operator
usemap (is | isnt) (#none | #empty)
usemap
is an element test, which tests the short reference map associated with the currently opened element (or the element specified by the element-qualifiers) for one of the map names specified in the test.
This test is used to detect the association of usemap
s with the elements in the DTD, not in the document instance.
The test succeeds:
#empty
short reference map is associated with the element and #empty
is specified.
#none
is specified.
Knowing whether or not an element type has an associated usemap
declaration is important if the OmniMark program is creating an SGML document from an input SGML document: usemap
may affect the way the short reference delimiters are interpreted. When "normalizing" a document, it is usually safest to issue a "<!USEMAP #EMPTY>" declaration at the start of any element with which a usemap
declaration (for a map other than #empty
) has been associated in the DTD.
The usemap-name is the name of a usemap
declaration in the DTD.
Elements which have had short reference maps associated with them by usemap
declarations can be identified by the usemap is
test. Short reference map names are subject to the NAMELEN
and NAMECASE GENERAL
declarations in the SGML declaration..
If the element-qualifier specifies an element which does not exist, then the test fails.
The following variations are permitted: