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.
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¶
Constructors¶
- $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>
- $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 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.
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>
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¶
- $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¶
- $obj->DESTROY()
- See "Cleanup" in Mail::Reporter
- $obj->inGlobalDestruction()
- 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 2.105, built on May 07,
2012. Website:
http://perl.overmeer.net/mailbox/
LICENSE¶
Copyrights 2001-2012 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