/*
 * 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>Node</code> interface is the primary datatype for the entire 
 * Document Object Model. It represents a single node in the document tree. 
 * While all objects implementing the <code>Node</code> interface expose 
 * methods for dealing with children, not all objects implementing the 
 * <code>Node</code> interface may have children. For example, 
 * <code>Text</code> nodes may not have children, and adding children to 
 * such nodes results in a <code>DOMException</code> being raised.
 * <p>The attributes <code>nodeName</code>, <code>nodeValue</code> and 
 * <code>attributes</code> are included as a mechanism to get at node 
 * information without casting down to the specific derived interface. In 
 * cases where there is no obvious mapping of these attributes for a 
 * specific <code>nodeType</code> (e.g., <code>nodeValue</code> for an 
 * <code>Element</code> or <code>attributes</code> for a <code>Comment</code>
 * ), this returns <code>null</code>. Note that the specialized interfaces 
 * may contain additional and more convenient mechanisms to get and set the 
 * relevant information.
 * <p>The values of <code>nodeName</code>, 
 * <code>nodeValue</code>, and <code>attributes</code> vary according to the 
 * node type as follows: 
 * <table border='1' summary="Describes interface, node name, node value, and attributes">
 * <tr>
 * <th>Interface</th>
 * <th>nodeName</th>
 * <th>nodeValue</th>
 * <th>attributes</th>
 * </tr>
 * <tr>
 * <td valign='top'>Attr</td>
 * <td valign='top'>name of 
 * attribute</td>
 * <td valign='top'>value of attribute</td>
 * <td valign='top'>null</td>
 * </tr>
 * <tr>
 * <td valign='top'>CDATASection</td>
 * <td valign='top'><code>"#cdata-section"</code></td>
 * <td valign='top'>
 * content of the CDATA Section</td>
 * <td valign='top'>null</td>
 * </tr>
 * <tr>
 * <td valign='top'>Comment</td>
 * <td valign='top'><code>"#comment"</code></td>
 * <td valign='top'>content of 
 * the comment</td>
 * <td valign='top'>null</td>
 * </tr>
 * <tr>
 * <td valign='top'>Document</td>
 * <td valign='top'><code>"#document"</code></td>
 * <td valign='top'>null</td>
 * <td valign='top'>null</td>
 * </tr>
 * <tr>
 * <td valign='top'>DocumentFragment</td>
 * <td valign='top'>
 * <code>"#document-fragment"</code></td>
 * <td valign='top'>null</td>
 * <td valign='top'>null</td>
 * </tr>
 * <tr>
 * <td valign='top'>DocumentType</td>
 * <td valign='top'>document type name</td>
 * <td valign='top'>
 * null</td>
 * <td valign='top'>null</td>
 * </tr>
 * <tr>
 * <td valign='top'>Element</td>
 * <td valign='top'>tag name</td>
 * <td valign='top'>null</td>
 * <td valign='top'>NamedNodeMap</td>
 * </tr>
 * <tr>
 * <td valign='top'>Entity</td>
 * <td valign='top'>entity name</td>
 * <td valign='top'>null</td>
 * <td valign='top'>null</td>
 * </tr>
 * <tr>
 * <td valign='top'>
 * EntityReference</td>
 * <td valign='top'>name of entity referenced</td>
 * <td valign='top'>null</td>
 * <td valign='top'>null</td>
 * </tr>
 * <tr>
 * <td valign='top'>Notation</td>
 * <td valign='top'>notation name</td>
 * <td valign='top'>null</td>
 * <td valign='top'>
 * null</td>
 * </tr>
 * <tr>
 * <td valign='top'>ProcessingInstruction</td>
 * <td valign='top'>target</td>
 * <td valign='top'>entire content excluding the target</td>
 * <td valign='top'>null</td>
 * </tr>
 * <tr>
 * <td valign='top'>Text</td>
 * <td valign='top'>
 * <code>"#text"</code></td>
 * <td valign='top'>content of the text node</td>
 * <td valign='top'>null</td>
 * </tr>
 * </table> 
 * <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 Node {
    // NodeType
    /**
     * The node is an <code>Element</code>.
     */
    public static final short ELEMENT_NODE              = 1;
    /**
     * The node is an <code>Attr</code>.
     */
    public static final short ATTRIBUTE_NODE            = 2;
    /**
     * The node is a <code>Text</code> node.
     */
    public static final short TEXT_NODE                 = 3;
    /**
     * The node is a <code>CDATASection</code>.
     */
    public static final short CDATA_SECTION_NODE        = 4;
    /**
     * The node is an <code>EntityReference</code>.
     */
    public static final short ENTITY_REFERENCE_NODE     = 5;
    /**
     * The node is an <code>Entity</code>.
     */
    public static final short ENTITY_NODE               = 6;
    /**
     * The node is a <code>ProcessingInstruction</code>.
     */
    public static final short PROCESSING_INSTRUCTION_NODE = 7;
    /**
     * The node is a <code>Comment</code>.
     */
    public static final short COMMENT_NODE              = 8;
    /**
     * The node is a <code>Document</code>.
     */
    public static final short DOCUMENT_NODE             = 9;
    /**
     * The node is a <code>DocumentType</code>.
     */
    public static final short DOCUMENT_TYPE_NODE        = 10;
    /**
     * The node is a <code>DocumentFragment</code>.
     */
    public static final short DOCUMENT_FRAGMENT_NODE    = 11;
    /**
     * The node is a <code>Notation</code>.
     */
    public static final short NOTATION_NODE             = 12;

    /**
     * The name of this node, depending on its type; see the table above.
     */
    public String getNodeName();

    /**
     * The value of this node, depending on its type; see the table above. 
     * When it is defined to be <code>null</code>, setting it has no effect.
     * @exception DOMException
     *   NO_MODIFICATION_ALLOWED_ERR: Raised when the node is readonly.
     * @exception DOMException
     *   DOMSTRING_SIZE_ERR: Raised when it would return more characters than 
     *   fit in a <code>DOMString</code> variable on the implementation 
     *   platform.
     */
    public String getNodeValue()
                                 throws DOMException;
    /**
     * The value of this node, depending on its type; see the table above. 
     * When it is defined to be <code>null</code>, setting it has no effect.
     * @exception DOMException
     *   NO_MODIFICATION_ALLOWED_ERR: Raised when the node is readonly.
     * @exception DOMException
     *   DOMSTRING_SIZE_ERR: Raised when it would return more characters than 
     *   fit in a <code>DOMString</code> variable on the implementation 
     *   platform.
     */
    public void setNodeValue(String nodeValue)
                                 throws DOMException;

    /**
     * A code representing the type of the underlying object, as defined above.
     */
    public short getNodeType();

    /**
     * The parent of this node. All nodes, except <code>Attr</code>, 
     * <code>Document</code>, <code>DocumentFragment</code>, 
     * <code>Entity</code>, and <code>Notation</code> may have a parent. 
     * However, if a node has just been created and not yet added to the 
     * tree, or if it has been removed from the tree, this is 
     * <code>null</code>.
     */
    public Node getParentNode();

    /**
     * A <code>NodeList</code> that contains all children of this node. If 
     * there are no children, this is a <code>NodeList</code> containing no 
     * nodes.
     */
    public NodeList getChildNodes();

    /**
     * The first child of this node. If there is no such node, this returns 
     * <code>null</code>.
     */
    public Node getFirstChild();

    /**
     * The last child of this node. If there is no such node, this returns 
     * <code>null</code>.
     */
    public Node getLastChild();

    /**
     * The node immediately preceding this node. If there is no such node, 
     * this returns <code>null</code>.
     */
    public Node getPreviousSibling();

    /**
     * The node immediately following this node. If there is no such node, 
     * this returns <code>null</code>.
     */
    public Node getNextSibling();

    /**
     * A <code>NamedNodeMap</code> containing the attributes of this node (if 
     * it is an <code>Element</code>) or <code>null</code> otherwise.
     */
    public NamedNodeMap getAttributes();

    /**
     * The <code>Document</code> object associated with this node. This is 
     * also the <code>Document</code> object used to create new nodes. When 
     * this node is a <code>Document</code> or a <code>DocumentType</code> 
     * which is not used with any <code>Document</code> yet, this is 
     * <code>null</code>.
     * @version DOM Level 2
     */
    public Document getOwnerDocument();

    /**
     * Inserts the node <code>newChild</code> before the existing child node 
     * <code>refChild</code>. If <code>refChild</code> is <code>null</code>, 
     * insert <code>newChild</code> at the end of the list of children.
     * <br>If <code>newChild</code> is a <code>DocumentFragment</code> object, 
     * all of its children are inserted, in the same order, before 
     * <code>refChild</code>. If the <code>newChild</code> is already in the 
     * tree, it is first removed.
     * @param newChild The node to insert.
     * @param refChild The reference node, i.e., the node before which the 
     *   new node must be inserted.
     * @return The node being inserted.
     * @exception DOMException
     *   HIERARCHY_REQUEST_ERR: Raised if this node is of a type that does not 
     *   allow children of the type of the <code>newChild</code> node, or if 
     *   the node to insert is one of this node's ancestors or this node 
     *   itself.
     *   <br>WRONG_DOCUMENT_ERR: Raised if <code>newChild</code> was created 
     *   from a different document than the one that created this node.
     *   <br>NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly or 
     *   if the parent of the node being inserted is readonly.
     *   <br>NOT_FOUND_ERR: Raised if <code>refChild</code> is not a child of 
     *   this node.
     */
    public Node insertBefore(Node newChild, 
                             Node refChild)
                             throws DOMException;

    /**
     * Replaces the child node <code>oldChild</code> with <code>newChild</code>
     *  in the list of children, and returns the <code>oldChild</code> node.
     * <br>If <code>newChild</code> is a <code>DocumentFragment</code> object, 
     * <code>oldChild</code> is replaced by all of the 
     * <code>DocumentFragment</code> children, which are inserted in the 
     * same order. If the <code>newChild</code> is already in the tree, it 
     * is first removed.
     * @param newChild The new node to put in the child list.
     * @param oldChild The node being replaced in the list.
     * @return The node replaced.
     * @exception DOMException
     *   HIERARCHY_REQUEST_ERR: Raised if this node is of a type that does not 
     *   allow children of the type of the <code>newChild</code> node, or if 
     *   the node to put in is one of this node's ancestors or this node 
     *   itself.
     *   <br>WRONG_DOCUMENT_ERR: Raised if <code>newChild</code> was created 
     *   from a different document than the one that created this node.
     *   <br>NO_MODIFICATION_ALLOWED_ERR: Raised if this node or the parent of 
     *   the new node is readonly.
     *   <br>NOT_FOUND_ERR: Raised if <code>oldChild</code> is not a child of 
     *   this node.
     */
    public Node replaceChild(Node newChild, 
                             Node oldChild)
                             throws DOMException;

    /**
     * Removes the child node indicated by <code>oldChild</code> from the list 
     * of children, and returns it.
     * @param oldChild The node being removed.
     * @return The node removed.
     * @exception DOMException
     *   NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
     *   <br>NOT_FOUND_ERR: Raised if <code>oldChild</code> is not a child of 
     *   this node.
     */
    public Node removeChild(Node oldChild)
                            throws DOMException;

    /**
     * Adds the node <code>newChild</code> to the end of the list of children 
     * of this node. If the <code>newChild</code> is already in the tree, it 
     * is first removed.
     * @param newChild The node to add.If it is a 
     *   <code>DocumentFragment</code> object, the entire contents of the 
     *   document fragment are moved into the child list of this node
     * @return The node added.
     * @exception DOMException
     *   HIERARCHY_REQUEST_ERR: Raised if this node is of a type that does not 
     *   allow children of the type of the <code>newChild</code> node, or if 
     *   the node to append is one of this node's ancestors or this node 
     *   itself.
     *   <br>WRONG_DOCUMENT_ERR: Raised if <code>newChild</code> was created 
     *   from a different document than the one that created this node.
     *   <br>NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly or 
     *   if the previous parent of the node being inserted is readonly.
     */
    public Node appendChild(Node newChild)
                            throws DOMException;

    /**
     * Returns whether this node has any children.
     * @return <code>true</code> if this node has any children, 
     *   <code>false</code> otherwise.
     */
    public boolean hasChildNodes();

    /**
     * Returns a duplicate of this node, i.e., serves as a generic copy 
     * constructor for nodes. The duplicate node has no parent; (
     * <code>parentNode</code> is <code>null</code>.).
     * <br>Cloning an <code>Element</code> copies all attributes and their 
     * values, including those generated by the XML processor to represent 
     * defaulted attributes, but this method does not copy any text it 
     * contains unless it is a deep clone, since the text is contained in a 
     * child <code>Text</code> node. Cloning an <code>Attribute</code> 
     * directly, as opposed to be cloned as part of an <code>Element</code> 
     * cloning operation, returns a specified attribute (
     * <code>specified</code> is <code>true</code>). Cloning any other type 
     * of node simply returns a copy of this node.
     * <br>Note that cloning an immutable subtree results in a mutable copy, 
     * but the children of an <code>EntityReference</code> clone are readonly
     * . In addition, clones of unspecified <code>Attr</code> nodes are 
     * specified. And, cloning <code>Document</code>, 
     * <code>DocumentType</code>, <code>Entity</code>, and 
     * <code>Notation</code> nodes is implementation dependent.
     * @param deep If <code>true</code>, recursively clone the subtree under 
     *   the specified node; if <code>false</code>, clone only the node 
     *   itself (and its attributes, if it is an <code>Element</code>).
     * @return The duplicate node.
     */
    public Node cloneNode(boolean deep);

    /**
     * Puts all <code>Text</code> nodes in the full depth of the sub-tree 
     * underneath this <code>Node</code>, including attribute nodes, into a 
     * "normal" form where only structure (e.g., elements, comments, 
     * processing instructions, CDATA sections, and entity references) 
     * separates <code>Text</code> nodes, i.e., there are neither adjacent 
     * <code>Text</code> nodes nor empty <code>Text</code> nodes. This can 
     * be used to ensure that the DOM view of a document is the same as if 
     * it were saved and re-loaded, and is useful when operations (such as 
     * XPointer  lookups) that depend on a particular document tree 
     * structure are to be used.In cases where the document contains 
     * <code>CDATASections</code>, the normalize operation alone may not be 
     * sufficient, since XPointers do not differentiate between 
     * <code>Text</code> nodes and <code>CDATASection</code> nodes.
     * @version DOM Level 2
     */
    public void normalize();

    /**
     * Tests whether the DOM implementation implements a specific feature and 
     * that feature is supported by this node.
     * @param feature The name of the feature to test. This is the same name 
     *   which can be passed to the method <code>hasFeature</code> on 
     *   <code>DOMImplementation</code>.
     * @param version This is the version number of the feature to test. In 
     *   Level 2, version 1, this is the string "2.0". If the version is not 
     *   specified, supporting any version of the feature will cause the 
     *   method to return <code>true</code>.
     * @return Returns <code>true</code> if the specified feature is 
     *   supported on this node, <code>false</code> otherwise.
     * @since DOM Level 2
     */
    public boolean isSupported(String feature, 
                               String version);

    /**
     * The namespace URI of this node, or <code>null</code> if it is 
     * unspecified.
     * <br>This is not a computed value that is the result of a namespace 
     * lookup based on an examination of the namespace declarations in 
     * scope. It is merely the namespace URI given at creation time.
     * <br>For nodes of any type other than <code>ELEMENT_NODE</code> and 
     * <code>ATTRIBUTE_NODE</code> and nodes created with a DOM Level 1 
     * method, such as <code>createElement</code> from the 
     * <code>Document</code> interface, this is always <code>null</code>.Per 
     * the Namespaces in XML Specification  an attribute does not inherit 
     * its namespace from the element it is attached to. If an attribute is 
     * not explicitly given a namespace, it simply has no namespace.
     * @since DOM Level 2
     */
    public String getNamespaceURI();

    /**
     * The namespace prefix of this node, or <code>null</code> if it is 
     * unspecified.
     * <br>Note that setting this attribute, when permitted, changes the 
     * <code>nodeName</code> attribute, which holds the qualified name, as 
     * well as the <code>tagName</code> and <code>name</code> attributes of 
     * the <code>Element</code> and <code>Attr</code> interfaces, when 
     * applicable.
     * <br>Note also that changing the prefix of an attribute that is known to 
     * have a default value, does not make a new attribute with the default 
     * value and the original prefix appear, since the 
     * <code>namespaceURI</code> and <code>localName</code> do not change.
     * <br>For nodes of any type other than <code>ELEMENT_NODE</code> and 
     * <code>ATTRIBUTE_NODE</code> and nodes created with a DOM Level 1 
     * method, such as <code>createElement</code> from the 
     * <code>Document</code> interface, this is always <code>null</code>.
     * @exception DOMException
     *   INVALID_CHARACTER_ERR: Raised if the specified prefix contains an 
     *   illegal character, per the XML 1.0 specification .
     *   <br>NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
     *   <br>NAMESPACE_ERR: Raised if the specified <code>prefix</code> is 
     *   malformed per the Namespaces in XML specification, if the 
     *   <code>namespaceURI</code> of this node is <code>null</code>, if the 
     *   specified prefix is "xml" and the <code>namespaceURI</code> of this 
     *   node is different from "http://www.w3.org/XML/1998/namespace", if 
     *   this node is an attribute and the specified prefix is "xmlns" and 
     *   the <code>namespaceURI</code> of this node is different from "
     *   http://www.w3.org/2000/xmlns/", or if this node is an attribute and 
     *   the <code>qualifiedName</code> of this node is "xmlns" .
     * @since DOM Level 2
     */
    public String getPrefix();
    /**
     * The namespace prefix of this node, or <code>null</code> if it is 
     * unspecified.
     * <br>Note that setting this attribute, when permitted, changes the 
     * <code>nodeName</code> attribute, which holds the qualified name, as 
     * well as the <code>tagName</code> and <code>name</code> attributes of 
     * the <code>Element</code> and <code>Attr</code> interfaces, when 
     * applicable.
     * <br>Note also that changing the prefix of an attribute that is known to 
     * have a default value, does not make a new attribute with the default 
     * value and the original prefix appear, since the 
     * <code>namespaceURI</code> and <code>localName</code> do not change.
     * <br>For nodes of any type other than <code>ELEMENT_NODE</code> and 
     * <code>ATTRIBUTE_NODE</code> and nodes created with a DOM Level 1 
     * method, such as <code>createElement</code> from the 
     * <code>Document</code> interface, this is always <code>null</code>.
     * @exception DOMException
     *   INVALID_CHARACTER_ERR: Raised if the specified prefix contains an 
     *   illegal character, per the XML 1.0 specification .
     *   <br>NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
     *   <br>NAMESPACE_ERR: Raised if the specified <code>prefix</code> is 
     *   malformed per the Namespaces in XML specification, if the 
     *   <code>namespaceURI</code> of this node is <code>null</code>, if the 
     *   specified prefix is "xml" and the <code>namespaceURI</code> of this 
     *   node is different from "http://www.w3.org/XML/1998/namespace", if 
     *   this node is an attribute and the specified prefix is "xmlns" and 
     *   the <code>namespaceURI</code> of this node is different from "
     *   http://www.w3.org/2000/xmlns/", or if this node is an attribute and 
     *   the <code>qualifiedName</code> of this node is "xmlns" .
     * @since DOM Level 2
     */
    public void setPrefix(String prefix)
                               throws DOMException;

    /**
     * Returns the local part of the qualified name of this node.
     * <br>For nodes of any type other than <code>ELEMENT_NODE</code> and 
     * <code>ATTRIBUTE_NODE</code> and nodes created with a DOM Level 1 
     * method, such as <code>createElement</code> from the 
     * <code>Document</code> interface, this is always <code>null</code>.
     * @since DOM Level 2
     */
    public String getLocalName();

    /**
     * Returns whether this node (if it is an element) has any attributes.
     * @return <code>true</code> if this node has any attributes, 
     *   <code>false</code> otherwise.
     * @since DOM Level 2
     */
    public boolean hasAttributes();

}