VOTABLE::OPTION - VOTABLE OPTION XML element class
use VOTABLE::OPTION;
This class implements the OPTION
element from the VOTABLE
DTD. This element is used to enumerate multiple possible values for an
item.
The OPTION
element is a Tier 1 element, and is described by the
following excerpt from the VOTABLE
1.0 DTD:
<!ELEMENT OPTION (OPTION*)> <!ATTLIST OPTION name CDATA #IMPLIED value CDATA #REQUIRED >
new($xmldom_element, %options)
Create and return a new VOTABLE::OPTION
object, based on the
supplied XML::DOM::Element
object, using %options
to set the
attributes of the new object. If no XML::DOM::Element
object is
specified, or is undefined, create and return an empty
VOTABLE::OPTION
object. Return undef if an error occurs.
get_name
Return the value of the name
attribute. Return undef
if the
attribute has not been set, or an error occurs.
set_name($name)
Set the value of the name
attribute to the specified value. Return
the new value of the attribute on success, or undef
if an error
occurs.
get_value
Return the value of the value
attribute. Return undef
if the
attribute has not been set, or an error occurs.
set_value($value)
Set the value of the value
attribute to the specified value. Return
the new value of the attribute on success, or undef
if an error
occurs.
_
') are for
internal use only, and should not be used outside of the VOTABLE
class hierarchy.
get_XXX
and set_XXX
accessors for attributes
and elements are derived directly from the names of the attributes or
elements. Attribute and element names containing embedded hyphens
('-
') use accessors where the hyphen is mapped to an underscore
('_
') in the name of the accessor method. This is a necessity,
since the hyphen is not a valid name character in Perl.
VOTABLE::OPTION
object always has an underlying
XML::DOM::Element
object. As long as the internal structure is
manipulated only by the publicly-available methods, this should be an
adequate assumption. If a method detects an aberrant case, a warning
message is printed (using the Carp::carp
subroutine), and the
method fails.
XML::DOM
methods always
succeed. If a method detects an aberrant case, a warning message is
printed (using the Carp::carp
subroutine), and the method fails.
set_XXX
accessors do not perform validation of the
new attribute values. The exceptions are the accessors for attributes
with enumerated values; the new value is checked against the list of
acceptable values, as defined in the DTD.
VOTABLE
, VOTABLE::VALUES
Eric Winter, NASA GSFC (elwinter@milkyway.gsfc.nasa.gov)
$Id: OPTION.pm,v 1.1.1.8 2002/05/21 14:12:00 elwinter Exp $