/*

 * 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: DOM_Element.hpp 568078 2007-08-21 11:43:25Z amassari $

 */

#ifndef DOM_Element_HEADER_GUARD_

#define DOM_Element_HEADER_GUARD_

#include <xercesc/util/XercesDefs.hpp>

#include "DOM_Node.hpp"

XERCES_CPP_NAMESPACE_BEGIN

class DOM_Attr;

class DOM_NodeList;

class ElementImpl;

/**

 * By far the vast majority of objects (apart from text) that authors

 * encounter when traversing a document are <code>DOM_Element</code> nodes.

 *

 * Assume the following XML document:<elementExample id="demo">

 * <subelement1/>

 * <subelement2><subsubelement/></subelement2>

 * </elementExample>

 * <p>When represented using DOM, the top node is an <code>DOM_Element</code> node

 * for "elementExample", which contains two child <code>DOM_Element</code> nodes,

 * one for "subelement1" and one for "subelement2". "subelement1" contains no

 * child nodes.

 * <p>Elements may have attributes associated with them; since the

 * <code>DOM_Element</code> interface inherits from <code>DOM_Node</code>, the generic

 *  <code>DOM_Node</code> interface method <code>getAttributes</code> may be used

 * to retrieve the set of all attributes for an element.  There are methods on

 *  the <code>DOM_Element</code> interface to retrieve either an <code>DOM_Attr</code>

 *  object by name or an attribute value by name. In XML, where an attribute

 * value may contain entity references, an <code>DOM_Attr</code> object should be

 * retrieved to examine the possibly fairly complex sub-tree representing the

 * attribute value. On the other hand, in HTML, where all attributes have

 * simple string values, methods to directly access an attribute value can

 * safely be used as a convenience.

 */

class DEPRECATED_DOM_EXPORT DOM_Element: public DOM_Node {

private:

public:

    /** @name Constructors and assignment operator */

    //@{

    /**

    * Default constructor for DOM_Element.  The resulting object does not

    * refer to an actual Element node; it will compare == to 0, and is similar

    * to a null object reference variable in Java.  It may subsequently be

    * assigned to refer to an actual Element node.

    * <p>

    * New comment nodes are created by DOM_Document::createElement().

      *

      */

    DOM_Element();

    /**

      * Copy constructor.  Creates a new <code>DOM_Element</code> that refers to the

      * same underlying actual element as the original.

      *

      * @param other The object to be copied

      */

    DOM_Element(const DOM_Element &other);

    /**

      * Assignment operator.

      *

      * @param other The object to be copied.

      */

    DOM_Element & operator = (const DOM_Element &other);

    /**

      * Assignment operator.  This overloaded variant is provided for

      *   the sole purpose of setting a DOM_Node reference variable to

      *   zero.  Nulling out a reference variable in this way will decrement

      *   the reference count on the underlying Node object that the variable

      *   formerly referenced.  This effect is normally obtained when reference

      *   variable goes out of scope, but zeroing them can be useful for

      *   global instances, or for local instances that will remain in scope

      *   for an extended time,  when the storage belonging to the underlying

      *   node needs to be reclaimed.

      *

      * @param val   Only a value of 0, or null, is allowed.

      */

    DOM_Element & operator = (const DOM_NullPtr *val);

    //@}

    /** @name Destructor. */

    //@{

	 /**

      * Destructor.  The object being destroyed is the reference

      * object, not the underlying Element itself.

	  *

	  */

    ~DOM_Element();

    //@}

    /** @name Getter functions. */

    //@{

  /**

   * The name of the element.

   *

   * For example, in: <elementExample

   * id="demo"&gt;  ... &lt;/elementExample&gt; , <code>tagName</code> has

   * the value <code>"elementExample"</code>. Note that this is

   * case-preserving in XML, as are all of the operations of the DOM.

   */

  DOMString         getTagName() const;

  /**

   * Retrieves an attribute value by name.

   *

   * @param name The name of the attribute to retrieve.

   * @return The <code>DOM_Attr</code> value as a string, or the empty  string if

   *   that attribute does not have a specified or default value.

   */

  DOMString         getAttribute(const DOMString &name) const;

  /**

   * Retrieves an <code>DOM_Attr</code> node by name.

   *

   * @param name The name (<CODE>nodeName</CODE>) of the attribute to retrieve.

   * @return The <code>DOM_Attr</code> node with the specified name (<CODE>nodeName</CODE>) or

   *   <code>null</code> if there is no such attribute.

   */

  DOM_Attr        getAttributeNode(const DOMString &name) const;

  /**

   * Returns a <code>NodeList</code> of all descendant elements with a given

   * tag name, in the order in which they would be encountered in a preorder

   * traversal of the <code>DOM_Element</code> tree.

   *

   * @param name The name of the tag to match on. The special value "*"

   *   matches all tags.

   * @return A list of matching <code>DOM_Element</code> nodes.

   */

  DOM_NodeList    getElementsByTagName(const DOMString &name) const;

  //@}

  /** @name Set functions. */

  //@{

  /**

   * Adds a new attribute.

   *

   * If an attribute with that name is already present

   * in the element, its value is changed to be that of the value parameter.

   * This value is a simple string, it is not parsed as it is being set. So

   * any markup (such as syntax to be recognized as an entity reference) is

   * treated as literal text, and needs to be appropriately escaped by the

   * implementation when it is written out. In order to assign an attribute

   * value that contains entity references, the user must create an

   * <code>DOM_Attr</code> node plus any <code>Text</code> and

   * <code>EntityReference</code> nodes, build the appropriate subtree, and

   * use <code>setAttributeNode</code> to assign it as the value of an

   * attribute.

   * @param name The name of the attribute to create or alter.

   * @param value Value to set in string form.

   * @exception DOMException

   *   INVALID_CHARACTER_ERR: Raised if the specified name contains an

   *   illegal character.

   *   <br>NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.

   */

   void             setAttribute(const DOMString &name,

                                 const DOMString &value);

   /**

    * Adds a new attribute.

    *

    * If an attribute with that name (<CODE>nodeName</CODE>) is already present

    * in the element, it is replaced by the new one.

    * @param newAttr The <code>DOM_Attr</code> node to add to the attribute list.

    * @return If the <code>newAttr</code> attribute replaces an existing

    *   attribute, the replaced

    *   <code>DOM_Attr</code> node is returned, otherwise <code>null</code> is

    *   returned.

    * @exception DOMException

    *   WRONG_DOCUMENT_ERR: Raised if <code>newAttr</code> was created from a

    *   different document than the one that created the element.

    *   <br>NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.

    *   <br>INUSE_ATTRIBUTE_ERR: Raised if <code>newAttr</code> is already an

    *   attribute of another <code>DOM_Element</code> object. The DOM user must

    *   explicitly clone <code>DOM_Attr</code> nodes to re-use them in other

    *   elements.

    */

   DOM_Attr        setAttributeNode(DOM_Attr newAttr);

   //@}

   /** @name Functions which modify the Element. */

   //@{

  /**

   * Removes the specified attribute node.

   * If the removed <CODE>DOM_Attr</CODE>

   *   has a default value it is immediately replaced. The replacing attribute

   *   has the same namespace URI and local name, as well as the original prefix,

   *   when applicable.

   *

   * @param oldAttr The <code>DOM_Attr</code> node to remove from the attribute

   *   list.

   * @return The <code>DOM_Attr</code> node that was removed.

   * @exception DOMException

   *   NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.

   *   <br>NOT_FOUND_ERR: Raised if <code>oldAttr</code> is not an attribute

   *   of the element.

   */

  DOM_Attr        removeAttributeNode(DOM_Attr oldAttr);

  /**

   * Removes an attribute by name.

   *

   * If the removed attribute

   *   is known to have a default value, an attribute immediately appears

   *   containing the default value as well as the corresponding namespace URI,

   *   local name, and prefix when applicable.<BR>To remove an attribute by local

   *   name and namespace URI, use the <CODE>removeAttributeNS</CODE> method.

   * @param name The name of the attribute to remove.

   * @exception DOMException

   *   NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.

   */

  void              removeAttribute(const DOMString &name);

  //@}

  /** @name Functions introduced in DOM Level 2. */

  //@{

  /**

   * Retrieves an attribute value by local name and namespace URI.

   *

   * @param namespaceURI The <em>namespace URI</em> of

   *    the attribute to retrieve.

   * @param localName The <em>local name</em> of the

   *    attribute to retrieve.

   * @return The <code>DOM_Attr</code> value as a string, or an <CODE>null</CODE> if

   *    that attribute does not have a specified or default value.

   */

  DOMString         getAttributeNS(const DOMString &namespaceURI,

	const DOMString &localName) const;

  /**

   * Adds a new attribute. If an attribute with the same

   * local name and namespace URI is already present on the element, its prefix

   * is changed to be the prefix part of the <CODE>qualifiedName</CODE>, and

   * its value is changed to be the <CODE>value</CODE> parameter. This value is

   * a simple string, it is not parsed as it is being set. So any markup (such

   * as syntax to be recognized as an entity reference) is treated as literal

   * text, and needs to be appropriately escaped by the implementation when it

   * is written out. In order to assign an attribute value that contains entity

   * references, the user must create an <CODE>DOM_Attr</CODE>

   * node plus any <CODE>DOM_Text</CODE> and <CODE>DOM_EntityReference</CODE>

   * nodes, build the appropriate subtree, and use

   * <CODE>setAttributeNodeNS</CODE> or <CODE>setAttributeNode</CODE> to assign

   * it as the value of an attribute.

   *

   * @param namespaceURI The <em>namespace URI</em> of

   *    the attribute to create or alter.

   * @param qualifiedName The <em>qualified name</em> of the

   *    attribute to create or alter.

   * @param value The value to set in string form.

   * @exception DOMException

   *   INVALID_CHARACTER_ERR: Raised if the specified qualified name contains an

   *   illegal character.

   *   <br>NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.

   * <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 an empty string,

   *        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", if the

   *        <CODE>qualifiedName</CODE> has a prefix that is "xmlns" and the

   *        <CODE>namespaceURI</CODE> is different from

   *        "http://www.w3.org/2000/xmlns/", or if the

   *        <CODE>qualifiedName</CODE> is "xmlns" and the

   *        <CODE>namespaceURI</CODE> is different from

   *        "http://www.w3.org/2000/xmlns/".

   */

   void             setAttributeNS(const DOMString &namespaceURI,

	const DOMString &qualifiedName, const DOMString &value);

  /**

   * Removes an attribute by local name and namespace URI. If the

   * removed attribute has a default value it is immediately replaced.

   * The replacing attribute has the same namespace URI and local name, as well as

   * the original prefix.

   *

   * @param namespaceURI The <em>namespace URI</em> of

   *    the attribute to remove.

   * @param localName The <em>local name</em> of the

   *    attribute to remove.

   * @exception DOMException

   *   NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.

   */

  void              removeAttributeNS(const DOMString &namespaceURI,

	const DOMString &localName);

  /**

   * Retrieves an <code>DOM_Attr</code> node by local name and namespace URI.

   *

   * @param namespaceURI The <em>namespace URI</em> of

   *    the attribute to retrieve.

   * @param localName The <em>local name</em> of the

   *    attribute to retrieve.

   * @return The <code>DOM_Attr</code> node with the specified attribute local

   *    name and namespace URI or <code>null</code> if there is no such attribute.

   */

  DOM_Attr        getAttributeNodeNS(const DOMString &namespaceURI,

	const DOMString &localName) const;

   /**

    * Adds a new attribute.

    *

    * If an attribute with that local name and namespace URI is already present

    * in the element, it is replaced by the new one.

    *

    * @param newAttr The <code>DOM_Attr</code> node to add to the attribute list.

    * @return If the <code>newAttr</code> attribute replaces an existing

    *    attribute with the same <em>local name</em> and <em>namespace URI</em>,

    *    the replaced <code>DOM_Attr</code> node is

    *    returned, otherwise <code>null</code> is returned.

    * @exception DOMException

    *   WRONG_DOCUMENT_ERR: Raised if <code>newAttr</code> was created from a

    *   different document than the one that created the element.

    *   <br>NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.

    *   <br>INUSE_ATTRIBUTE_ERR: Raised if <code>newAttr</code> is already an

    *   attribute of another <code>DOM_Element</code> object. The DOM user must

    *   explicitly clone <code>DOM_Attr</code> nodes to re-use them in other

    *   elements.

    */

   DOM_Attr        setAttributeNodeNS(DOM_Attr newAttr);

  /**

   * Returns a <code>DOM_NodeList</code> of all the <code>DOM_Element</code>s

   * with a given local name and namespace URI in the order in which they

   * would be encountered in a preorder traversal of the

   * <code>DOM_Document</code> tree, starting from this node.

   *

   * @param namespaceURI The <em>namespace URI</em> of

   *    the elements to match on. The special value "*" matches all

   *    namespaces.

   * @param localName The <em>local name</em> of the

   *    elements to match on. The special value "*" matches all local names.

   * @return A new <code>DOM_NodeList</code> object containing all the matched

   *    <code>DOM_Element</code>s.

   */

  DOM_NodeList    getElementsByTagNameNS(const DOMString &namespaceURI,

	const DOMString &localName) const;

    /**

     *  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.

     */

    bool         hasAttributes() const;

    /**

     * Returns <code>true</code> when an attribute with a given name is

     * specified on this element or has a default value, <code>false</code>

     * otherwise.

     * @param name The name of the attribute to look for.

     * @return <code>true</code> if an attribute with the given name is

     *   specified on this element or has a default value, <code>false</code>

     *    otherwise.

     */

    bool         hasAttribute(const DOMString &name) const;

    /**

     * Returns <code>true</code> when an attribute with a given local name and

     * namespace URI is specified on this element or has a default value,

     * <code>false</code> otherwise. HTML-only DOM implementations do not

     * need to implement this method.

     * @param namespaceURI The namespace URI of the attribute to look for.

     * @param localName The local name of the attribute to look for.

     * @return <code>true</code> if an attribute with the given local name

     *   and namespace URI is specified or has a default value on this

     *   element, <code>false</code> otherwise.

     * @since DOM Level 2

     */

    bool         hasAttributeNS(const DOMString &namespaceURI,

                                const DOMString &localName) const;

  //@}

  protected:

     DOM_Element(ElementImpl *impl);

     friend class DOM_Document;

     friend class DOM_Attr;

};

XERCES_CPP_NAMESPACE_END

#endif