• NAME
• SYNOPSIS
• DESCRIPTION
• Methods
• new($xmldom_element, %options)
• get_td
• set_td(@votable_td)
• Notes on class internals
• WARNINGS
• SEE ALSO
• AUTHOR
• VERSION

NAME

VOTABLE::TR - VOTABLE TR XML element class

SYNOPSIS

use VOTABLE::TR;

DESCRIPTION

This class implements the TR element from the VOTABLE DTD. This element is used to store a single row in a data table.

The TR element is a Tier 1 element, and is described by the following excerpt from the VOTABLE 1.0 DTD:

 <!ELEMENT TR (TD+)>

Methods

new($xmldom_element, %options)

Create and return a new VOTABLE::TR 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::TR object. Return undef if an error occurs.

get_td

Return a list of the VOTABLE::TD objects for the TD elements which are the children of this TR element. Return an empty list if no TD elements are found, or if an error occurs.

set_td(@votable_td)

Set the TD elements for this TR element using the supplied list of VOTABLE::TD objects. Any previously existing TD elements are first removed. Return the input list on success, or an empty list if an error occurs.

Notes on class internals

• Method names that begin with a leading underscore ('_') are for internal use only, and should not be used outside of the VOTABLE class hierarchy.

• The names of the 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.

WARNINGS

• This code (perhaps unwisely) assumes that object internal structure is always maintained. For example, this code assumes that every VOTABLE::TR 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.

• Similarly, this code assumes that 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.

• Most attribute 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.

SEE ALSO

VOTABLE, VOTABLE::TABLEDATA, VOTABLE::TD

AUTHOR

Eric Winter, NASA GSFC (elwinter@milkyway.gsfc.nasa.gov)

VERSION

$Id: TR.pm,v 1.1.1.10 2002/05/21 14:14:07 elwinter Exp $