• NAME
• SYNOPSIS
• DESCRIPTION
• Methods
• new($str_or_ref, %options)
• get_ID
• set_ID($id)
• get_name
• set_name($name)
• get_value
• set_value($value)
• get
• set($str)
• Notes on class internals
• WARNINGS
• SEE ALSO
• AUTHOR
• VERSION

NAME

VOTABLE::INFO - VOTABLE INFO XML element class

SYNOPSIS

use VOTABLE::INFO;

DESCRIPTION

This class implements the INFO element from the VOTABLE DTD. This element is used to store arbitrary NAME=VALUE and text data that does not fit into any other element.

The INFO element is a Tier 0 element, and is described by the following excerpt from the VOTABLE 1.0 DTD:

 <!ELEMENT INFO (#PCDATA)>
 <!ATTLIST INFO
         ID ID #IMPLIED
         name CDATA #IMPLIED
         value CDATA #IMPLIED
 >

Methods

new($str_or_ref, %options)

Create a new VOTABLE::INFO object, and return a reference to it. If the first argument ($str_or_ref) is a string, it is used as the initial PCDATA content of the INFO element. If the first argument is a reference to a XML::DOM::Element object, that object is used to initialize the new INFO element (implicitly assuming that the XML::DOM::Element object contains a valid INFO element). The %options hash is used to set the attributes of the new element. If the first argument is missing or undefined, or an empty string, create and return an empty VOTABLE::INFO object. Return undef if an error occurs.

get_ID

Return the value of the ID attribute. Return undef if the attribute has not been set, or an error occurs.

set_ID($id)

Set the value of the ID attribute to the specified value. Return the new value of the attribute on success, or 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 on success, or undef if an error occurs.

get

Return a string containing the PCDATA content of the INFO element. Return undef if the element has no PCDATA content, or an error occurs.

set($str)

Set the PCDATA content of the INFO element to the specified string. Return the string on success, or undef 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::COOSYS 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::Document, VOTABLE::RESOURCE

AUTHOR

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

VERSION

$Id: INFO.pm,v 1.1.1.9 2002/05/21 14:11:04 elwinter Exp $