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////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Copyright (c) 2013 Saxonica Limited.
// This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0.
// If a copy of the MPL was not distributed with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
// This Source Code Form is "Incompatible With Secondary Licenses", as defined by the Mozilla Public License, v. 2.0.
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
package net.sf.saxon.lib;
import javax.xml.transform.Source;
import javax.xml.transform.TransformerException;
import javax.xml.transform.URIResolver;
/**
* The standard JAXP URIResolver is given a relative URI and a base URI and returns the resource
* identified by this combination. However, to support a stable implementation of the doc() function,
* Saxon needs to know what the absolute URI is before the resource is fetched, so it can determine whether
* a document with that absolute URI actually exists.
*
* This extended interface defines a URIResolver that separates the two functions of resolving a relative URI
* against a base URI, and fetching a resource with that absolute URI. If the URI resolver supplied to Saxon
* implements this interface, the absolute URI associated with a loaded document will be the URI returned by
* this resolver.
*
* The particular motivation for providing this interface is to allow a URIResolver to wrap a .NET XmlResolver,
* which has additional capability not present in the JAXP interface.
*/
public interface RelativeURIResolver extends URIResolver {
/**
* Create an absolute URI from a relative URI and a base URI. This method performs the
* process which is correctly called "URI resolution": this is purely a syntactic operation
* on the URI strings, and does not retrieve any resources.
* @param href A relative or absolute URI, to be resolved against the specified base URI
* @param base The base URI against which the first argument will be made
* absolute if the absolute URI is required.
* @return A string containing the absolute URI that results from URI resolution. If the resource
* needs to be fetched, this absolute URI will be supplied as the href parameter in a subsequent
* call to the resolve method.
* @throws javax.xml.transform.TransformerException if any failure occurs
*/
public String makeAbsolute(String href, String base)
throws TransformerException;
/**
* Called by the processor when it encounters
* an xsl:include, xsl:import, or document() function.
*
* @param uri The absolute URI to be dereferenced
*
* @return A Source object, or null if the href cannot be dereferenced,
* and the processor should try to resolve the URI itself.
*
* @throws javax.xml.transform.TransformerException if an error occurs when trying to
* resolve the URI.
*/
public Source dereference(String uri)
throws TransformerException;
/**
* Called by the processor when it encounters
* an xsl:include, xsl:import, or document() function.
*
*
Despite the name, the main purpose of this method is to dereference the URI, not merely
* to resolve it.
*
* This method is provided because it is required by the interface. When using a RelativeURIResolver,
* the single-argument dereference() method is preferred. The result of calling this method should be the
* same as the result of calling dereference(makeAbsolute(href, base))
*
* @param href An href attribute, which may be relative or absolute.
* @param base The 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 javax.xml.transform.TransformerException if an error occurs when trying to
* resolve the URI.
*/
public Source resolve(String href, String base)
throws TransformerException;
/**
* Specify the media type of the resource that is expected to be delivered. This information is
* supplied by the processor primarily to indicate whether the URIResolver is allowed to return
* an XML tree already parsed. If the value is "text/plain" then the Source returned by the
* resolve() method should be a StreamSource.
* @param mediaType the expected media type
*/
public void setExpectedMediaType(String mediaType);
// TODO: method is not currently used
}