txmlcatalog

Associates an XML stream with a catalog file. The macro will attach the location of the catalog file to the stream so that the LibXML parser can access it during parsing. Only one catalog file can be used per stream. If no catalog file is available, LibXML will first check the contents of the variable ^_cl_xmlcatalog to see if this contains a path to a valid catalog file, otherwise it will attempt to use normal relative path resolution to try and work out which file it needs to access to find the correct DTD or entity declaration.

[no parameter]	Invoke the Define XML Catalog URI dialog box.
cat	The name of the catalog file
URI	The URI of the catalog file

XML catalogs provide a mechanism for mapping from a unique identifier to a URI reference and are used primarily to access DTDs and entity declarations.

For example, if the DOCTYPE declaration in an XML document contains the following <!DOCTYPE root PUBLIC "ISO 8879:1986//ENTITIES Added Latin 1//EN" "iso-lat1.xml">, the LibXML parser will be able to inspect the catalog file associated with the XML document and look up the entry matching the Public Identifier defined in the declaration to get the URI containing the required entities.