XML documents often rely on Document Type Definitions (DTD). While parsing a document with BaseX elements and entities can be checked for validity with respect to that particular DTD.
XHTML for example defines its doctype via the following line:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
xhtml1-strict.dtd obviously involves some network traffic. When dealing with single files this may seem tolerable, but
importing large collections might benefit from caching these resources locally. Depending on your connection you will experience significant improvements.
XML Entity and URI Resolvers in BaseX
BaseX is able to use available URI resolvers without any additional configuration.
To enable entity resolving you have to provide a valid XML Catalog file. A simple working example for XHTML might look like this:
<?xml version="1.0"?> <catalog prefer="system" xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"> <rewriteSystem systemIdStartString="http://www.w3.org/TR/xhtml1/DTD/" rewritePrefix="file:///path/to/dtds/" /> </catalog>
This rewrites all SystemIds starting with: http://www.w3.org/TR/xhtml1/DTD/ to file:///path/to/dtds/.
The XHTML DTD
xhtml1-strict.dtd and all its linked resources will now be loaded from the specified path.
When running BaseX in GUI mode simply provide the path to your XML Catalog file in the Parsing-Tab of the Database Creation Dialog.
Console & Server Mode
To enable Entity Resolving in Console Mode specify the following options:
SET CATFILE [path]
Now entity resolving is active for the current session. All subsequent
ADD commands will use the catalog file to resolve entities.
Please note that entity resolving only works with option:
SET INTPARSE false.
INTPARSE is set to false by default.
Using other Resolvers
There might be some cases when you do not want to use the built-in resolver that Java provides by default (via
java -cp basex.jar:resolver.jar org.basex.BaseXServer