Working with XML Catalogs

When Internet access is not available or the Internet connection is slow the OASIS XML catalogs present in the list maintained in the XML Catalog Preferences panel will be scanned trying to map a remote system ID (at document validation) or a URI reference (at document transformation) pointing to a resource on a remote Web server to a local copy of the same resource. If a match is found then Oxygen XML Developer plugin will use the local copy of the resource instead of the remote one. This enables the XML author to work on his/hers XML project without Internet access or when the connection is slow and waiting until the remote resource is accessed and fetched becomes unacceptable. Also XML catalogs make documents machine independent so that they can be shared by many developers by modifying only the XML catalog mappings related to the shared documents.

Oxygen XML Developer plugin supports any XML catalog file that conforms to one of:

The version 1.1 of the OASIS XML Catalog specification introduces the possibility to map a system ID, a public ID or a URI to a local copy using only a suffix of the ID or URI used in the actual document. This is done using the new catalog elements systemSuffix and uriSuffix.

An XML catalog can be used also to map a W3C XML Schema specified with an URN in the xsi:schemaLocation attribute of an XML document to a local copy of the schema. For example if the XML document specifies the schema with:

<topic xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
                    xsi:noNamespaceSchemaLocation="urn:oasis:names:tc:dita:xsd:topic.xsd:1.1">

Inside an XML Schema if an xs:import statement specifies only the namespace attribute, without the schemaLocation attribute, Oxygen XML Developer plugin will try to resolve the specified namespace URI through one of the XML catalogs configured in Preferences pages.

The URN can be resolved to a local schema file with a catalog entry like:

<system systemId="urn:oasis:names:tc:dita:xsd:topic.xsd:1.1"
    uri="topic.xsd"/>

An XML Catalog file can be created quickly in Oxygen XML Developer plugin starting from the two XML Catalog document templates called OASIS XML Catalog 1.0 and OASIS XML Catalog 1.1 and available in the document templates dialog.

User preferences related to XML Catalogs can be configured from Window > Preferences ... > oXygen > XML > XML Catalog