//

// Element.h

//

// Library: XML

// Package: DOM

// Module:  DOM

//

// Definition of the DOM Element class.

//

// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.

// and Contributors.

//

// SPDX-License-Identifier: BSL-1.0

//

#ifndef DOM_Element_INCLUDED

#define DOM_Element_INCLUDED

#include "Poco/XML/XML.h"

#include "Poco/DOM/AbstractContainerNode.h"

#include "Poco/XML/Name.h"

namespace Poco {

namespace XML {

class Attr;

class NodeList;

class Document;

class XML_API Element: public AbstractContainerNode

  /// The Element interface represents an element in an XML document.

  /// Elements may have attributes associated with them; since the Element interface

  /// inherits from Node, the generic Node interface attribute attributes may

  /// be used to retrieve the set of all attributes for an element. There are

  /// methods on the Element interface to retrieve either an Attr object by name

  /// or an attribute value by name. In XML, where an attribute value may contain

  /// entity references, an Attr object should be retrieved to examine the possibly

  /// fairly complex sub-tree representing the attribute value.

{

public:

  const XMLString& tagName() const;

    /// Returns the name of the element.

    ///

    /// For example, in

    ///

    ///     <elementExample id="demo">

    ///         ...

    ///     </elementExample>

    ///

    /// tagName has the value "elementExample". Note that this is case-preserving in XML,

    /// as are all of the operations of the DOM.

  const XMLString& getAttribute(const XMLString& name) const;

    /// Retrieves an attribute value by name.

    ///

    /// Returns the attribute's value, if the attribute

    /// exists, or an empty string otherwise.

  void setAttribute(const XMLString& name, const XMLString& value);

    /// 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.

  void removeAttribute(const XMLString& name);

    /// Removes an attribute by name.

  Attr* getAttributeNode(const XMLString& name) const;

    /// Retrieves an Attr node by name.

  Attr* setAttributeNode(Attr* newAttr);

    /// Adds a new attribute. If an attribute with that name is already

    /// present in the element, it is replaced by the new one.

  Attr* addAttributeNodeNP(Attr* oldAttr, Attr* newAttr);

    /// For internal use only.

    /// Adds a new attribute after oldAttr.

    /// If oldAttr is 0, newAttr is set as first attribute.

    /// Returns newAttr.

    /// Does not fire any events.

  Attr* removeAttributeNode(Attr* oldAttr);

    /// Removes the specified attribute.

  NodeList* getElementsByTagName(const XMLString& name) const;

    /// Returns a NodeList of all descendant elements with a given tag

    /// name, in the order in which they would be encountered in a

    /// preorder traversal of the Element tree.

    ///

    /// The special name "*" matches all tags.

    ///

    /// The returned NodeList must be released with a call

    /// to release() when no longer needed.

  void normalize();

    /// Puts all Text nodes in the full depth of the sub-tree underneath this Element,

    /// including attribute nodes, into a "normal" form where only markup (e.g.,

    /// tags, comments, processing instructions, CDATA sections, and entity references)

    /// separates Text nodes, i.e., there are no adjacent Text 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.

    ///

    /// Note: In cases where the document contains CDATASections, the normalize

    /// operation alone may not be sufficient, since XPointers do not differentiate

    /// between Text nodes and CDATASection nodes.

  // DOM Level 2

  const XMLString& getAttributeNS(const XMLString& namespaceURI, const XMLString& localName) const;

    /// Retrieves an attribute value by name.

    ///

    /// Returns the attribute's value, if the attribute

    /// exists, or an empty string otherwise.

  void setAttributeNS(const XMLString& namespaceURI, const XMLString& qualifiedName, const XMLString& value);

    /// 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.

  void removeAttributeNS(const XMLString& namespaceURI, const XMLString& localName);

    /// Removes an attribute by name.

  Attr* getAttributeNodeNS(const XMLString& namespaceURI, const XMLString& localName) const;

    /// Retrieves an Attr node by name.

  Attr* setAttributeNodeNS(Attr* newAttr);

    /// Adds a new attribute. If an attribute with that name is already

    /// present in the element, it is replaced by the new one.

  bool hasAttribute(const XMLString& name) const;

    /// Returns true if and only if the element has the specified attribute.

  bool hasAttributeNS(const XMLString& namespaceURI, const XMLString& localName) const;

    /// Returns true if and only if the element has the specified attribute.

  NodeList* getElementsByTagNameNS(const XMLString& namespaceURI, const XMLString& localName) const;

    /// Returns a NodeList of all the descendant Elements with a given local name and namespace URI

    /// in the order in which they are encountered in a preorder traversal of this Element tree.

    ///

    /// The special value "*" matches all namespaces, or local names respectively.

    ///

    /// The returned NodeList must be released with a call

    /// to release() when no longer needed.

  const XMLString& namespaceURI() const;

  XMLString prefix() const;

  const XMLString& localName() const;

  bool hasAttributes() const;

  XMLString innerText() const;

  Element* getChildElement(const XMLString& name) const;

    /// Returns the first child element with the given name, or null

    /// if such an element does not exist.

    ///

    /// This method is an extension to the W3C Document Object Model.

  Element* getChildElementNS(const XMLString& namespaceURI, const XMLString& localName) const;

    /// Returns the first child element with the given namespaceURI and localName,

    /// or null if such an element does not exist.

    ///

    /// This method is an extension to the W3C Document Object Model.

  Element* getElementById(const XMLString& elementId, const XMLString& idAttribute) const;

    /// Returns the first Element whose ID attribute (given in idAttribute)

    /// has the given elementId. If no such element exists, returns null.

    ///

    /// This method is an extension to the W3C Document Object Model.

  Element* getElementByIdNS(const XMLString& elementId, const XMLString& idAttributeURI, const XMLString& idAttributeLocalName) const;

    /// Returns the first Element whose ID attribute (given in idAttributeURI and idAttributeLocalName)

    /// has the given elementId. If no such element exists, returns null.

    ///

    /// This method is an extension to the W3C Document Object Model.

  // Node

  const XMLString& nodeName() const;

  NamedNodeMap* attributes() const;

  unsigned short nodeType() const;

protected:

  Element(Document* pOwnerDocument, const XMLString& namespaceURI, const XMLString& localName, const XMLString& qname);

  Element(Document* pOwnerDocument, const Element& elem);

  ~Element();

  Node* copyNode(bool deep, Document* pOwnerDocument) const;

  void dispatchNodeRemovedFromDocument();

  void dispatchNodeInsertedIntoDocument();

private:

  const Name& _name;

  Attr*       _pFirstAttr;

  friend class Attr;

  friend class Document;

  friend class AttrMap;

};

//

// inlines

//

inline const XMLString& Element::tagName() const

{

  return _name.qname();

}

} } // namespace Poco::XML

#endif // DOM_Element_INCLUDED