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MIME::Field::ContType - a ``Content-type'' field
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!
use Mail::Field;
use MIME::Head;
# Create an instance from some text:
$field = Mail::Field->new('Content-type',
'text/HTML; charset="US-ASCII"');
# Get the MIME type, like 'text/plain' or 'x-foobar'.
# Returns 'text/plain' as default, as per RFC-1521:
my ($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
}
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, the white 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).
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.
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". If no Content-Type is
specified, this default is assumed.
Note: under the ``be liberal in what we accept'' principle, this routine no longer syntax-checks the content type. If it ain't empty, just downcase and return it.
Since nearly all (if not all) parameters must have non-empty 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).
Eryq (eryq@zeegee.com), ZeeGee Software Inc (http://www.zeegee.com). David F. Skoll (dfs@roaringpenguin.com) http://www.roaringpenguin.com