/*
 * Copyright (c) 2004 World Wide Web Consortium,
 *
 * (Massachusetts Institute of Technology, European Research Consortium for
 * Informatics and Mathematics, Keio University). All Rights Reserved. This
 * work is distributed under the W3C(r) Software License [1] in the hope that
 * it will be useful, but WITHOUT ANY WARRANTY; without even the implied
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 *
 * [1] http://www.w3.org/Consortium/Legal/2002/copyright-software-20021231
 */

package org.w3c.dom;

/**
 * The <code>DOMImplementation</code> interface provides a number of methods 
 * for performing operations that are independent of any particular instance 
 * of the document object model.
 * <p>See also the <a href='http://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407'>Document Object Model (DOM) Level 3 Core Specification</a>.
 */
public interface DOMImplementation {
    /**
     * Test if the DOM implementation implements a specific feature and 
     * version, as specified in <a href="http://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/core.html#DOMFeatures">DOM Features</a>.
     * @param feature  The name of the feature to test. 
     * @param version  This is the version number of the feature to test. 
     * @return <code>true</code> if the feature is implemented in the 
     *   specified version, <code>false</code> otherwise.
     */
    public boolean hasFeature(String feature, 
                              String version);

    /**
     * Creates an empty <code>DocumentType</code> node. Entity declarations 
     * and notations are not made available. Entity reference expansions and 
     * default attribute additions do not occur..
     * @param qualifiedName The qualified name of the document type to be 
     *   created.
     * @param publicId The external subset public identifier.
     * @param systemId The external subset system identifier.
     * @return A new <code>DocumentType</code> node with 
     *   <code>Node.ownerDocument</code> set to <code>null</code>.
     * @exception DOMException
     *   INVALID_CHARACTER_ERR: Raised if the specified qualified name is not 
     *   an XML name according to [<a href='http://www.w3.org/TR/2004/REC-xml-20040204'>XML 1.0</a>].
     *   <br>NAMESPACE_ERR: Raised if the <code>qualifiedName</code> is 
     *   malformed.
     *   <br>NOT_SUPPORTED_ERR: May be raised if the implementation does not 
     *   support the feature "XML" and the language exposed through the 
     *   Document does not support XML Namespaces (such as [<a href='http://www.w3.org/TR/1999/REC-html401-19991224/'>HTML 4.01</a>]). 
     * @since DOM Level 2
     */
    public DocumentType createDocumentType(String qualifiedName, 
                                           String publicId, 
                                           String systemId)
                                           throws DOMException;

    /**
     * Creates a DOM Document object of the specified type with its document 
     * element.
     * <br>Note that based on the <code>DocumentType</code> given to create 
     * the document, the implementation may instantiate specialized 
     * <code>Document</code> objects that support additional features than 
     * the "Core", such as "HTML" [<a href='http://www.w3.org/TR/2003/REC-DOM-Level-2-HTML-20030109'>DOM Level 2 HTML</a>]
     * . On the other hand, setting the <code>DocumentType</code> after the 
     * document was created makes this very unlikely to happen. 
     * Alternatively, specialized <code>Document</code> creation methods, 
     * such as <code>createHTMLDocument</code> [<a href='http://www.w3.org/TR/2003/REC-DOM-Level-2-HTML-20030109'>DOM Level 2 HTML</a>]
     * , can be used to obtain specific types of <code>Document</code> 
     * objects.
     * @param namespaceURI The namespace URI of the document element to 
     *   create or <code>null</code>.
     * @param qualifiedName The qualified name of the document element to be 
     *   created or <code>null</code>.
     * @param doctype The type of document to be created or <code>null</code>.
     *   When <code>doctype</code> is not <code>null</code>, its 
     *   <code>Node.ownerDocument</code> attribute is set to the document 
     *   being created.
     * @return A new <code>Document</code> object with its document element. 
     *   If the <code>NamespaceURI</code>, <code>qualifiedName</code>, and 
     *   <code>doctype</code> are <code>null</code>, the returned 
     *   <code>Document</code> is empty with no document element.
     * @exception DOMException
     *   INVALID_CHARACTER_ERR: Raised if the specified qualified name is not 
     *   an XML name according to [<a href='http://www.w3.org/TR/2004/REC-xml-20040204'>XML 1.0</a>].
     *   <br>NAMESPACE_ERR: Raised if the <code>qualifiedName</code> is 
     *   malformed, if the <code>qualifiedName</code> has a prefix and the 
     *   <code>namespaceURI</code> is <code>null</code>, or if the 
     *   <code>qualifiedName</code> is <code>null</code> and the 
     *   <code>namespaceURI</code> is different from <code>null</code>, or 
     *   if the <code>qualifiedName</code> has a prefix that is "xml" and 
     *   the <code>namespaceURI</code> is different from "<a href='http://www.w3.org/XML/1998/namespace'>
     *   http://www.w3.org/XML/1998/namespace</a>" [<a href='http://www.w3.org/TR/1999/REC-xml-names-19990114/'>XML Namespaces</a>]
     *   , or if the DOM implementation does not support the 
     *   <code>"XML"</code> feature but a non-null namespace URI was 
     *   provided, since namespaces were defined by XML.
     *   <br>WRONG_DOCUMENT_ERR: Raised if <code>doctype</code> has already 
     *   been used with a different document or was created from a different 
     *   implementation.
     *   <br>NOT_SUPPORTED_ERR: May be raised if the implementation does not 
     *   support the feature "XML" and the language exposed through the 
     *   Document does not support XML Namespaces (such as [<a href='http://www.w3.org/TR/1999/REC-html401-19991224/'>HTML 4.01</a>]). 
     * @since DOM Level 2
     */
    public Document createDocument(String namespaceURI, 
                                   String qualifiedName, 
                                   DocumentType doctype)
                                   throws DOMException;

    /**
     *  This method returns a specialized object which implements the 
     * specialized APIs of the specified feature and version, as specified 
     * in <a href="http://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/core.html#DOMFeatures">DOM Features</a>. The specialized object may also be obtained by using 
     * binding-specific casting methods but is not necessarily expected to, 
     * as discussed in . This method also allow the implementation to 
     * provide specialized objects which do not support the 
     * <code>DOMImplementation</code> interface. 
     * @param feature  The name of the feature requested. Note that any plus 
     *   sign "+" prepended to the name of the feature will be ignored since 
     *   it is not significant in the context of this method. 
     * @param version  This is the version number of the feature to test. 
     * @return  Returns an object which implements the specialized APIs of 
     *   the specified feature and version, if any, or <code>null</code> if 
     *   there is no object which implements interfaces associated with that 
     *   feature. If the <code>DOMObject</code> returned by this method 
     *   implements the <code>DOMImplementation</code> interface, it must 
     *   delegate to the primary core <code>DOMImplementation</code> and not 
     *   return results inconsistent with the primary core 
     *   <code>DOMImplementation</code> such as <code>hasFeature</code>, 
     *   <code>getFeature</code>, etc. 
     * @since DOM Level 3
     */
    public Object getFeature(String feature, 
                             String version);

}