Mail::Message::Head::Subset(3)

NAME
Mail::Message::Head::Subset - subset of header information of a message

INHERITANCE
 Mail::Message::Head::Subset realizes a Mail::Message::Head::Complete

 Mail::Message::Head::Subset
   is a Mail::Message::Head
   is a Mail::Reporter

SYNOPSIS
 my $subset = Mail::Message::Head::Subset->new(...)
 $subset->isa('Mail::Message::Head')  # true
 $subset->guessBodySize               # integer or undef
 $subset->isDelayed                   # true

DESCRIPTION
Some types of folders contain an index file which lists a few lines of information per messages. Especially when it is costly to read header lines, the index speeds-up access considerably. For instance, the subjects of all messages are often wanted, but waiting for a thousand messages of the folder to be read may imply a thousand network reads (IMAP) or file openings (MH)

When you access header fields which are not in the header subset, the whole header has to be parsed (which may consume considerable time, depending on the type of folder).

Extends "DESCRIPTION" in Mail::Message::Head.

OVERLOADED
Extends "OVERLOADED" in Mail::Message::Head.

overload: ""
    Inherited, see "OVERLOADED" in Mail::Message::Head

overload: bool
    Inherited, see "OVERLOADED" in Mail::Message::Head

METHODS
Extends "METHODS" in Mail::Message::Head.

  Constructors
Extends "Constructors" in Mail::Message::Head.

Mail::Message::Head::Subset->build( [PAIR|$field]-LIST )
    Inherited, see "Constructors" in Mail::Message::Head

Mail::Message::Head::Subset->new(%options)
    Inherited, see "Constructors" in Mail::Message::Head

  The header
Extends "The header" in Mail::Message::Head.

$obj->isDelayed()
    Inherited, see "The header" in Mail::Message::Head

$obj->isEmpty()
    Inherited, see "The header" in Mail::Message::Head

$obj->isModified()
    Inherited, see "The header" in Mail::Message::Head

$obj->knownNames()
    Inherited, see "The header" in Mail::Message::Head

$obj->message( [$message] )
    Inherited, see "The header" in Mail::Message::Head

$obj->modified( [BOOLEAN] )
    Inherited, see "The header" in Mail::Message::Head

$obj->orderedFields()
    Inherited, see "The header" in Mail::Message::Head

  Access to the header
Extends "Access to the header" in Mail::Message::Head.

$obj->count($name)
    Count the number of fields with this $name. If the $name cannot be found, the full header get loaded. In case we find any $name field, it is decided we know all of them, and loading is not needed.

$obj->get( $name, [$index] )
    Get the data which is related to the field with the $name. The case of the characters in $name does not matter. When a $name is used which is not known yet, realization will take place.

$obj->study( $name, [$index] )
    Inherited, see "Access to the header" in Mail::Message::Head

  About the body
Extends "About the body" in Mail::Message::Head.

$obj->guessBodySize()
    The body size is defined in the "Content-Length" field. However, this field may not be known. In that case, a guess is made based on the known "Lines" field. When also that field is not known yet, "undef" is returned.

$obj->isMultipart()
    Inherited, see "About the body" in Mail::Message::Head

  Internals
Extends "Internals" in Mail::Message::Head.

$obj->addNoRealize($field)
    Inherited, see "Internals" in Mail::Message::Head

$obj->addOrderedFields($fields)
    Inherited, see "Internals" in Mail::Message::Head

$obj->fileLocation()
    Inherited, see "Internals" in Mail::Message::Head

$obj->load()
    Inherited, see "Internals" in Mail::Message::Head

$obj->moveLocation($distance)
    Inherited, see "Internals" in Mail::Message::Head

$obj->read($parser)
    Inherited, see "Internals" in Mail::Message::Head

$obj->setNoRealize($field)
    Inherited, see "Internals" in Mail::Message::Head

  Error handling
Extends "Error handling" in Mail::Message::Head.

$obj->AUTOLOAD()
    Inherited, see "Error handling" in Mail::Reporter

$obj->addReport($object)
    Inherited, see "Error handling" in Mail::Reporter

$obj->defaultTrace( [$level]|[$loglevel, $tracelevel]|[$level, $callback] )
Mail::Message::Head::Subset->defaultTrace( [$level]|[$loglevel, $tracelevel]|[$level, $callback] )
    Inherited, see "Error handling" in Mail::Reporter

$obj->errors()
    Inherited, see "Error handling" in Mail::Reporter

$obj->log( [$level, [$strings]] )
Mail::Message::Head::Subset->log( [$level, [$strings]] )
    Inherited, see "Error handling" in Mail::Reporter

$obj->logPriority($level)
Mail::Message::Head::Subset->logPriority($level)
    Inherited, see "Error handling" in Mail::Reporter

$obj->logSettings()
    Inherited, see "Error handling" in Mail::Reporter

$obj->notImplemented()
    Inherited, see "Error handling" in Mail::Reporter

$obj->report( [$level] )
    Inherited, see "Error handling" in Mail::Reporter

$obj->reportAll( [$level] )
    Inherited, see "Error handling" in Mail::Reporter

$obj->trace( [$level] )
    Inherited, see "Error handling" in Mail::Reporter

$obj->warnings()
    Inherited, see "Error handling" in Mail::Reporter

  Cleanup
Extends "Cleanup" in Mail::Message::Head.

$obj->DESTROY()
    Inherited, see "Cleanup" in Mail::Reporter

DETAILS
Extends "DETAILS" in Mail::Message::Head.

DIAGNOSTICS

Error: Package $package does not implement $method.
    Fatal error: the specific package (or one of its superclasses) does not implement this method where it should. This message means that some other related classes do implement this method however the class at hand does not. Probably you should investigate this and probably inform the author of the package.

SEE ALSO
This module is part of Mail-Box distribution version 3.002, built on March 31, 2017.

Do not forget to read Mail::Box-Overview, Mail::Box-Cookbook, and Mail::Box-Index. Examples are included in the Mail-Box distribution, directories 'examples' and 'scripts'.

Browseable manuals, papers, and other released material van be found at Website: http://perl.overmeer.net/mailbox/

The central modules (in separate distributions) in the MailBox suite are: Mail::Message, Mail::Box, Mail::Box::IMAP4, Mail::Box::POP3, Mail::Box::Parser::C, Mail::Box::Dbx (unpublished), Mail::Transport, Object::Realize::Later, and User::Identity.

Please post questions or ideas to the author markov@cpan.org.

LICENSE
Copyrights 2001-2017 by [Mark Overmeer]. For other contributors see ChangeLog.

This program is free software; you can redistribute it and/or modify it under the Artistic license. See http://dev.perl.org/licenses/artistic.html