mime::field::conttype(3)
NAME
MIME::Field::ContType - a "Content-type" field
DESCRIPTION
A subclass of Mail::Field.
Don't use this class directly... its name may change in
the future! Instead, ask Mail::Field for new instances
based on the field name!
SYNOPSIS
use Mail::Field;
use MIME::Head;
# Create an instance from some text:
$field = Mail::Field->new('Content-type',
'text/HTML; charset="USASCII"');
# Get the MIME type, like 'text/plain' or 'x-foobar'.
# Returns 'text/plain' as default, as per RFC-1521:
my ($type, $subtype) = split('/', $field->type);
# Get generic information:
print $field->name;
# Get information related to "message" type:
if ($type eq 'message') {
print $field->id;
print $field->number;
print $field->total;
}
# Get information related to "multipart" type:
if ($type eq 'multipart') {
print $field->boundary; # the basic
value, fixed up
print $field->multipart_boundary; # empty if not
a multipart message!
}
# Get information related to "text" type:
if ($type eq 'text') {
print $field->charset; # returns 'us-ascii'
as default
}
PUBLIC INTERFACE
- boundary
- Return the boundary field. The boundary is returned
exactly as given in the "Content-type:" field; that
is, the leading double-hyphen ("--") is not prepended. - (Well, almost exactly... from RFC-1521:
(If a boundary appears to end with white space, thewhite space
must be presumed to have been added by a gateway,and must be deleted.) - so we oblige and remove any trailing spaces.)
- Returns the empty string if there is no boundary, or
if the boundary is illegal (e.g., if it is empty after
all trailing whitespace has been removed). - multipart_boundary
- Like "boundary()", except that this will also return
the empty string if the message is not a multipart
message. In other words, there's an automatic sanity
check. - type
- Try real hard to determine the content type (e.g.,
"text/plain", "image/gif", "x-weird-type", which is
returned in all-lowercase. - A happy thing: the following code will work just as
you would want, even if there's no subtype (as in
"x-weird-type")... in such a case, the $subtype would
simply be the empty string:
($type, $subtype) = split('/', $head->mime_type); - If the content-type information is missing, it
defaults to "text/plain", as per RFC-1521:
Default RFC-822 messages are typed by this protocol as plain text in
the US-ASCII character set, which can be explicitly specified as
"Content-type: text/plain; charset=us-ascii". Ifno Content-Type is
specified, this default is assumed. - Note: under the "be liberal in what we accept" princi
ple, this routine no longer syntax-checks the content
type. If it ain't empty, just downcase and return it.
NOTES
Since nearly all (if not all) parameters must have nonempty values to be considered valid, we just return the
empty string to signify missing fields. If you need to
get the real underlying value, use the inherited "param()"
method (which returns undef if the parameter is missing).
AUTHOR
- Eryq (eryq@zeegee.com), ZeeGee Software Inc
(http://www.zeegee.com).