageid =>     "message_id",
                     bcc =>     [ addressStruct1, addressStruct2 ],
                     date =>     "Tue, 09 Jul 2002 14:15:53 -0400",
                     replyto =>     [ adressStruct1, addressStruct2 ],
                     to =>     [ adressStruct1, addressStruct2 ],
                     sender =>     [ adressStruct1 ],
                     cc =>     [ adressStruct1, addressStruct2 ],
}

The ...::Envelope object also has methods for accessing data in the structure. They are:

date
    Returns the date of the message.

inreplyto
    Returns the message id of the message to which this message is a reply.

subject
    Returns the subject of the message.

messageid
    Returns the message id of the message.

You can also use the following methods to get addressing information. Each of these methods returns an array of Mail::IMAPClient::BodyStructure::Address objects, which are perl data structures representing RFC2060 address structures. Some of these arrays would naturally contain one element (such as from, which normally contains a single "From:" address); others will often contain more than one address. However, because RFC2060 defines all of these as "lists of address structures", they are all translated into arrays of ...::Address objects.

See the section on Mail::IMAPClient::BodyStructure::Address", below, for alternate (and preferred) ways of accessing these data.

The methods available are:

bcc Returns an array of blind cc'ed recipients' address structures. (Don't expect much in here unless the message was sent from the mailbox you're poking around in, by the way.)

cc  Returns an array of cc'ed recipients' address structures.

from
    Returns an array of "From:" address structures--usually just one.

replyto
    Returns an array of "Reply-to:" address structures. Once again there is usually just one address in the list.

sender
    Returns an array of senders' address structures--usually just one and usually the same as from.

to  Returns an array of recipients' address structures.

Each of the methods that returns a list of address structures (i.e. a list of Mail::IMAPClient::BodyStructure::Address arrays) also has an analagous method that will return a list of E-Mail addresses instead. The addresses are in the format "personalname <mailboxname@hostname>" (see the section on Mail::IMAPClient::BodyStructure::Address, below) However, if the personal name is 'NIL' then it is omitted from the address.

These methods are:

bcc_addresses
    Returns a list (or an array reference if called in scalar context) of blind cc'ed recipients' email addresses. (Don't expect much in here unless the message was sent from the mailbox you're poking around in, by the way.)

cc_addresses
    Returns a list of cc'ed recipients' email addresses. If called in a scalar context it returns a reference to an array of email addresses.

from_addresses
    Returns a list of "From:" email addresses. If called in a scalar context it returns the first email address in the list. (It's usually a list of just one anyway.)

replyto_addresses
    Returns a list of "Reply-to:" email addresses. If called in a scalar context it returns the first email address in the list.

sender_addresses
    Returns a list of senders' email addresses. If called in a scalar context it returns the first email address in the list.

to_addresses
    Returns a list of recipients' email addresses. If called in a scalar context it returns a reference to an array of email addresses.

Note that context affects the behavior of all of the above methods.

Those fields that will commonly contain multiple entries (i.e. they are recipients) will return an array reference when called in scalar context. You can use this behavior to optimize performance.

Those fields that will commonly contain just one address (the sender's) will return the first (and usually only) address. You can use this behavior to optimize your development time.

Addresses and the Mail::IMAPClient::BodyStructure::Address
Several components of an envelope structure are address structures. They are each parsed into their own object, Mail::IMAPClient::BodyStructure::Address, which looks like this:

          {
            mailboxname         => 'somebody.special',
            hostname            => 'somplace.weird.com',
            personalname        => 'Somebody Special
            sourceroute         => 'NIL'
          }

RFC2060 specifies that each address component of a bodystructure is a list of address structures, so Mail::IMAPClient::BodyStructure parses each of these into an array of Mail::IMAPClient::BodyStructure::Address objects.

Each of these objects has the following methods available to it:

mailboxname
    Returns the "mailboxname" portion of the address, which is the part to the left of the '@' sign.

hostname
    Returns the "hostname" portion of the address, which is the part to the right of the '@' sign.

personalname
    Returns the "personalname" portion of the address, which is the part of the address that's treated like a comment.

sourceroute
    Returns the "sourceroute" portion of the address, which is typically "NIL".

Taken together, the parts of an address structure form an address that will look something like this:

"personalname <mailboxname@hostname>"

Note that because the Mail::IMAPClient::BodyStructure::Address objects come in arrays, it's generally easier to use the methods available to Mail::IMAPClient::BodyStructure::Envelope to obtain all of the addresses in a particular array in one operation. These methods are provided, however, in case you'd rather do things the hard way. (And also because the aforementioned methods from Mail::IMAPClient::BodyStructure::Envelope need them anyway.)

AUTHOR
David J. Kernen

SEE ALSO
perl(1), Mail::IMAPClient, and RFC2060. See also Parse::RecDescent if you want to understand the internals of this module.