/*
 * 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: XPathFactoryImpl.java 1225277 2011-12-28 18:50:56Z mrglavas $

package org.apache.xpath.jaxp;

import org.apache.xpath.res.XPATHErrorResources;
import org.apache.xalan.res.XSLMessages;

import javax.xml.XMLConstants;
import javax.xml.xpath.XPathFactory;
import javax.xml.xpath.XPathFactoryConfigurationException;
import javax.xml.xpath.XPathFunctionResolver;
import javax.xml.xpath.XPathVariableResolver;

The XPathFactory builds XPaths.
Author:
 Ramesh Mandava
Version:
$Revision: 1225277 $/**
 * The XPathFactory builds XPaths.
 *
 * @version $Revision: 1225277 $
 * @author  Ramesh Mandava
 */
public class XPathFactoryImpl extends XPathFactory {
	
	
Name of class as a constant to use for debugging.
/**
	 * <p>Name of class as a constant to use for debugging.</p>
	 */
	private static final String CLASS_NAME = "XPathFactoryImpl";
	
	
XPathFunctionResolver for this XPathFactory and created XPaths.
/**
	 *<p>XPathFunctionResolver for this XPathFactory and created XPaths.</p>
	 */
	private XPathFunctionResolver xPathFunctionResolver = null;
	
	
XPathVariableResolver for this XPathFactory and created XPaths
/**
	 * <p>XPathVariableResolver for this XPathFactory and created XPaths</p>
	 */
	private XPathVariableResolver xPathVariableResolver = null;

	
State of secure processing feature.
/**
	 * <p>State of secure processing feature.</p>
	 */
	private boolean featureSecureProcessing = false;
		
	
Is specified object model supported by this 
XPathFactory?
Params:
objectModel – Specifies the object model which the returned
XPathFactory will understand.
Throws:
NullPointerException – If objectModel is null.
IllegalArgumentException – If objectModel.length() == 0.
Returns:
true if XPathFactory supports 
objectModel, else false./**
	 * <p>Is specified object model supported by this 
         * <code>XPathFactory</code>?</p>
	 * 
	 * @param objectModel Specifies the object model which the returned
         * <code>XPathFactory</code> will understand.
	 *  
	 * @return <code>true</code> if <code>XPathFactory</code> supports 
         * <code>objectModel</code>, else <code>false</code>.
	 * 
	 * @throws NullPointerException If <code>objectModel</code> is <code>null</code>.
	 * @throws IllegalArgumentException If <code>objectModel.length() == 0</code>.
	 */
	public boolean isObjectModelSupported(String objectModel) {
		
            if (objectModel == null) {
                String fmsg = XSLMessages.createXPATHMessage(
                        XPATHErrorResources.ER_OBJECT_MODEL_NULL,
                        new Object[] { this.getClass().getName() } );

                throw new NullPointerException( fmsg );
            }
		
            if (objectModel.length() == 0) {
                String fmsg = XSLMessages.createXPATHMessage(
                        XPATHErrorResources.ER_OBJECT_MODEL_EMPTY,
                        new Object[] { this.getClass().getName() } );
                throw new IllegalArgumentException( fmsg );
            }
		
	    // know how to support default object model, W3C DOM
            if (objectModel.equals(XPathFactory.DEFAULT_OBJECT_MODEL_URI)) {
                return true;
            }
		
            // don't know how to support anything else
            return false;
	}

        
Returns a new XPath object using the underlying
object model determined when the factory was instantiated.
Returns:
New XPath/**
         * <p>Returns a new <code>XPath</code> object using the underlying
         * object model determined when the factory was instantiated.</p>
	 * 
	 * @return New <code>XPath</code>
	 */
	public javax.xml.xpath.XPath newXPath() {
	    return new org.apache.xpath.jaxp.XPathImpl(
                    xPathVariableResolver, xPathFunctionResolver,
                    featureSecureProcessing );
	}
	    
	
Set a feature for this XPathFactory and 
XPaths created by this factory.
 Feature names are fully qualified URIs. Implementations may define their own features. An XPathFactoryConfigurationException is thrown if this XPathFactory or the XPaths
 it creates cannot support the feature.
It is possible for an XPathFactory to expose a feature
value but be unable to change its state.

See XPathFactory for full documentation of specific features.
Params:
name – Feature name.
value – Is feature state true or false.
Throws:
XPathFactoryConfigurationException – if this 
XPathFactory or the XPaths
  it creates cannot support this feature.
NullPointerException – if name is 
null./**
	 * <p>Set a feature for this <code>XPathFactory</code> and 
         * <code>XPath</code>s created by this factory.</p>
	 * 
	 * <p>
	 * Feature names are fully qualified {@link java.net.URI}s.
	 * Implementations may define their own features.
	 * An {@link XPathFactoryConfigurationException} is thrown if this
         * <code>XPathFactory</code> or the <code>XPath</code>s
	 *  it creates cannot support the feature.
	 * It is possible for an <code>XPathFactory</code> to expose a feature
         * value but be unable to change its state.
	 * </p>
	 * 
	 * <p>See {@link javax.xml.xpath.XPathFactory} for full documentation
         * of specific features.</p>
	 * 
	 * @param name Feature name.
	 * @param value Is feature state <code>true</code> or <code>false</code>.
	 *  
	 * @throws XPathFactoryConfigurationException if this 
         * <code>XPathFactory</code> or the <code>XPath</code>s
	 *   it creates cannot support this feature.
         * @throws NullPointerException if <code>name</code> is 
         * <code>null</code>.
	 */
	public void setFeature(String name, boolean value)
		throws XPathFactoryConfigurationException {
			
            // feature name cannot be null
            if (name == null) {
                String fmsg = XSLMessages.createXPATHMessage(
                        XPATHErrorResources.ER_FEATURE_NAME_NULL,
                        new Object[] { CLASS_NAME, value ? Boolean.TRUE : Boolean.FALSE } );
                throw new NullPointerException( fmsg );
             }
		
            // secure processing?
            if (name.equals(XMLConstants.FEATURE_SECURE_PROCESSING)) {

                featureSecureProcessing = value;
						
                // all done processing feature
                return;
            }
		
            // unknown feature
            String fmsg = XSLMessages.createXPATHMessage(
                    XPATHErrorResources.ER_FEATURE_UNKNOWN,
                    new Object[] { name, CLASS_NAME, value ? Boolean.TRUE : Boolean.FALSE } );
            throw new XPathFactoryConfigurationException( fmsg );
	}

	
Get the state of the named feature.
 Feature names are fully qualified URIs. Implementations may define their own features. An XPathFactoryConfigurationException is thrown if this XPathFactory or the XPaths
it creates cannot support the feature.
It is possible for an XPathFactory to expose a feature 
value but be unable to change its state.

Params:
name – Feature name.
Throws:
XPathFactoryConfigurationException – if this 
XPathFactory or the XPaths
  it creates cannot support this feature.
NullPointerException – if name is 
null.
Returns:
State of the named feature./**
	 * <p>Get the state of the named feature.</p>
	 * 
	 * <p>
	 * Feature names are fully qualified {@link java.net.URI}s.
	 * Implementations may define their own features.
	 * An {@link XPathFactoryConfigurationException} is thrown if this
         * <code>XPathFactory</code> or the <code>XPath</code>s
	 * it creates cannot support the feature.
	 * It is possible for an <code>XPathFactory</code> to expose a feature 
         * value but be unable to change its state.
	 * </p>
	 * 
	 * @param name Feature name.
	 * 
	 * @return State of the named feature.
	 * 
	 * @throws XPathFactoryConfigurationException if this 
         * <code>XPathFactory</code> or the <code>XPath</code>s
	 *   it creates cannot support this feature.
         * @throws NullPointerException if <code>name</code> is 
         * <code>null</code>.
	 */
	public boolean getFeature(String name)
		throws XPathFactoryConfigurationException {

            // feature name cannot be null
            if (name == null) {
                String fmsg = XSLMessages.createXPATHMessage(
                        XPATHErrorResources.ER_GETTING_NULL_FEATURE,
                        new Object[] { CLASS_NAME } );
                throw new NullPointerException( fmsg );
            }
		
            // secure processing?
            if (name.equals(XMLConstants.FEATURE_SECURE_PROCESSING)) {
                return featureSecureProcessing;
            }
		
            // unknown feature
            String fmsg = XSLMessages.createXPATHMessage(
                    XPATHErrorResources.ER_GETTING_UNKNOWN_FEATURE,
                    new Object[] { name, CLASS_NAME } );

            throw new XPathFactoryConfigurationException( fmsg );
        }
		
	
Establish a default function resolver.
Any XPath objects constructed from this factory will use
the specified resolver by default.
A NullPointerException is thrown if 
resolver is null.
Params:
resolver – XPath function resolver.
Throws:
NullPointerException – If resolver is 
null./**
         * <p>Establish a default function resolver.</p>
         * 
	 * <p>Any <code>XPath</code> objects constructed from this factory will use
	 * the specified resolver by default.</p>
	 *
	 * <p>A <code>NullPointerException</code> is thrown if 
         * <code>resolver</code> is <code>null</code>.</p>
         * 
	 * @param resolver XPath function resolver.
	 * 
	 * @throws NullPointerException If <code>resolver</code> is 
         * <code>null</code>.
	 */
        public void setXPathFunctionResolver(XPathFunctionResolver resolver) {
			
            // resolver cannot be null
            if (resolver == null) {
                String fmsg = XSLMessages.createXPATHMessage(
                        XPATHErrorResources.ER_NULL_XPATH_FUNCTION_RESOLVER,
                        new Object[] {  CLASS_NAME } );
                throw new NullPointerException( fmsg );
            }
			
            xPathFunctionResolver = resolver;
        }
		
	
Establish a default variable resolver.
Any XPath objects constructed from this factory will use
the specified resolver by default.
A NullPointerException is thrown if resolver is null.
Params:
resolver – Variable resolver.
 @throws NullPointerException If resolver is 
null./**
	 * <p>Establish a default variable resolver.</p>
	 *
	 * <p>Any <code>XPath</code> objects constructed from this factory will use
	 * the specified resolver by default.</p>
	 * 
	 * <p>A <code>NullPointerException</code> is thrown if <code>resolver</code> is <code>null</code>.</p>
	 * 
	 * @param resolver Variable resolver.
	 * 
	 *  @throws NullPointerException If <code>resolver</code> is 
         * <code>null</code>.
	 */
	public void setXPathVariableResolver(XPathVariableResolver resolver) {

		// resolver cannot be null
		if (resolver == null) {
                    String fmsg = XSLMessages.createXPATHMessage(
                            XPATHErrorResources.ER_NULL_XPATH_VARIABLE_RESOLVER,
                            new Object[] {  CLASS_NAME } );
		    throw new NullPointerException( fmsg );
		}
			
		xPathVariableResolver = resolver;
	}
}