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 * 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
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package org.apache.xerces.impl.xs;

import org.apache.xerces.impl.xs.util.XSGrammarPool;
import org.apache.xerces.xni.grammars.Grammar;
import org.apache.xerces.xni.grammars.XMLGrammarDescription;
import org.apache.xerces.xni.grammars.XSGrammar;
import org.apache.xerces.xni.parser.XMLInputSource;
import org.apache.xerces.xs.LSInputList;
import org.apache.xerces.xs.StringList;
import org.apache.xerces.xs.XSConstants;
import org.apache.xerces.xs.XSLoader;
import org.apache.xerces.xs.XSModel;
import org.apache.xerces.xs.XSNamedMap;
import org.apache.xerces.xs.XSObjectList;
import org.apache.xerces.xs.XSTypeDefinition;
import org.w3c.dom.DOMConfiguration;
import org.w3c.dom.DOMException;
import org.w3c.dom.DOMStringList;
import org.w3c.dom.ls.LSInput;

An implementation of XSLoader which wraps XMLSchemaLoader.
Author:
Michael Glavassevich, IBM
@xerces.internal
Version:
$Id: XSLoaderImpl.java 699892 2008-09-28 21:08:27Z mrglavas $/**
 * <p>An implementation of XSLoader which wraps XMLSchemaLoader.</p>
 * 
 * @xerces.internal

 * 
 * @author Michael Glavassevich, IBM
 * 
 * @version $Id: XSLoaderImpl.java 699892 2008-09-28 21:08:27Z mrglavas $
 */
public final class XSLoaderImpl implements XSLoader, DOMConfiguration {
    
    
Grammar pool. Need this to prevent us from
getting two grammars from the same namespace.
/**
     * Grammar pool. Need this to prevent us from
     * getting two grammars from the same namespace.
     */
    private final XSGrammarPool fGrammarPool = new XSGrammarMerger();
    
    
Schema loader. /** Schema loader. **/
    private final XMLSchemaLoader fSchemaLoader = new XMLSchemaLoader();
    
    
No-args constructor.
/**
     * No-args constructor.
     */
    public XSLoaderImpl() {
        fSchemaLoader.setProperty(XMLSchemaLoader.XMLGRAMMAR_POOL, fGrammarPool);
    }

    
 The configuration of a document. It maintains a table of recognized 
parameters. Using the configuration, it is possible to change the 
behavior of the load methods. The configuration may support the 
setting of and the retrieval of the following non-boolean parameters 
defined on the DOMConfiguration interface: 
error-handler (DOMErrorHandler) and 
resource-resolver (LSResourceResolver). 

 The following list of boolean parameters is defined: 


"validate"


true
[required] (default) Validate an XML 
Schema during loading. If validation errors are found, the error 
handler is notified. 
false
[optional] Do not 
report errors during the loading of an XML Schema document. 


/**
     *  The configuration of a document. It maintains a table of recognized 
     * parameters. Using the configuration, it is possible to change the 
     * behavior of the load methods. The configuration may support the 
     * setting of and the retrieval of the following non-boolean parameters 
     * defined on the <code>DOMConfiguration</code> interface: 
     * <code>error-handler</code> (<code>DOMErrorHandler</code>) and 
     * <code>resource-resolver</code> (<code>LSResourceResolver</code>). 
     * <br> The following list of boolean parameters is defined: 
     * <dl>
     * <dt>
     * <code>"validate"</code></dt>
     * <dd>
     * <dl>
     * <dt><code>true</code></dt>
     * <dd>[required] (default) Validate an XML 
     * Schema during loading. If validation errors are found, the error 
     * handler is notified. </dd>
     * <dt><code>false</code></dt>
     * <dd>[optional] Do not 
     * report errors during the loading of an XML Schema document. </dd>
     * </dl></dd>
     * </dl>
     */
    public DOMConfiguration getConfig() {
        return this;
    }

    
Parses the content of XML Schema documents specified as the list of URI 
references. If the URI contains a fragment identifier, the behavior 
is not defined by this specification. 
Params:
uriList – The list of URI locations.
Returns:
An XSModel representing the schema documents./**
     * Parses the content of XML Schema documents specified as the list of URI 
     * references. If the URI contains a fragment identifier, the behavior 
     * is not defined by this specification. 
     * @param uriList The list of URI locations.
     * @return An XSModel representing the schema documents.
     */
    public XSModel loadURIList(StringList uriList) {
        int length = uriList.getLength();
        try {
            fGrammarPool.clear();
            for (int i = 0; i < length; ++i) {
                fSchemaLoader.loadGrammar(new XMLInputSource(null, uriList.item(i), null));
            }
            return fGrammarPool.toXSModel();
        } 
        catch (Exception e) {
            fSchemaLoader.reportDOMFatalError(e);
            return null;
        }
    }

    
 Parses the content of XML Schema documents specified as a list of 
LSInputs. 
Params:
is –  The list of LSInputs from which the XML 
  Schema documents are to be read.
Returns:
An XSModel representing the schema documents./**
     *  Parses the content of XML Schema documents specified as a list of 
     * <code>LSInput</code>s. 
     * @param is  The list of <code>LSInput</code>s from which the XML 
     *   Schema documents are to be read. 
     * @return An XSModel representing the schema documents.
     */
    public XSModel loadInputList(LSInputList is) {
        final int length = is.getLength();
        try {
            fGrammarPool.clear();
            for (int i = 0; i < length; ++i) {
                fSchemaLoader.loadGrammar(fSchemaLoader.dom2xmlInputSource(is.item(i)));
            }
            return fGrammarPool.toXSModel();
        } 
        catch (Exception e) {
            fSchemaLoader.reportDOMFatalError(e);
            return null;
        }
    }

    
Parse an XML Schema document from a location identified by a URI 
reference. If the URI contains a fragment identifier, the behavior is 
not defined by this specification. 
Params:
uri – The location of the XML Schema document to be read.
Returns:
An XSModel representing this schema./**
     * Parse an XML Schema document from a location identified by a URI 
     * reference. If the URI contains a fragment identifier, the behavior is 
     * not defined by this specification. 
     * @param uri The location of the XML Schema document to be read.
     * @return An XSModel representing this schema.
     */
    public XSModel loadURI(String uri) {
        try {
            fGrammarPool.clear();
            return ((XSGrammar) fSchemaLoader.loadGrammar(new XMLInputSource(null, uri, null))).toXSModel();
        }
        catch (Exception e){
            fSchemaLoader.reportDOMFatalError(e);
            return null;
        }
    }

    
 Parse an XML Schema document from a resource identified by a 
LSInput . 
Params:
is –  The LSInput from which the source 
  document is to be read.
Returns:
An XSModel representing this schema./**
     *  Parse an XML Schema document from a resource identified by a 
     * <code>LSInput</code> . 
     * @param is  The <code>LSInput</code> from which the source 
     *   document is to be read. 
     * @return An XSModel representing this schema.
     */
    public XSModel load(LSInput is) {
        try {
            fGrammarPool.clear();
            return ((XSGrammar) fSchemaLoader.loadGrammar(fSchemaLoader.dom2xmlInputSource(is))).toXSModel();
        } 
        catch (Exception e) {
            fSchemaLoader.reportDOMFatalError(e);
            return null;
        }
    }

    /* (non-Javadoc)
     * @see org.apache.xerces.dom3.DOMConfiguration#setParameter(java.lang.String, java.lang.Object)
     */
    public void setParameter(String name, Object value) throws DOMException {
        fSchemaLoader.setParameter(name, value);
    }

    /* (non-Javadoc)
     * @see org.apache.xerces.dom3.DOMConfiguration#getParameter(java.lang.String)
     */
    public Object getParameter(String name) throws DOMException {
        return fSchemaLoader.getParameter(name);
    }

    /* (non-Javadoc)
     * @see org.apache.xerces.dom3.DOMConfiguration#canSetParameter(java.lang.String, java.lang.Object)
     */
    public boolean canSetParameter(String name, Object value) {
        return fSchemaLoader.canSetParameter(name, value);
    }

    /* (non-Javadoc)
     * @see org.apache.xerces.dom3.DOMConfiguration#getParameterNames()
     */
    public DOMStringList getParameterNames() {
        return fSchemaLoader.getParameterNames();
    }
    
    
Grammar pool which merges grammars from the same namespace into one. This eliminates
duplicate named components. It doesn't ensure that the grammar is consistent, however
this no worse than than the behaviour of XMLSchemaLoader alone when used as an XSLoader.
/** 
     * Grammar pool which merges grammars from the same namespace into one. This eliminates
     * duplicate named components. It doesn't ensure that the grammar is consistent, however
     * this no worse than than the behaviour of XMLSchemaLoader alone when used as an XSLoader.
     */
    private static final class XSGrammarMerger extends XSGrammarPool {
        
        public XSGrammarMerger () {}
        
        public void putGrammar(Grammar grammar) {
            SchemaGrammar cachedGrammar = 
                toSchemaGrammar(super.getGrammar(grammar.getGrammarDescription()));
            if (cachedGrammar != null) {
                SchemaGrammar newGrammar = toSchemaGrammar(grammar);
                if (newGrammar != null) {
                    mergeSchemaGrammars(cachedGrammar, newGrammar);
                }
            }
            else {
                super.putGrammar(grammar);
            }
        }
        
        private SchemaGrammar toSchemaGrammar (Grammar grammar) {
            return (grammar instanceof SchemaGrammar) ? (SchemaGrammar) grammar : null;
        }
        
        private void mergeSchemaGrammars(SchemaGrammar cachedGrammar, SchemaGrammar newGrammar) {

            /** Add new top-level element declarations. **/
            XSNamedMap map = newGrammar.getComponents(XSConstants.ELEMENT_DECLARATION);
            int length = map.getLength();
            for (int i = 0; i < length; ++i) {
                XSElementDecl decl = (XSElementDecl) map.item(i);
                if (cachedGrammar.getGlobalElementDecl(decl.getName()) == null) {
                    cachedGrammar.addGlobalElementDecl(decl);
                }
            }
            
            /** Add new top-level attribute declarations. **/
            map = newGrammar.getComponents(XSConstants.ATTRIBUTE_DECLARATION);
            length = map.getLength();
            for (int i = 0; i < length; ++i) {
                XSAttributeDecl decl = (XSAttributeDecl) map.item(i);
                if (cachedGrammar.getGlobalAttributeDecl(decl.getName()) == null) {
                    cachedGrammar.addGlobalAttributeDecl(decl);
                }
            }
            
            /** Add new top-level type definitions. **/
            map = newGrammar.getComponents(XSConstants.TYPE_DEFINITION);
            length = map.getLength();
            for (int i = 0; i < length; ++i) {
                XSTypeDefinition decl = (XSTypeDefinition) map.item(i);
                if (cachedGrammar.getGlobalTypeDecl(decl.getName()) == null) {
                    cachedGrammar.addGlobalTypeDecl(decl);
                }
            }
            
            /** Add new top-level attribute group definitions. **/
            map = newGrammar.getComponents(XSConstants.ATTRIBUTE_GROUP);
            length = map.getLength();
            for (int i = 0; i < length; ++i) {
                XSAttributeGroupDecl decl = (XSAttributeGroupDecl) map.item(i);
                if (cachedGrammar.getGlobalAttributeGroupDecl(decl.getName()) == null) {
                    cachedGrammar.addGlobalAttributeGroupDecl(decl);
                }
            }
            
            /** Add new top-level model group definitions. **/
            map = newGrammar.getComponents(XSConstants.MODEL_GROUP);
            length = map.getLength();
            for (int i = 0; i < length; ++i) {
                XSGroupDecl decl = (XSGroupDecl) map.item(i);
                if (cachedGrammar.getGlobalGroupDecl(decl.getName()) == null) {
                    cachedGrammar.addGlobalGroupDecl(decl);
                }
            }
            
            /** Add new top-level notation declarations. **/
            map = newGrammar.getComponents(XSConstants.NOTATION_DECLARATION);
            length = map.getLength();
            for (int i = 0; i < length; ++i) {
                XSNotationDecl decl = (XSNotationDecl) map.item(i);
                if (cachedGrammar.getGlobalNotationDecl(decl.getName()) == null) {
                    cachedGrammar.addGlobalNotationDecl(decl);
                }
            }
            
            /** 
             * Add all annotations. Since these components are not named it's
             * possible we'll add duplicate components. There isn't much we can
             * do. It's no worse than XMLSchemaLoader when used as an XSLoader.
             */
            XSObjectList annotations = newGrammar.getAnnotations();
            length = annotations.getLength();
            for (int i = 0; i < length; ++i) {
                cachedGrammar.addAnnotation((XSAnnotationImpl) annotations.item(i));
            }
            
        }
        
        public boolean containsGrammar(XMLGrammarDescription desc) {
            return false;
        }
        
        public Grammar getGrammar(XMLGrammarDescription desc) {
            return null;
        }
        
        public Grammar retrieveGrammar(XMLGrammarDescription desc) {
            return null;
        }
        
        public Grammar [] retrieveInitialGrammarSet (String grammarType) {
            return new Grammar[0];
        }
    }
}