Provided by: libmail-box-perl_2.110-1_all 
NAME
Mail::Message::Body - the data of a body in a message
INHERITANCE
Mail::Message::Body has extra code in
Mail::Message::Body::Construct
Mail::Message::Body::Encode
Mail::Message::Body
is a Mail::Reporter
Mail::Message::Body is extended by
Mail::Message::Body::File
Mail::Message::Body::Lines
Mail::Message::Body::Multipart
Mail::Message::Body::Nested
Mail::Message::Body::String
Mail::Message::Body is realized by
Mail::Message::Body::Delayed
SYNOPSIS
my Mail::Message $msg = ...;
my $body = $msg->body;
my @text = $body->lines;
my $text = $body->string;
my $file = $body->file; # IO::File
$body->print(\*FILE);
my $content_type = $body->type;
my $transfer_encoding = $body->transferEncoding;
my $encoded = $body->encode(mime_type => 'text/html',
charset => 'us-ascii', transfer_encoding => 'none');\n";
my $decoded = $body->decoded;
DESCRIPTION
The encoding and decoding functionality of a Mail::Message::Body is implemented in the
Mail::Message::Body::Encode package. That package is automatically loaded when encoding and decoding of
messages needs to take place. Methods to simply build an process body objects are implemented in
Mail::Message::Body::Construct.
The body of a message (a Mail::Message object) is stored in one of the many body types. The
functionality of each body type is equivalent, but there are performance differences. Each body type has
its own documentation with details about its implementation.
See documentation in the base class.
OVERLOADED
overload: ""()
(stringification) Returns the body as string --which will trigger completion-- unless called to
produce a string for "Carp". The latter to avoid deep recursions.
example: stringification of body
print $msg->body; # implicit by print
my $body = $msg->body;
my $x = "$body"; # explicit by interpolation
overload: '==' and '!='()
(numeric comparison) compares if two references point to the same message. This only produces
correct results is both arguments are message references within the same folder.
example: use of numeric comparison on a body
my $skip = $folder->message(3);
foreach my $msg (@$folder)
{ next if $msg == $skip;
$msg->send;
}
overload: @{}()
When a body object is used as being an array reference, the lines of the body are returned. This is
the same as using lines().
example: using a body as array
print $body->lines->[1]; # second line
print $body->[1]; # same
my @lines = $body->lines;
my @lines = @$body; # same
overload: bool()
Always returns a true value, which is needed to have overloaded objects to be used as in "if($body)".
Otherwise, "if(defined $body)" would be needed to avoid a runtime error.
METHODS
See documentation in the base class.
Constructors
See documentation in the base class.
$obj->clone()
Return a copy of this body, usually to be included in a cloned message. Use Mail::Message::clone()
for a whole message.
Mail::Message::Body->new(OPTIONS)
BE WARNED that, what you specify here are encodings and such which are already in place. The options
will not trigger conversions. When you need conversions, first create a body with options which tell
what you've got, and then call encode() for what you need.
-Option --Defined in --Default
based_on undef
charset 'PERL' or <undef>
checked <false>
content_id undef
data undef
description undef
disposition undef
eol 'NATIVE'
file undef
log Mail::Reporter 'WARNINGS'
message undef
mime_type 'text/plain'
modified <false>
trace Mail::Reporter 'WARNINGS'
transfer_encoding 'none'
based_on => BODY
The information about encodings must be taken from the specified BODY, unless specified
differently.
charset => CHARSET|'PERL'
Defines the character-set which is used in the data. Only useful in combination with a "mime_type"
which refers to "text" in any shape, which does not contain an explicit charset already. This
field is case-insensitive.
When a known CHARSET is provided and the mime type says "text", then the data is expected to be
bytes in that particular encoding (see Encode). When 'PERL' is given, then then the data is in
Perl's internal encoding (either latin1 or utf8, you shouldn't know!) More details in "Character
encoding PERL"
checked => BOOLEAN
Whether the added information has been check not to contain illegal octets with respect to the
transfer encoding and mime type. If not checked, and then set as body for a message, it will be.
content_id => STRING
In multipart/related MIME content, the content_id is required to allow access to the related
content via a cid:<...> descriptor of an inline disposition.
A "Content-ID" is supposed to be globally unique. As such, it is common to append
'@computer.domain' to the end of some unique string. As other content in the multipart/related
container also needs to know what this "Content-ID" is, this should be left to the imagination of
the person making the content (for now).
As a MIME header field, the "Content-ID" string is expected to be inside angle brackets
data => ARRAY-OF-LINES | STRING
The content of the body. The only way to set the content of a body is during the creation of the
body. So if you want to modify the content of a message, you need to create a new body with the
new content and add that to the body. The reason behind this, is that correct encodings and body
information must be guaranteed. It avoids your hassle in calculating the number of lines in the
body, and checking whether bad characters are enclosed in text.
Specify a reference to an ARRAY of lines, each terminated by a newline. Or one STRING which may
contain multiple lines, separated and terminated by a newline.
description => STRING|FIELD
Informal information about the body content. The data relates to the "Content-Description" field.
Specify a STRING which will become the field content, or a real FIELD.
disposition => STRING|FIELD
How this message can be decomposed. The data relates to the "Content-Disposition" field. Specify
a STRING which will become the field content, or a real FIELD.
The content of this field is specified in RFC 1806. The body of the field can be "inline", to
indicate that the body is intended to be displayed automatically upon display of the message. Use
"attachment" to indicate that they are separate from the main body of the mail message, and that
their display should not be automatic, but contingent upon some further action of the user.
The "filename" attribute specifies a name to which is suggested to the reader of the message when
it is extracted.
eol => 'CR'|'LF'|'CRLF'|'NATIVE'
Convert the message into having the specified string as line terminator for all lines in the body.
"NATIVE" is used to represent the "\n" on the current platform and will be translated in the
applicable one.
BE WARNED that folders with a non-native encoding may appear on your platform, for instance in
Windows folders handled from a UNIX system. The eol encoding has effect on the size of the body!
file => FILENAME|FILEHANDLE|IOHANDLE
Read the data from the specified file, file handle, or object of type "IO::Handle".
log => LEVEL
message => MESSAGE
The message where this body belongs to.
mime_type => STRING|FIELD|MIME
The type of data which is added. You may specify a content of a header line as STRING, or a FIELD
object. You may also specify a MIME::Type object. In any case, it will be kept internally as a
real field (a Mail::Message::Field object). This relates to the "Content-Type" header field.
A mime-type specification consists of two parts: a general class ("text", "image", "application",
etc) and a specific sub-class. Examples for specific classes with "text" are "plain", "html", and
"xml". This field is case-insensitive but case preserving. The default mime-type is "text/plain",
modified => BOOLEAN
Whether the body is flagged modified, directly from its creation.
trace => LEVEL
transfer_encoding => STRING|FIELD
The encoding that the data has. If the data is to be encoded, than you will have to call encode()
after the body is created. That will return a new encoded body. This field is case-insensitive
and relates to the "Content-Transfer-Encoding" field in the header.
example:
my $body = Mail::Message::Body::String->new(file => \*IN,
mime_type => 'text/html; charset="ISO-8859-1"');
my $body = Mail::Message::Body::Lines->new(data => ['first', $second],
charset => 'ISO-10646', transfer_encoding => 'none');
my $body = Mail::Message::Body::Lines->new(data => \@lines,
transfer_encoding => 'base64');
my $body = Mail::Message::Body::Lines->new(file => 'picture.gif',
mime_type => 'image/gif', content_id => '<12345@example.com>',
disposition => 'inline');
Constructing a body
$obj->attach(MESSAGES, OPTIONS)
See "Constructing a body" in Mail::Message::Body::Construct
$obj->check()
See "Constructing a body" in Mail::Message::Body::Encode
$obj->concatenate(COMPONENTS)
See "Constructing a body" in Mail::Message::Body::Construct
$obj->decoded(OPTIONS)
Returns a body, an object which is (a sub-)class of a Mail::Message::Body, which contains a
simplified representation of textual data. The returned object may be the object where this is
called on, but may also be a new body of any type.
my $dec = $body->decoded;
is equivalent with
my $dec = $body->encode
( mime_type => 'text/plain'
, transfer_encoding => 'none'
, charset => 'PERL'
);
The $dec which is returned is a body. Ask with the mimeType() method what is produced. This $dec
body is not related to a header.
-Option --Default
result_type <same as current>
result_type => CLASS
$obj->encode(OPTIONS)
See "Constructing a body" in Mail::Message::Body::Encode
$obj->encoded()
See "Constructing a body" in Mail::Message::Body::Encode
$obj->eol(['CR'|'LF'|'CRLF'|'NATIVE'])
Returns the character (or characters) which are used to separate lines within this body. When a kind
of separator is specified, the body is translated to contain the specified line endings.
example:
my $body = $msg->decoded->eol('NATIVE');
my $char = $msg->decoded->eol;
$obj->foreachLine(CODE)
See "Constructing a body" in Mail::Message::Body::Construct
$obj->stripSignature(OPTIONS)
See "Constructing a body" in Mail::Message::Body::Construct
$obj->unify(BODY)
See "Constructing a body" in Mail::Message::Body::Encode
The body
$obj->isDelayed()
Returns a true or false value, depending on whether the body of this message has been read from file.
This can only false for a Mail::Message::Body::Delayed.
$obj->isMultipart()
Returns whether this message-body contains parts which are messages by themselves.
$obj->isNested()
Only true for a message body which contains exactly one sub-message: the
"Mail::Message::Body::Nested" body type.
$obj->message([MESSAGE])
Returns the message (or message part) where this body belongs to, optionally setting it to a new
MESSAGE first. If "undef" is passed, the body will be disconnected from the message.
$obj->partNumberOf(PART)
Returns a string for multiparts and nested, otherwise an error. It is used in
Mail::Message::partNumber().
About the payload
$obj->charset()
Returns the character set which is used in the text body as string. This is part of the result of
what the "type" method returns.
$obj->checked([BOOLEAN])
Returns whether the body encoding has been checked or not (optionally after setting the flag to a new
value).
$obj->contentId([STRING|FIELD])
Returns (optionally after setting) the id (unique reference) of a message part. The related header
field is "Content-ID". A Mail::Message::Field object is returned (which stringifies into the field
content). The field content will be "none" if no disposition was specified.
The argument can be a STRING (which is converted into a field), or a fully prepared header FIELD.
$obj->description([STRING|FIELD])
Returns (optionally after setting) the informal description of the body content. The related header
field is "Content-Description". A Mail::Message::Field object is returned (which stringifies into
the field content). The field content will be "none" if no disposition was specified.
The argument can be a STRING (which is converted into a field), or a fully prepared header field.
$obj->disposition([STRING|FIELD])
Returns (optionally after setting) how the message can be disposed (unpacked). The related header
field is "Content-Disposition". A Mail::Message::Field object is returned (which stringifies into
the field content). The field content will be "none" if no disposition was specified.
The argument can be a STRING (which is converted into a field), or a fully prepared header field.
$obj->dispositionFilename([DIRECTORY])
See "About the payload" in Mail::Message::Body::Encode
$obj->isBinary()
See "About the payload" in Mail::Message::Body::Encode
$obj->isText()
See "About the payload" in Mail::Message::Body::Encode
$obj->mimeType()
Returns a MIME::Type object which is related to this body's type. This differs from the "type"
method, which results in a Mail::Message::Field.
example:
if($body->mimeType eq 'text/html') {...}
print $body->mimeType->simplified;
$obj->nrLines()
Returns the number of lines in the message body. For multi-part messages, this includes the header
lines and boundaries of all the parts.
$obj->size()
The total number of bytes in the message body. The size of the body is computed in the shape it is
in. For example, if this is a base64 encoded message, the size of the encoded data is returned; you
may want to call Mail::Message::decoded() first.
$obj->transferEncoding([STRING|FIELD])
Returns the transfer-encoding of the data within this body as Mail::Message::Field (which stringifies
to its content). If it needs to be changed, call the encode() or decoded() method. When no encoding
is present, the field contains the text "none".
The optional STRING or FIELD enforces a new encoding to be set, without the actual required
translations.
example:
my $transfer = $msg->decoded->transferEncoding;
$transfer->print; # --> Content-Encoding: base64
print $transfer; # --> base64
if($msg->body->transferEncoding eq 'none') {...}
$obj->type([STRING|FIELD])
Returns the type of information the body contains as Mail::Message::Field object. The type is taken
from the header field "Content-Type". If the header did not contain that field, then you will get a
default field containing "text/plain".
You usually can better use mimeType(), because that will return a clever object with type
information.
example:
my $msg = $folder->message(6);
$msg->get('Content-Type')->print;
# --> Content-Type: text/plain; charset="us-ascii"
my $content = $msg->decoded;
my $type = $content->type;
print "This is a $type message\n";
# --> This is a text/plain; charset="us-ascii" message
print "This is a ", $type->body, "message\n";
# --> This is a text/plain message
print "Comment: ", $type->comment, "\n";
# --> Comment: charset="us-ascii"
Access to the payload
$obj->endsOnNewline()
Returns whether the last line of the body is terminated by a new-line (in transport it will become a
CRLF). An empty body will return true as well: the newline comes from the line before it.
$obj->file()
Return the content of the body as a file handle. The returned stream may be a real file, or a
simulated file in any form that Perl supports. While you may not be able to write to the file
handle, you can read from it.
WARNING: Even if the file handle supports writing, do not write to the file handle. If you do, some
of the internal values of the Mail::Message::Body may not be updated.
$obj->lines()
Return the content of the body as a list of lines (in LIST context) or a reference to an array of
lines (in SCALAR context). In scalar context the array of lines is cached to avoid needless copying
and therefore provide much faster access for large messages.
To just get the number of lines in the body, use the nrLines() method, which is usually much more
efficient.
BE WARNED: For some types of bodies the reference will refer to the original data. You must not
change the referenced data! If you do, some of the essential internal variables of the
Mail::Message::Body may not be updated.
example:
my @lines = $body->lines; # copies lines
my $line3 = ($body->lines)[3] # only one copy
print $lines[0];
my $linesref = $body->lines; # reference to originals
my $line3 = $body->lines->[3] # only one copy (faster)
print $linesref->[0];
print $body->[0]; # by overloading
$obj->print([FILEHANDLE])
Print the body to the specified FILEHANDLE (defaults to the selected handle). The handle may be a
GLOB, an IO::File object, or... any object with a "print()" method will do. Nothing useful is
returned.
$obj->printEscapedFrom(FILEHANDLE)
Print the body to the specified FILEHANDLE but all lines which start with 'From ' (optionally already
preceded by >'s) will habe an > added in front. Nothing useful is returned.
$obj->string()
Return the content of the body as a scalar (a single string). This is a copy of the internally kept
information.
example:
my $text = $body->string;
print "Body: $body\n"; # by overloading
$obj->stripTrailingNewline()
Remove the newline from the last line, or the last line if it does not contain anything else than a
newline.
$obj->write(OPTIONS)
Write the content of the body to a file. Be warned that you may want to decode the body before
writing it!
-Option --Default
filename <required>
filename => FILENAME
example: write the data to a file
use File::Temp;
my $fn = tempfile;
$message->decoded->write(filename => $fn)
or die "Couldn't write to $fn: $!\n";
example: using the content-disposition information to write
use File::Temp;
my $dir = tempdir; mkdir $dir or die;
my $fn = $message->body->dispositionFilename($dir);
$message->decoded->write(filename => $fn)
or die "Couldn't write to $fn: $!\n";
Internals
$obj->addTransferEncHandler(NAME, CLASS|OBJECT)
Mail::Message::Body->addTransferEncHandler(NAME, CLASS|OBJECT)
See "Internals" in Mail::Message::Body::Encode
$obj->contentInfoFrom(HEAD)
Transfer the body related info from the header into this body.
$obj->contentInfoTo(HEAD)
Copy the content information (the "Content-*" fields) into the specified HEAD. The body was created
from raw data without the required information, which must be added. See also contentInfoFrom().
$obj->fileLocation([BEGIN,END])
The location of the body in the file. Returned a list containing begin and end. The begin is the
offsets of the first byte if the folder used for this body. The end is the offset of the first byte
of the next message.
$obj->getTransferEncHandler(TYPE)
See "Internals" in Mail::Message::Body::Encode
$obj->isModified()
Returns whether the body has changed.
$obj->load()
Be sure that the body is loaded. This returns the loaded body.
$obj->modified([BOOLEAN])
Change the body modification flag. This will force a re-write of the body to a folder file when it
is closed. It is quite dangerous to change the body: the same body may be shared between messages
within your program.
Especially be warned that you have to change the message-id when you change the body of the message:
no two messages should have the same id.
Without value, the current setting is returned, although you can better use isModified().
$obj->moveLocation([DISTANCE])
Move the registration of the message to a new location over DISTANCE. This is called when the
message is written to a new version of the same folder-file.
$obj->read(PARSER, HEAD, BODYTYPE [,CHARS [,LINES]])
Read the body with the PARSER from file. The implementation of this method will differ between types
of bodies. The BODYTYPE argument is a class name or a code reference of a routine which can produce
a class name, and is used in multipart bodies to determine the type of the body for each part.
The CHARS argument is the estimated number of bytes in the body, or "undef" when this is not known.
This data can sometimes be derived from the header (the "Content-Length" line) or file-size.
The second argument is the estimated number of LINES of the body. It is less useful than the CHARS
but may be of help determining whether the message separator is trustworthy. This value may be found
in the "Lines" field of the header.
Error handling
See documentation in the base class.
$obj->AUTOLOAD()
When an unknown method is called on a message body object, this may not be problematic. For
performance reasons, some methods are implemented in separate files, and only demand-loaded. If this
delayed compilation of additional modules does not help, an error will be produced.
$obj->addReport(OBJECT)
See "Error handling" in Mail::Reporter
$obj->defaultTrace([LEVEL]|[LOGLEVEL, TRACELEVEL]|[LEVEL, CALLBACK])
Mail::Message::Body->defaultTrace([LEVEL]|[LOGLEVEL, TRACELEVEL]|[LEVEL, CALLBACK])
See "Error handling" in Mail::Reporter
$obj->errors()
See "Error handling" in Mail::Reporter
$obj->log([LEVEL [,STRINGS]])
Mail::Message::Body->log([LEVEL [,STRINGS]])
See "Error handling" in Mail::Reporter
$obj->logPriority(LEVEL)
Mail::Message::Body->logPriority(LEVEL)
See "Error handling" in Mail::Reporter
$obj->logSettings()
See "Error handling" in Mail::Reporter
$obj->notImplemented()
See "Error handling" in Mail::Reporter
$obj->report([LEVEL])
See "Error handling" in Mail::Reporter
$obj->reportAll([LEVEL])
See "Error handling" in Mail::Reporter
$obj->trace([LEVEL])
See "Error handling" in Mail::Reporter
$obj->warnings()
See "Error handling" in Mail::Reporter
Cleanup
See documentation in the base class.
$obj->DESTROY()
See "Cleanup" in Mail::Reporter
DETAILS
Access to the body
A body can be contained in a message, but may also live without a message. In both cases it stores data,
and the same questions can be asked: what type of data it is, how many bytes and lines, what encoding is
used. Any body can be encoded and decoded, returning a new body object. However, bodies which are part
of a message will always be in a shape that they can be written to a file or send to somewhere: they will
be encoded if needed.
Body class implementation
The body of a message can be stored in many ways. Roughly, the implementations can be split in two
groups: the data collectors and the complex bodies. The primer implement various ways to access data, and
are full compatible: they only differ in performance and memory footprint under different circumstances.
The latter are created to handle complex multiparts and lazy extraction.
Data collector bodies
• Mail::Message::Body::String
The whole message body is stored in one scalar. Small messages can be contained this way without
performance penalties.
• Mail::Message::Body::Lines
Each line of the message body is stored as single scalar. This is a useful representation for a
detailed look in the message body, which is usually line-organized.
• Mail::Message::Body::File
The message body is stored in an external temporary file. This type of storage is especially useful
when the body is large, the total folder is large, or memory is limited.
• Mail::Message::Body::InFolder
NOT IMPLEMENTED YET. The message is kept in the folder, and is only taken out when the content is
changed.
• Mail::Message::Body::External
NOT IMPLEMENTED YET. The message is kept in a separate file, usually because the message body is
large. The difference with the "::External" object is that this external storage stays this way
between closing and opening of a folder. The "::External" object only uses a file when the folder is
open.
Complex bodies
• Mail::Message::Body::Delayed
The message-body is not yet read, but the exact location of the body is known so the message can be
read when needed. This is part of the lazy extraction mechanism. Once extracted, the object can
become any simple or complex body.
• Mail::Message::Body::Multipart
The message body contains a set of sub-messages (which can contain multipart bodies themselves).
Each sub-message is an instance of Mail::Message::Part, which is an extension of Mail::Message.
• Mail::Message::Body::Nested
Nested messages, like "message/rfc822": they contain a message in the body. For most code, they
simply behave like multiparts.
Character encoding PERL
A body object can be part of a message, or stand-alone. In case it is a part of a message, the
"transport encoding" and the content must be in a shape that the data can be transported via SMTP.
However, when you want to process the body data in simple Perl (or when you construct the body data from
normal Perl strings), you need to be aware of Perl's internal representation of strings. That can either
be latin1 or utf8 (not real UTF-8, but something alike, see the perlunicode manual page) So, before you
start using the data from an incoming message, do
my $body = $msg->decoded;
my @lines = $body->lines;
Now, the body has character-set 'PERL' (when it is text)
When you create a new body which contains text content (the default), it will be created with character-
set 'PERL' unless you specify a character-set explicitly.
my $body = Mail::Box::Body::Lines->new(data => \@lines);
# now mime=text/plain, charset=PERL
my $msg = Mail::Message->buildFromBody($body);
$msg->body($body);
$msg->attach($body); # etc
# these all will convert the charset=PERL into real utf-8
DIAGNOSTICS
Warning: Charset $name is not known
The encoding or decoding of a message body encounters a character set which is not understood by
Perl's Encode module.
Warning: No decoder defined for transfer encoding $name.
The data (message body) is encoded in a way which is not currently understood, therefore no decoding
(or recoding) can take place.
Warning: No encoder defined for transfer encoding $name.
The data (message body) has been decoded, but the required encoding is unknown. The decoded data is
returned.
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.
Warning: Unknown line terminator $eol ignored
SEE ALSO
This module is part of Mail-Box distribution version 2.110, built on January 05, 2014. Website:
http://perl.overmeer.net/mailbox/
LICENSE
Copyrights 2001-2014 by [Mark Overmeer]. For other contributors see ChangeLog.
This program is free software; you can redistribute it and/or modify it under the same terms as Perl
itself. See http://www.perl.com/perl/misc/Artistic.html