XML Catalog
XML Catalogs is a technique for replacement of external references in XML documents. This is checked when parsing the XML, if there is a substitution rule for the referenced external file in the catalog. Here is a matching rule is found, the existing in the file reference is replaced by the reference from the catalog. The catalog itself is an XML file that needs to be made known to the parser. XML Catalogs is an OASIS standard.
XML Catalogs has two primary applications:
Examples
The following example shows a catalog (usually stored in a file called catalog.xml ), the http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict for the external reference with the system identifier. dtd a local DTD provides under dtd/xhtml1/xhtml1-strict.dtd. Similar procedure is followed with the two other DTDs.
xml version = " 1.0"? >
xml version = " 1.0"? >
xml version = " 1.0"? >
< DOCTYPE catalog PUBLIC "- / / OASIS / / DTD Entity Resolution XML Catalog V1.1 / / EN " " http://www.oasis-open.org/committees/entity/release/1.1/catalog.dtd " >