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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
 * limitations under the License.
 */

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

import org.apache.xerces.impl.xpath.XPathException;
import org.apache.xerces.util.SymbolTable;
import org.apache.xerces.util.XMLChar;
import org.apache.xerces.xni.NamespaceContext;
import org.apache.xerces.xni.QName;
import org.apache.xerces.xni.XMLAttributes;
import org.apache.xerces.xs.ShortList;
import org.apache.xerces.xs.XSTypeDefinition;

Schema identity constraint selector.
Author:
Andy Clark, IBM
@xerces.internal
Version:
$Id: Selector.java 572110 2007-09-02 19:04:44Z mrglavas $/**
 * Schema identity constraint selector.
 *
 * @xerces.internal 
 *
 * @author Andy Clark, IBM
 * @version $Id: Selector.java 572110 2007-09-02 19:04:44Z mrglavas $
 */
public class Selector {

    //
    // Data
    //

    
XPath. /** XPath. */
    protected final Selector.XPath fXPath;

    
Identity constraint. /** Identity constraint. */
    protected final IdentityConstraint fIdentityConstraint;

    // the Identity constraint we're the matcher for.  Only
    // used for selectors!
    protected IdentityConstraint fIDConstraint;

    //
    // Constructors
    //

    
Constructs a selector. /** Constructs a selector. */
    public Selector(Selector.XPath xpath, 
                    IdentityConstraint identityConstraint) {
        fXPath = xpath;
        fIdentityConstraint = identityConstraint;
    } // <init>(Selector.XPath,IdentityConstraint)

    //
    // Public methods
    //

    
Returns the selector XPath. /** Returns the selector XPath. */
    public org.apache.xerces.impl.xpath.XPath getXPath() {
        return fXPath;
    } // getXPath():org.apache.xerces.v1.schema.identity.XPath

    
Returns the identity constraint. /** Returns the identity constraint. */
    public IdentityConstraint getIDConstraint() {
        return fIdentityConstraint;
    } // getIDConstraint():IdentityConstraint

    // factory method

    
Creates a selector matcher. 
Params:
activator –     The activator for this selector's fields.
initialDepth –  The depth in the document at which this matcher began its life;
                         used in correctly handling recursive elements./** Creates a selector matcher. 
     * @param activator     The activator for this selector's fields.
     * @param initialDepth  The depth in the document at which this matcher began its life;
     *                          used in correctly handling recursive elements.
     */
    public XPathMatcher createMatcher(FieldActivator activator, int initialDepth) {
        return new Selector.Matcher(fXPath, activator, initialDepth);
    } // createMatcher(FieldActivator):XPathMatcher

    //
    // Object methods
    //

    
Returns a string representation of this object. /** Returns a string representation of this object. */
    public String toString() {
        return fXPath.toString();
    } // toString():String

    //
    // Classes
    //

    
Schema identity constraint selector XPath expression.
Author:
Andy Clark, IBM
Version:
$Id: Selector.java 572110 2007-09-02 19:04:44Z mrglavas $/**
     * Schema identity constraint selector XPath expression.
     *
     * @author Andy Clark, IBM
     * @version $Id: Selector.java 572110 2007-09-02 19:04:44Z mrglavas $
     */
    public static class XPath
    extends org.apache.xerces.impl.xpath.XPath {

        //
        // Constructors
        //

        
Constructs a selector XPath expression. /** Constructs a selector XPath expression. */
        public XPath(String xpath, SymbolTable symbolTable, 
                     NamespaceContext context) throws XPathException {
            super(normalize(xpath), symbolTable, context);
            // verify that an attribute is not selected
            for (int i=0;i<fLocationPaths.length;i++) {
                org.apache.xerces.impl.xpath.XPath.Axis axis =
                fLocationPaths[i].steps[fLocationPaths[i].steps.length-1].axis;
                if (axis.type == XPath.Axis.ATTRIBUTE) {
                    throw new XPathException("c-selector-xpath");
                }
            }

        } // <init>(String,SymbolTable,NamespacesScope)

        private static String normalize(String xpath) {
            // NOTE: We have to prefix the selector XPath with "./" in
            //       order to handle selectors such as "." that select
            //       the element container because the fields could be
            //       relative to that element. -Ac
            //       Unless xpath starts with a descendant node -Achille Fokoue
            //      ... or a '.' or a '/' - NG
            //  And we also need to prefix exprs to the right of | with ./ - NG
            StringBuffer modifiedXPath = new StringBuffer(xpath.length()+5);
            int unionIndex = -1;
            do {
                if(!(XMLChar.trim(xpath).startsWith("/") || XMLChar.trim(xpath).startsWith("."))) {
                    modifiedXPath.append("./"); 
                }
                unionIndex = xpath.indexOf('|');
                if(unionIndex == -1) {
                    modifiedXPath.append(xpath);
                    break;
                }
                modifiedXPath.append(xpath.substring(0,unionIndex+1));
                xpath = xpath.substring(unionIndex+1, xpath.length());
            } while(true);
            return modifiedXPath.toString();
        }

    } // class Selector.XPath

    
Selector matcher.
Author:
Andy Clark, IBM/**
     * Selector matcher.
     *
     * @author Andy Clark, IBM
     */
    public class Matcher
    extends XPathMatcher {

        //
        // Data
        //

        
Field activator. /** Field activator. */
        protected final FieldActivator fFieldActivator;

        
Initial depth in the document at which this matcher was created. /** Initial depth in the document at which this matcher was created. */
        protected final int fInitialDepth;

        
Element depth. /** Element depth. */
        protected int fElementDepth;

        
Depth at match. /** Depth at match. */
        protected int fMatchedDepth;

        //
        // Constructors
        //

        
Constructs a selector matcher. /** Constructs a selector matcher. */
        public Matcher(Selector.XPath xpath, FieldActivator activator,
                int initialDepth) {
            super(xpath);
            fFieldActivator = activator;
            fInitialDepth = initialDepth;
        } // <init>(Selector.XPath,FieldActivator)

        //
        // XMLDocumentFragmentHandler methods
        //

        public void startDocumentFragment(){
            super.startDocumentFragment();
            fElementDepth = 0;
            fMatchedDepth = -1;
        } // startDocumentFragment()

        
The start of an element. If the document specifies the start element
by using an empty tag, then the startElement method will immediately
be followed by the endElement method, with no intervening methods.
Params:
element –    The name of the element.
attributes – The element attributes./**
         * The start of an element. If the document specifies the start element
         * by using an empty tag, then the startElement method will immediately
         * be followed by the endElement method, with no intervening methods.
         * 
         * @param element    The name of the element.
         * @param attributes The element attributes. 
         *
         */
        public void startElement(QName element, XMLAttributes attributes) {
            super.startElement(element, attributes);
            fElementDepth++;
            // activate the fields, if selector is matched
            //int matched = isMatched();

            if (isMatched()) {
/*            (fMatchedDepth == -1 && ((matched & MATCHED) == MATCHED)) ||
                    ((matched & MATCHED_DESCENDANT) == MATCHED_DESCENDANT)) { */
                fMatchedDepth = fElementDepth;
                fFieldActivator.startValueScopeFor(fIdentityConstraint, fInitialDepth);
                int count = fIdentityConstraint.getFieldCount();
                for (int i = 0; i < count; i++) {
                    Field field = fIdentityConstraint.getFieldAt(i);
                    XPathMatcher matcher = fFieldActivator.activateField(field, fInitialDepth);
                    matcher.startElement(element, attributes);
                }
            }

        } // startElement(QName,XMLAttrList,int)

        public void endElement(QName element, XSTypeDefinition type, boolean nillable, Object actualValue, short valueType, ShortList itemValueType) {
            super.endElement(element, type, nillable, actualValue, valueType, itemValueType);
            if (fElementDepth-- == fMatchedDepth) {
                fMatchedDepth = -1;
                fFieldActivator.endValueScopeFor(fIdentityConstraint, fInitialDepth);
            }
        }

        
Returns the identity constraint. /** Returns the identity constraint. */
        public IdentityConstraint getIdentityConstraint() {
            return fIdentityConstraint;
        } // getIdentityConstraint():IdentityConstraint

        
get the initial depth at which this selector matched. /** get the initial depth at which this selector matched. */
        public int getInitialDepth() {
            return fInitialDepth;
        } // getInitialDepth():  int


    } // class Matcher

} // class Selector