/*
 * Copyright 2002 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */

package javax.xml.parsers;

import java.io.InputStream;
import java.io.IOException;
import java.io.File;
import java.io.FileInputStream;

import java.util.Properties;
import java.io.BufferedReader;
import java.io.InputStreamReader;

/**
 * Defines a factory API that enables applications to obtain a
 * parser that produces DOM object trees from XML documents.
 *
 * An implementation of the <code>DocumentBuilderFactory</code> class is
 * <em>NOT</em> guaranteed to be thread safe. It is up to the user application 
 * to make sure about the use of the <code>DocumentBuilderFactory</code> from 
 * more than one thread. Alternatively the application can have one instance 
 * of the <code>DocumentBuilderFactory</code> per thread.
 * An application can use the same instance of the factory to obtain one or 
 * more instances of the <code>DocumentBuilder</code> provided the instance
 * of the factory isn't being used in more than one thread at a time.
 *
 * @since JAXP 1.0
 * @version 1.0
 */

public abstract class DocumentBuilderFactory {
    private boolean validating = false;
    private boolean namespaceAware = false;
    private boolean whitespace = false;
    private boolean expandEntityRef = true;
    private boolean ignoreComments = false;
    private boolean coalescing = false;
    
    protected DocumentBuilderFactory () {
    
    }

    /**
     * Obtain a new instance of a
     * <code>DocumentBuilderFactory</code>. This static method creates
     * a new factory instance.
     * This method uses the following ordered lookup procedure to determine
     * the <code>DocumentBuilderFactory</code> implementation class to
     * load:
     * <ul>
     * <li>
     * Use the <code>javax.xml.parsers.DocumentBuilderFactory</code> system
     * property.
     * </li>
     * <li>
     * Use the properties file "lib/jaxp.properties" in the JRE directory.
     * This configuration file is in standard <code>java.util.Properties
     * </code> format and contains the fully qualified name of the
     * implementation class with the key being the system property defined
     * above.
     * </li>
     * <li>
     * Use the Services API (as detailed in the JAR specification), if
     * available, to determine the classname. The Services API will look
     * for a classname in the file
     * <code>META-INF/services/javax.xml.parsers.DocumentBuilderFactory</code>
     * in jars available to the runtime.
     * </li>
     * <li>
     * Platform default <code>DocumentBuilderFactory</code> instance.
     * </li>
     * </ul>
     *
     * Once an application has obtained a reference to a
     * <code>DocumentBuilderFactory</code> it can use the factory to
     * configure and obtain parser instances.
     *
     * @exception FactoryConfigurationError if the implementation is not
     * available or cannot be instantiated.
     */
    
    public static DocumentBuilderFactory newInstance()
        throws FactoryConfigurationError
    {
        try {
            return (DocumentBuilderFactory) FactoryFinder.find(
                /* The default property name according to the JAXP spec */
                "javax.xml.parsers.DocumentBuilderFactory",
                /* The fallback implementation class name */
                "org.apache.crimson.jaxp.DocumentBuilderFactoryImpl");
        } catch (FactoryFinder.ConfigurationError e) {
            throw new FactoryConfigurationError(e.getException(),
                                                e.getMessage());
        }
    }
    
    /**
     * Creates a new instance of a {@link javax.xml.parsers.DocumentBuilder}
     * using the currently configured parameters.
     *
     * @exception ParserConfigurationException if a DocumentBuilder
     * cannot be created which satisfies the configuration requested.
     * @return A new instance of a DocumentBuilder.
     */
    
    public abstract DocumentBuilder newDocumentBuilder()
        throws ParserConfigurationException;
    
    
    /**
     * Specifies that the parser produced by this code will
     * provide support for XML namespaces. By default the value of this is set
     * to <code>false</code>
     *
     * @param awareness true if the parser produced will provide support
     *                  for XML namespaces; false otherwise.
     */
    
    public void setNamespaceAware(boolean awareness) {
        this.namespaceAware = awareness;
    }

    /**
     * Specifies that the parser produced by this code will
     * validate documents as they are parsed. By default the value of this
     * is set to <code>false</code>.
     *
     * @param validating true if the parser produced will validate documents
     *                   as they are parsed; false otherwise.
     */
    
    public void setValidating(boolean validating) {
        this.validating = validating;
    }

    /**
     * Specifies that the parsers created by this  factory must eliminate
     * whitespace in element content (sometimes known loosely as
     * 'ignorable whitespace') when parsing XML documents (see XML Rec
     * 2.10). Note that only whitespace which is directly contained within
     * element content that has an element only content model (see XML
     * Rec 3.2.1) will be eliminated. Due to reliance on the content model
     * this setting requires the parser to be in validating mode. By default
     * the value of this is set to <code>false</code>.
     *
     * @param whitespace true if the parser created must eliminate whitespace
     *                   in the element content when parsing XML documents;
     *                   false otherwise.
     */

    public void setIgnoringElementContentWhitespace(boolean whitespace) {
        this.whitespace = whitespace;
    }

    /**
     * Specifies that the parser produced by this code will
     * expand entity reference nodes. By default the value of this is set to
     * <code>true</code>
     *
     * @param expandEntityRef true if the parser produced will expand entity
     *                        reference nodes; false otherwise.
     */
    
    public void setExpandEntityReferences(boolean expandEntityRef) {
        this.expandEntityRef = expandEntityRef;
    }

    /**
     * Specifies that the parser produced by this code will
     * ignore comments. By default the value of this is set to <code>false
     * </code>
     */
    
    public void setIgnoringComments(boolean ignoreComments) {
        this.ignoreComments = ignoreComments;
    }

    /**
     * Specifies that the parser produced by this code will
     * convert CDATA nodes to Text nodes and append it to the
     * adjacent (if any) text node. By default the value of this is set to
     * <code>false</code>
     *
     * @param coalescing  true if the parser produced will convert CDATA nodes
     *                    to Text nodes and append it to the adjacent (if any)
     *                    text node; false otherwise.
     */
    
    public void setCoalescing(boolean coalescing) {
        this.coalescing = coalescing;
    }

    /**
     * Indicates whether or not the factory is configured to produce
     * parsers which are namespace aware.
     *
     * @return  true if the factory is configured to produce parsers which
     *          are namespace aware; false otherwise.
     */
    
    public boolean isNamespaceAware() {
        return namespaceAware;
    }

    /**
     * Indicates whether or not the factory is configured to produce
     * parsers which validate the XML content during parse.
     *
     * @return  true if the factory is configured to produce parsers
     *          which validate the XML content during parse; false otherwise.
     */
    
    public boolean isValidating() {
        return validating;
    }

    /**
     * Indicates whether or not the factory is configured to produce
     * parsers which ignore ignorable whitespace in element content.
     *
     * @return  true if the factory is configured to produce parsers
     *          which ignore ignorable whitespace in element content;
     *          false otherwise.
     */
    
    public boolean isIgnoringElementContentWhitespace() {
        return whitespace;
    }

    /**
     * Indicates whether or not the factory is configured to produce
     * parsers which expand entity reference nodes.
     *
     * @return  true if the factory is configured to produce parsers
     *          which expand entity reference nodes; false otherwise.
     */
    
    public boolean isExpandEntityReferences() {
        return expandEntityRef;
    }

    /**
     * Indicates whether or not the factory is configured to produce
     * parsers which ignores comments.
     *
     * @return  true if the factory is configured to produce parsers
     *          which ignores comments; false otherwise.
     */
    
    public boolean isIgnoringComments() {
        return ignoreComments;
    }

    /**
     * Indicates whether or not the factory is configured to produce
     * parsers which converts CDATA nodes to Text nodes and appends it to
     * the adjacent (if any) Text node.
     *
     * @return  true if the factory is configured to produce parsers
     *          which converts CDATA nodes to Text nodes and appends it to
     *          the adjacent (if any) Text node; false otherwise.
     */
    
    public boolean isCoalescing() {
        return coalescing;
    }

    /**
     * Allows the user to set specific attributes on the underlying
     * implementation.
     * @param name The name of the attribute.
     * @param value The value of the attribute.
     * @exception IllegalArgumentException thrown if the underlying
     * implementation doesn't recognize the attribute.
     */
    public abstract void setAttribute(String name, Object value)
                throws IllegalArgumentException;

    /**
     * Allows the user to retrieve specific attributes on the underlying
     * implementation.
     * @param name The name of the attribute.
     * @return value The value of the attribute.
     * @exception IllegalArgumentException thrown if the underlying
     * implementation doesn't recognize the attribute.
     */
    public abstract Object getAttribute(String name)
                throws IllegalArgumentException;
}