An object that implements this interface that can be called by the processor to turn a URI used in document(), xsl:import, or xsl:include into a Source object.

Called by the processor when it encounters an xsl:include, xsl:import, or document() function.
Parameters
hrefAn href attribute, which may be relative or absolute.
baseThe base URI against which the first argument will be made absolute if the absolute URI is required.
Return
A Source object, or null if the href cannot be resolved, and the processor should try to resolve the URI itself.
Throws
TransformerExceptionif an error occurs when trying to resolve the URI.