1   /*
    2    * Copyright (c) 2004 World Wide Web Consortium,
    3    *
    4    * (Massachusetts Institute of Technology, European Research Consortium for
    5    * Informatics and Mathematics, Keio University). All Rights Reserved. This
    6    * work is distributed under the W3C(r) Software License [1] in the hope that
    7    * it will be useful, but WITHOUT ANY WARRANTY; without even the implied
    8    * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
    9    *
   10    * [1] http://www.w3.org/Consortium/Legal/2002/copyright-software-20021231
   11    */
   12   
   13   package org.w3c.dom.ls;
   14   
   15   /**
   16    *  <code>LSResourceResolver</code> provides a way for applications to 
   17    * redirect references to external resources. 
   18    * <p> Applications needing to implement custom handling for external 
   19    * resources can implement this interface and register their implementation 
   20    * by setting the "resource-resolver" parameter of 
   21    * <code>DOMConfiguration</code> objects attached to <code>LSParser</code> 
   22    * and <code>LSSerializer</code>. It can also be register on 
   23    * <code>DOMConfiguration</code> objects attached to <code>Document</code> 
   24    * if the "LS" feature is supported. 
   25    * <p> The <code>LSParser</code> will then allow the application to intercept 
   26    * any external entities, including the external DTD subset and external 
   27    * parameter entities, before including them. The top-level document entity 
   28    * is never passed to the <code>resolveResource</code> method. 
   29    * <p> Many DOM applications will not need to implement this interface, but it 
   30    * will be especially useful for applications that build XML documents from 
   31    * databases or other specialized input sources, or for applications that 
   32    * use URNs. 
   33    * <p ><b>Note:</b>  <code>LSResourceResolver</code> is based on the SAX2 [<a href='http://www.saxproject.org/'>SAX</a>] <code>EntityResolver</code> 
   34    * interface. 
   35    * <p>See also the <a href='http://www.w3.org/TR/2004/REC-DOM-Level-3-LS-20040407'>Document Object Model (DOM) Level 3 Load
   36   and Save Specification</a>.
   37    */
   38   public interface LSResourceResolver {
   39       /**
   40        *  Allow the application to resolve external resources. 
   41        * <br> The <code>LSParser</code> will call this method before opening any 
   42        * external resource, including the external DTD subset, external 
   43        * entities referenced within the DTD, and external entities referenced 
   44        * within the document element (however, the top-level document entity 
   45        * is not passed to this method). The application may then request that 
   46        * the <code>LSParser</code> resolve the external resource itself, that 
   47        * it use an alternative URI, or that it use an entirely different input 
   48        * source. 
   49        * <br> Application writers can use this method to redirect external 
   50        * system identifiers to secure and/or local URI, to look up public 
   51        * identifiers in a catalogue, or to read an entity from a database or 
   52        * other input source (including, for example, a dialog box). 
   53        * @param type  The type of the resource being resolved. For XML [<a href='http://www.w3.org/TR/2004/REC-xml-20040204'>XML 1.0</a>] resources 
   54        *   (i.e. entities), applications must use the value 
   55        *   <code>"http://www.w3.org/TR/REC-xml"</code>. For XML Schema [<a href='http://www.w3.org/TR/2001/REC-xmlschema-1-20010502/'>XML Schema Part 1</a>]
   56        *   , applications must use the value 
   57        *   <code>"http://www.w3.org/2001/XMLSchema"</code>. Other types of 
   58        *   resources are outside the scope of this specification and therefore 
   59        *   should recommend an absolute URI in order to use this method. 
   60        * @param namespaceURI  The namespace of the resource being resolved, 
   61        *   e.g. the target namespace of the XML Schema [<a href='http://www.w3.org/TR/2001/REC-xmlschema-1-20010502/'>XML Schema Part 1</a>]
   62        *    when resolving XML Schema resources. 
   63        * @param publicId  The public identifier of the external entity being 
   64        *   referenced, or <code>null</code> if no public identifier was 
   65        *   supplied or if the resource is not an entity. 
   66        * @param systemId  The system identifier, a URI reference [<a href='http://www.ietf.org/rfc/rfc2396.txt'>IETF RFC 2396</a>], of the 
   67        *   external resource being referenced, or <code>null</code> if no 
   68        *   system identifier was supplied. 
   69        * @param baseURI  The absolute base URI of the resource being parsed, or 
   70        *   <code>null</code> if there is no base URI. 
   71        * @return  A <code>LSInput</code> object describing the new input 
   72        *   source, or <code>null</code> to request that the parser open a 
   73        *   regular URI connection to the resource. 
   74        */
   75       public LSInput resolveResource(String type, 
   76                                      String namespaceURI, 
   77                                      String publicId, 
   78                                      String systemId, 
   79                                      String baseURI);
   80   
   81   }