new($str_or_ref, %options)
get_ID
set_ID($id)
get_action
set_action($action)
get_content_role
set_content_role($content_role)
get_content_type
set_content_type($content_type)
get_gref
set_gref($gref)
get_href
set_href($href)
get_title
set_title($title)
get_value
set_value($value)
get
set($str)
VOTABLE::LINK - VOTABLE LINK XML element class
use VOTABLE::LINK;
This class implements the LINK
element from the VOTABLE
DTD. This element is used to store traditional HTTP
hyperlinks to
supporting information (using the href
attribute), or a more
general-purpose link (using the gref
attribute).
The LINK element is a Tier 0 element, and is described by the
following excerpt from the VOTABLE
1.0 DTD:
<!ELEMENT LINK (#PCDATA)> <!ATTLIST LINK ID ID #IMPLIED content-role (query | hints | doc) #IMPLIED content-type CDATA #IMPLIED title CDATA #IMPLIED value CDATA #IMPLIED href CDATA #IMPLIED gref CDATA #IMPLIED action CDATA #IMPLIED >
new($str_or_ref, %options)
Create a new VOTABLE::LINK
object, and return a reference to it. If
the first argument ($str_or_ref
) is a string, it is used as the
initial PCDATA
content of the LINK
element. If the first
argument is a reference to a XML::DOM::Element
object, that object
is used to initialize the new LINK
element (implicitly assuming
that the XML::DOM::Element
object contains a valid LINK
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::LINK
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($id)
Set the value of the ID
attribute to the specified value. Return
the new value of the attribute on success, or undef
if an error
occurs.
get_action
Return the value of the action
attribute. Return undef
if the
attribute has not been set, or an error occurs.
set_action($action)
Set the value of the action
attribute to the specified
value. Return the new value of the attribute on success, or undef
if an error occurs.
get_content_role
Return the value of the content-role attribute
. Return undef
if
the attribute has not been set, or an error occurs.
set_content_role($content_role)
Set the value of the content-role
attribute to the specified
value. Return the new value of the attribute on success, or undef
if an error occurs.
get_content_type
Return the value of the content-type
attribute. Return undef
if
the attribute has not been set, or an error occurs.
set_content_type($content_type)
Set the value of the content-type
attribute to the specified
value. Return the new value of the attribute on success, or undef
if an error occurs.
get_gref
Return the value of the gref
attribute. Return undef
if the
attribute has not been set, or an error occurs.
set_gref($gref)
Set the value of the gref
attribute to the specified value. Return
the new value of the attribute on success, or undef
if an error
occurs.
get_href
Return the value of the href
attribute. Return undef
if the
attribute has not been set, or an error occurs.
set_href($href)
Set the value of the href
attribute to the specified value. Return
the new value of the attribute on success, or undef
if an error
occurs.
get_title
Return the value of the title
attribute. Return undef
if the
attribute has not been set, or an error occurs.
set_title($title)
Set the value of the title
attribute to the specified value. Return
the new value of the attribute on success, or undef
if an error
occurs.
get_value
Return the value of the value
attribute. Return undef
if the
attribute has not been set, or an error occurs.
set_value($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.
get
Return a string containing the PCDATA
content of the LINK
element. Return undef
if the element has no PCDATA
content, or
an error occurs.
set($str)
Set the PCDATA
content of the LINK
element to the specified
string. Return the string 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::LINK
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::FIELD
, VOTABLE::PARAM
,
VOTABLE::RESOURCE
, VOTABLE::TABLE
Eric Winter, NASA GSFC (elwinter@milkyway.gsfc.nasa.gov)
$Id: LINK.pm,v 1.1.1.7 2002/05/21 14:11:17 elwinter Exp $