#ifndef DOMEntityResolver_HEADER_GUARD_

#define DOMEntityResolver_HEADER_GUARD_

/*

 * Licensed to the Apache Software Foundation (ASF) under one or more

 * contributor license agreements.  See the NOTICE file distributed with

 * this work for additional information regarding copyright ownership.

 * The ASF licenses this file to You under the Apache License, Version 2.0

 * (the "License"); you may not use this file except in compliance with

 * the License.  You may obtain a copy of the License at

 * 

 *      http://www.apache.org/licenses/LICENSE-2.0

 * 

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

/*

 * $Id: DOMEntityResolver.hpp 568078 2007-08-21 11:43:25Z amassari $

 */

#include <xercesc/util/XercesDefs.hpp>

XERCES_CPP_NAMESPACE_BEGIN

class DOMInputSource;

/**

  * DOMEntityResolver provides a way for applications to redirect references

  * to external entities.

  *

  * <p>Applications needing to implement customized handling for external

  * entities must implement this interface and register their implementation

  * by setting the entityResolver attribute of the DOMBuilder.</p>

  *

  * <p>The DOMBuilder will then allow the application to intercept any

  * external entities (including the external DTD subset and external parameter

  * entities) before including them.</p>

  *

  * <p>Many DOM applications will not need to implement this interface, but it

  * will be especially useful for applications that build XML documents from

  * databases or other specialized input sources, or for applications that use

  * URNs.</p>

  *

  * @see DOMBuilder#setEntityResolver

  * @see DOMInputSource#DOMInputSource

  * @since DOM Level 3

  */

class CDOM_EXPORT DOMEntityResolver

{

protected:

    // -----------------------------------------------------------------------

    //  Hidden constructors

    // -----------------------------------------------------------------------

    /** @name Hidden constructors */

    //@{    

    DOMEntityResolver() {};

    //@}

private:

    // -----------------------------------------------------------------------

    // Unimplemented constructors and operators

    // -----------------------------------------------------------------------

    /** @name Unimplemented constructors and operators */

    //@{

    DOMEntityResolver(const DOMEntityResolver &);

    DOMEntityResolver & operator = (const DOMEntityResolver &);

    //@}

public:

    // -----------------------------------------------------------------------

    //  All constructors are hidden, just the destructor is available

    // -----------------------------------------------------------------------

    /** @name Destructor */

    //@{

    /**

     * Destructor

     *

     */

    virtual ~DOMEntityResolver() {};

    //@}

    // -----------------------------------------------------------------------

    //  Virtual DOMEntityResolver interface

    // -----------------------------------------------------------------------

    /** @name Functions introduced in DOM Level 2 */

    //@{

    /**

     * Allow the application to resolve external entities.

     *

     * <p>The DOMBuilder will call this method before opening any external

     * entity except the top-level document entity (including the

     * external DTD subset, external entities referenced within the

     * DTD, and external entities referenced within the document

     * element): the application may request that the DOMBuilder resolve

     * the entity itself, that it use an alternative URI, or that it

     * use an entirely different input source.</p>

     *

     * <p>Application writers can use this method to redirect external

     * system identifiers to secure and/or local URIs, to look up

     * public identifiers in a catalogue, or to read an entity from a

     * database or other input source (including, for example, a dialog

     * box).</p>

     *

     * <p>If the system identifier is a URL, the DOMBuilder parser must

     * resolve it fully before reporting it to the application.</p>

     *

     * <p> The returned DOMInputSource is owned by the DOMBuilder which is

     *     responsible to clean up the memory.

     *

     * <p><b>"Experimental - subject to change"</b></p>

     *

     * @param publicId The public identifier of the external entity

     *        being referenced, or null if none was supplied.

     * @param systemId The system identifier of the external entity

     *        being referenced.

     * @param baseURI The absolute base URI of the resource being parsed, or

     *        <code>null</code> if there is no base URI.

     * @return A DOMInputSource object describing the new input source,

     *         or <code>null</code> to request that the parser open a regular

     *         URI connection to the system identifier.

     *         The returned DOMInputSource is owned by the DOMBuilder which is

     *         responsible to clean up the memory.

     * @see DOMInputSource#DOMInputSource

     * @since DOM Level 3

     */

    virtual DOMInputSource* resolveEntity

    (

        const   XMLCh* const    publicId

        , const XMLCh* const    systemId

        , const XMLCh* const    baseURI

    ) = 0;

    //@}

};

XERCES_CPP_NAMESPACE_END

#endif