/*
 * Copyright (c) 2000 World Wide Web Consortium,
 * (Massachusetts Institute of Technology, Institut National de
 * Recherche en Informatique et en Automatique, Keio University). All
 * Rights Reserved. This program is distributed under the W3C's Software
 * Intellectual Property License. This program is distributed 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.
 * See W3C License http://www.w3.org/Consortium/Legal/ for more details.
 */

package org.w3c.dom;

/**
 * The <code>Document</code> interface represents the entire HTML or XML 
 * document. Conceptually, it is the root of the document tree, and provides 
 * the primary access to the document's data.
 * <p>Since elements, text nodes, comments, processing instructions, etc. 
 * cannot exist outside the context of a <code>Document</code>, the 
 * <code>Document</code> interface also contains the factory methods needed 
 * to create these objects. The <code>Node</code> objects created have a 
 * <code>ownerDocument</code> attribute which associates them with the 
 * <code>Document</code> within whose context they were created.
 * <p>See also the <a href='http://www.w3.org/TR/2000/REC-DOM-Level-2-Core-20001113'>Document Object Model (DOM) Level 2 Core Specification</a>.
 */
public interface Document extends Node {
    /**
     * The Document Type Declaration (see <code>DocumentType</code>) 
     * associated with this document. For HTML documents as well as XML 
     * documents without a document type declaration this returns 
     * <code>null</code>. The DOM Level 2 does not support editing the 
     * Document Type Declaration. <code>docType</code> cannot be altered in 
     * any way, including through the use of methods inherited from the 
     * <code>Node</code> interface, such as <code>insertNode</code> or 
     * <code>removeNode</code>.
     */
    public DocumentType getDoctype();

    /**
     * The <code>DOMImplementation</code> object that handles this document. A 
     * DOM application may use objects from multiple implementations.
     */
    public DOMImplementation getImplementation();

    /**
     * This is a convenience attribute that allows direct access to the child 
     * node that is the root element of the document. For HTML documents, 
     * this is the element with the tagName "HTML".
     */
    public Element getDocumentElement();

    /**
     * Creates an element of the type specified. Note that the instance 
     * returned implements the <code>Element</code> interface, so attributes 
     * can be specified directly on the returned object.
     * <br>In addition, if there are known attributes with default values, 
     * <code>Attr</code> nodes representing them are automatically created 
     * and attached to the element.
     * <br>To create an element with a qualified name and namespace URI, use 
     * the <code>createElementNS</code> method.
     * @param tagNameThe name of the element type to instantiate. For XML, 
     *   this is case-sensitive. For HTML, the <code>tagName</code> 
     *   parameter may be provided in any case, but it must be mapped to the 
     *   canonical uppercase form by the DOM implementation. 
     * @return A new <code>Element</code> object with the 
     *   <code>nodeName</code> attribute set to <code>tagName</code>, and 
     *   <code>localName</code>, <code>prefix</code>, and 
     *   <code>namespaceURI</code> set to <code>null</code>.
     * @exception DOMException
     *   INVALID_CHARACTER_ERR: Raised if the specified name contains an 
     *   illegal character.
     */
    public Element createElement(String tagName)
                                 throws DOMException;

    /**
     * Creates an empty <code>DocumentFragment</code> object. 
     * @return A new <code>DocumentFragment</code>.
     */
    public DocumentFragment createDocumentFragment();

    /**
     * Creates a <code>Text</code> node given the specified string.
     * @param dataThe data for the node.
     * @return The new <code>Text</code> object.
     */
    public Text createTextNode(String data);

    /**
     * Creates a <code>Comment</code> node given the specified string.
     * @param dataThe data for the node.
     * @return The new <code>Comment</code> object.
     */
    public Comment createComment(String data);

    /**
     * Creates a <code>CDATASection</code> node whose value is the specified 
     * string.
     * @param dataThe data for the <code>CDATASection</code> contents.
     * @return The new <code>CDATASection</code> object.
     * @exception DOMException
     *   NOT_SUPPORTED_ERR: Raised if this document is an HTML document.
     */
    public CDATASection createCDATASection(String data)
                                           throws DOMException;

    /**
     * Creates a <code>ProcessingInstruction</code> node given the specified 
     * name and data strings.
     * @param targetThe target part of the processing instruction.
     * @param dataThe data for the node.
     * @return The new <code>ProcessingInstruction</code> object.
     * @exception DOMException
     *   INVALID_CHARACTER_ERR: Raised if the specified target contains an 
     *   illegal character.
     *   <br>NOT_SUPPORTED_ERR: Raised if this document is an HTML document.
     */
    public ProcessingInstruction createProcessingInstruction(String target, 
                                                             String data)
                                                             throws DOMException;

    /**
     * Creates an <code>Attr</code> of the given name. Note that the 
     * <code>Attr</code> instance can then be set on an <code>Element</code> 
     * using the <code>setAttributeNode</code> method. 
     * <br>To create an attribute with a qualified name and namespace URI, use 
     * the <code>createAttributeNS</code> method.
     * @param nameThe name of the attribute.
     * @return A new <code>Attr</code> object with the <code>nodeName</code> 
     *   attribute set to <code>name</code>, and <code>localName</code>, 
     *   <code>prefix</code>, and <code>namespaceURI</code> set to 
     *   <code>null</code>. The value of the attribute is the empty string.
     * @exception DOMException
     *   INVALID_CHARACTER_ERR: Raised if the specified name contains an 
     *   illegal character.
     */
    public Attr createAttribute(String name)
                                throws DOMException;

    /**
     * Creates an <code>EntityReference</code> object. In addition, if the 
     * referenced entity is known, the child list of the 
     * <code>EntityReference</code> node is made the same as that of the 
     * corresponding <code>Entity</code> node.If any descendant of the 
     * <code>Entity</code> node has an unbound namespace prefix, the 
     * corresponding descendant of the created <code>EntityReference</code> 
     * node is also unbound; (its <code>namespaceURI</code> is 
     * <code>null</code>). The DOM Level 2 does not support any mechanism to 
     * resolve namespace prefixes.
     * @param nameThe name of the entity to reference. 
     * @return The new <code>EntityReference</code> object.
     * @exception DOMException
     *   INVALID_CHARACTER_ERR: Raised if the specified name contains an 
     *   illegal character.
     *   <br>NOT_SUPPORTED_ERR: Raised if this document is an HTML document.
     */
    public EntityReference createEntityReference(String name)
                                                 throws DOMException;

    /**
     * Returns a <code>NodeList</code> of all the <code>Elements</code> with a 
     * given tag name in the order in which they are encountered in a 
     * preorder traversal of the <code>Document</code> tree. 
     * @param tagnameThe name of the tag to match on. The special value "*" 
     *   matches all tags.
     * @return A new <code>NodeList</code> object containing all the matched 
     *   <code>Elements</code>.
     */
    public NodeList getElementsByTagName(String tagname);

    /**
     * Imports a node from another document to this document. The returned 
     * node has no parent; (<code>parentNode</code> is <code>null</code>). 
     * The source node is not altered or removed from the original document; 
     * this method creates a new copy of the source node.
     * <br>For all nodes, importing a node creates a node object owned by the 
     * importing document, with attribute values identical to the source 
     * node's <code>nodeName</code> and <code>nodeType</code>, plus the 
     * attributes related to namespaces (<code>prefix</code>, 
     * <code>localName</code>, and <code>namespaceURI</code>). As in the 
     * <code>cloneNode</code> operation on a <code>Node</code>, the source 
     * node is not altered.
     * <br>Additional information is copied as appropriate to the 
     * <code>nodeType</code>, attempting to mirror the behavior expected if 
     * a fragment of XML or HTML source was copied from one document to 
     * another, recognizing that the two documents may have different DTDs 
     * in the XML case. The following list describes the specifics for each 
     * type of node. 
     * <dl>
     * <dt>ATTRIBUTE_NODE</dt>
     * <dd>The <code>ownerElement</code> attribute 
     * is set to <code>null</code> and the <code>specified</code> flag is 
     * set to <code>true</code> on the generated <code>Attr</code>. The 
     * descendants of the source <code>Attr</code> are recursively imported 
     * and the resulting nodes reassembled to form the corresponding subtree.
     * Note that the <code>deep</code> parameter has no effect on 
     * <code>Attr</code> nodes; they always carry their children with them 
     * when imported.</dd>
     * <dt>DOCUMENT_FRAGMENT_NODE</dt>
     * <dd>If the <code>deep</code> option 
     * was set to <code>true</code>, the descendants of the source element 
     * are recursively imported and the resulting nodes reassembled to form 
     * the corresponding subtree. Otherwise, this simply generates an empty 
     * <code>DocumentFragment</code>.</dd>
     * <dt>DOCUMENT_NODE</dt>
     * <dd><code>Document</code> 
     * nodes cannot be imported.</dd>
     * <dt>DOCUMENT_TYPE_NODE</dt>
     * <dd><code>DocumentType</code> 
     * nodes cannot be imported.</dd>
     * <dt>ELEMENT_NODE</dt>
     * <dd>Specified attribute nodes of the 
     * source element are imported, and the generated <code>Attr</code> 
     * nodes are attached to the generated <code>Element</code>. Default 
     * attributes are not copied, though if the document being imported into 
     * defines default attributes for this element name, those are assigned. 
     * If the <code>importNode</code> <code>deep</code> parameter was set to 
     * <code>true</code>, the descendants of the source element are 
     * recursively imported and the resulting nodes reassembled to form the 
     * corresponding subtree.</dd>
     * <dt>ENTITY_NODE</dt>
     * <dd><code>Entity</code> nodes can be 
     * imported, however in the current release of the DOM the 
     * <code>DocumentType</code> is readonly. Ability to add these imported 
     * nodes to a <code>DocumentType</code> will be considered for addition 
     * to a future release of the DOM.On import, the <code>publicId</code>, 
     * <code>systemId</code>, and <code>notationName</code> attributes are 
     * copied. If a <code>deep</code> import is requested, the descendants 
     * of the the source <code>Entity</code> are recursively imported and 
     * the resulting nodes reassembled to form the corresponding subtree.</dd>
     * <dt>
     * ENTITY_REFERENCE_NODE</dt>
     * <dd>Only the <code>EntityReference</code> itself is 
     * copied, even if a <code>deep</code> import is requested, since the 
     * source and destination documents might have defined the entity 
     * differently. If the document being imported into provides a 
     * definition for this entity name, its value is assigned.</dd>
     * <dt>NOTATION_NODE</dt>
     * <dd>
     * <code>Notation</code> nodes can be imported, however in the current 
     * release of the DOM the <code>DocumentType</code> is readonly. Ability 
     * to add these imported nodes to a <code>DocumentType</code> will be 
     * considered for addition to a future release of the DOM.On import, the 
     * <code>publicId</code> and <code>systemId</code> attributes are copied.
     * Note that the <code>deep</code> parameter has no effect on 
     * <code>Notation</code> nodes since they never have any children.</dd>
     * <dt>
     * PROCESSING_INSTRUCTION_NODE</dt>
     * <dd>The imported node copies its 
     * <code>target</code> and <code>data</code> values from those of the 
     * source node.</dd>
     * <dt>TEXT_NODE, CDATA_SECTION_NODE, COMMENT_NODE</dt>
     * <dd>These three 
     * types of nodes inheriting from <code>CharacterData</code> copy their 
     * <code>data</code> and <code>length</code> attributes from those of 
     * the source node.</dd>
     *  
     * @param importedNodeThe node to import.
     * @param deepIf <code>true</code>, recursively import the subtree under 
     *   the specified node; if <code>false</code>, import only the node 
     *   itself, as explained above. This has no effect on <code>Attr</code>
     *   , <code>EntityReference</code>, and <code>Notation</code> nodes.
     * @return The imported node that belongs to this <code>Document</code>.
     * @exception DOMException
     *   NOT_SUPPORTED_ERR: Raised if the type of node being imported is not 
     *   supported.
     * @since DOM Level 2
     */
    public Node importNode(Node importedNode, 
                           boolean deep)
                           throws DOMException;

    /**
     * Creates an element of the given qualified name and namespace URI. 
     * HTML-only DOM implementations do not need to implement this method.
     * @param namespaceURIThe namespace URI of the element to create.
     * @param qualifiedNameThe qualified name of the element type to 
     *   instantiate.
     * @return A new <code>Element</code> object with the following 
     *   attributes:AttributeValue<code>Node.nodeName</code>
     *   <code>qualifiedName</code><code>Node.namespaceURI</code>
     *   <code>namespaceURI</code><code>Node.prefix</code>prefix, extracted 
     *   from <code>qualifiedName</code>, or <code>null</code> if there is 
     *   no prefix<code>Node.localName</code>local name, extracted from 
     *   <code>qualifiedName</code><code>Element.tagName</code>
     *   <code>qualifiedName</code>
     * @exception DOMException
     *   INVALID_CHARACTER_ERR: Raised if the specified qualified name 
     *   contains an illegal character.
     *   <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> has a prefix that is "xml" and the 
     *   <code>namespaceURI</code> is different from "
     *   http://www.w3.org/XML/1998/namespace" .
     * @since DOM Level 2
     */
    public Element createElementNS(String namespaceURI, 
                                   String qualifiedName)
                                   throws DOMException;

    /**
     * Creates an attribute of the given qualified name and namespace URI. 
     * HTML-only DOM implementations do not need to implement this method.
     * @param namespaceURIThe namespace URI of the attribute to create.
     * @param qualifiedNameThe qualified name of the attribute to instantiate.
     * @return A new <code>Attr</code> object with the following attributes:
     *   AttributeValue<code>Node.nodeName</code>qualifiedName
     *   <code>Node.namespaceURI</code><code>namespaceURI</code>
     *   <code>Node.prefix</code>prefix, extracted from 
     *   <code>qualifiedName</code>, or <code>null</code> if there is no 
     *   prefix<code>Node.localName</code>local name, extracted from 
     *   <code>qualifiedName</code><code>Attr.name</code>
     *   <code>qualifiedName</code><code>Node.nodeValue</code>the empty 
     *   string
     * @exception DOMException
     *   INVALID_CHARACTER_ERR: Raised if the specified qualified name 
     *   contains an illegal character.
     *   <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>, if the 
     *   <code>qualifiedName</code> has a prefix that is "xml" and the 
     *   <code>namespaceURI</code> is different from "
     *   http://www.w3.org/XML/1998/namespace", or if the 
     *   <code>qualifiedName</code> is "xmlns" and the 
     *   <code>namespaceURI</code> is different from "
     *   http://www.w3.org/2000/xmlns/".
     * @since DOM Level 2
     */
    public Attr createAttributeNS(String namespaceURI, 
                                  String qualifiedName)
                                  throws DOMException;

    /**
     * Returns a <code>NodeList</code> of all the <code>Elements</code> with a 
     * given local name and namespace URI in the order in which they are 
     * encountered in a preorder traversal of the <code>Document</code> tree.
     * @param namespaceURIThe namespace URI of the elements to match on. The 
     *   special value "*" matches all namespaces.
     * @param localNameThe local name of the elements to match on. The 
     *   special value "*" matches all local names.
     * @return A new <code>NodeList</code> object containing all the matched 
     *   <code>Elements</code>.
     * @since DOM Level 2
     */
    public NodeList getElementsByTagNameNS(String namespaceURI, 
                                           String localName);

    /**
     * Returns the <code>Element</code> whose <code>ID</code> is given by 
     * <code>elementId</code>. If no such element exists, returns 
     * <code>null</code>. Behavior is not defined if more than one element 
     * has this <code>ID</code>. The DOM implementation must have 
     * information that says which attributes are of type ID. Attributes 
     * with the name "ID" are not of type ID unless so defined. 
     * Implementations that do not know whether attributes are of type ID or 
     * not are expected to return <code>null</code>.
     * @param elementIdThe unique <code>id</code> value for an element.
     * @return The matching element.
     * @since DOM Level 2
     */
    public Element getElementById(String elementId);

}