Configuring XML Catalogs
In the XML sample file for SDF you did not use a
               xsi:schemaLocation attribute, but instead you let the editor use the
               schema from the association. However, there are cases in which you must reference
               the
               location of a schema file from a remote web location and an Internet connection may
               not be
               available. In such cases an XML catalog may be used to map the web location to a local
               file
               system entry. The following procedure presents an example of using an XML catalogs,
               by
               modifying our sdf.xsd XML Schema file from the Example Files Listings.
            
- Create a catalog file that will help the parser locate the schema for validating the
                  XML document. The file must map the location of the schema to a local version of the
                  schema.Create a new XML file called catalog.xmland save it into the[OXYGEN_INSTALL_DIR]/frameworks/sdfdirectory. The content of the file should be:<?xml version="1.0"?> <catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"> <uri name="http://www.oxygenxml.com/SDF/abs.xsd" uri="schema/abs.xsd"/> <uri name="http://www.oxygenxml.com/SDF/abs.xsd" uri="schema/abs.xsd"/> </catalog>
- Add catalog files to your Document Type Association using the Catalogs tab from the Document Type configuration dialog box.
To test the catalog settings, restart Oxygen XML Editor and try to validate a new sample custom framework document. There should be no errors.
The sdf.xsd schema that validates the document refers the other file
               abs.xsd through an import element:
            
<xs:import namespace= "http://www.oxygenxml.com/sample/documentation/abstracts" schemaLocation="http://www.oxygenxml.com/SDF/abs.xsd"/>
The schemaLocation attribute references the abs.xsd
               file:
            
xsi:schemaLocation="http://www.oxygenxml.com/sample/documentation/abstracts"
    http://www.oxygenxml.com/SDF/abs.xsd"/>
            The catalog mapping is:
http://www.oxygenxml.com/SDF/abs.xsd -> schema/abs.xsd
This means that all the references to http://www.oxygenxml.com/SDF/abs.xsd must be
               resolved to the abs.xsd file located in the schema
               directory. The URI element is used by URI resolvers (for example, to resolve a URI
               reference
               used in an XSLT stylesheet).
            
