source: XMLIO_V2/external/include/Poco/DOM/Attr.h @ 80

//
// Attr.h
//
// $Id: //poco/1.3/XML/include/Poco/DOM/Attr.h#1 $
//
// Library: XML
// Package: DOM
// Module:  DOM
//
// Definition of the DOM Attr class.
//
// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// Permission is hereby granted, free of charge, to any person or organization
// obtaining a copy of the software and accompanying documentation covered by
// this license (the "Software") to use, reproduce, display, distribute,
// execute, and transmit the Software, and to prepare derivative works of the
// Software, and to permit third-parties to whom the Software is furnished to
// do so, all subject to the following:
// 
// The copyright notices in the Software and this entire statement, including
// the above license grant, this restriction and the following disclaimer,
// must be included in all copies of the Software, in whole or in part, and
// all derivative works of the Software, unless such copies or derivative
// works are solely in the form of machine-executable object code generated by
// a source language processor.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
// SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
// FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
//


#ifndef DOM_Attr_INCLUDED
#define DOM_Attr_INCLUDED


#include "Poco/XML/XML.h"
#include "Poco/DOM/AbstractNode.h"
#include "Poco/DOM/Element.h"
#include "Poco/XML/Name.h"


namespace Poco {
namespace XML {


class XML_API Attr: public AbstractNode
        /// The Attr interface represents an attribute in an Element object. Typically
        /// the allowable values for the attribute are defined in a document type definition.
        /// 
        /// Attr objects inherit the Node interface, but since they are not actually
        /// child nodes of the element they describe, the DOM does not consider them
        /// part of the document tree. Thus, the Node attributes parentNode, previousSibling,
        /// and nextSibling have a null value for Attr objects. The DOM takes the view
        /// that attributes are properties of elements rather than having a separate
        /// identity from the elements they are associated with; this should make it
        /// more efficient to implement such features as default attributes associated
        /// with all elements of a given type. Furthermore, Attr nodes may not be immediate
        /// children of a DocumentFragment. However, they can be associated with Element
        /// nodes contained within a DocumentFragment. In short, users and implementors
        /// of the DOM need to be aware that Attr nodes have some things in common with
        /// other objects inheriting the Node interface, but they also are quite distinct.
        /// 
        /// The attribute's effective value is determined as follows: if this attribute
        /// has been explicitly assigned any value, that value is the attribute's effective
        /// value; otherwise, if there is a declaration for this attribute, and that
        /// declaration includes a default value, then that default value is the attribute's
        /// effective value; otherwise, the attribute does not exist on this element
        /// in the structure model until it has been explicitly added. Note that the
        /// nodeValue attribute on the Attr instance can also be used to retrieve the
        /// string version of the attribute's value(s).
        /// 
        /// In XML, where the value of an attribute can contain entity references, the
        /// child nodes of the Attr node provide a representation in which entity references
        /// are not expanded. These child nodes may be either Text or EntityReference
        /// nodes. Because the attribute type may be unknown, there are no tokenized
        /// attribute values.
{
public:
        const XMLString& name() const;
                /// Returns the name of this attribute.

        bool specified() const;
                /// If this attribute was explicitly given a value in the original document,
                /// this is true; otherwise, it is false. Note that the implementation is in
                /// charge of this attribute, not the user. If the user changes the value of
                /// the attribute (even if it ends up having the same value as the default value)
                /// then the specified flag is automatically flipped to true. To re-specify
                /// the attribute as the default value from the DTD, the user must delete the
                /// attribute. The implementation will then make a new attribute available with
                /// specified set to false and the default value (if one exists).
                /// In summary:
                /// 
                ///     * If the attribute has an assigned value in the document then specified
                ///       is true, and the value is the assigned value.
                ///     * If the attribute has no assigned value in the document and has a default
                ///       value in the DTD, then specified is false, and the value is the default
                ///       value in the DTD.
                ///     * If the attribute has no assigned value in the document and has a value
                ///       of #IMPLIED in the DTD, then the attribute does not appear in the structure
                ///       model of the document.
                ///     * If the attribute is not associated to any element (i.e. because it
                ///       was just created or was obtained from some removal or cloning operation)
                ///       specified is true.

        const XMLString& value() const;
                /// Returns the value of the attribute as a string. Character
                /// and general entity references are replaced with their values. See also the
                /// method getAttribute on the Element interface.

        const XMLString& getValue() const;
                /// Returns the value of the attribute as a string. Character
                /// and general entity references are replaced with their values. See also the
                /// method getAttribute on the Element interface.

        void setValue(const XMLString& value);
                /// Sets the value of the attribute as a string.
                /// This creates a Text node with the unparsed contents of the string.
                /// I.e. any characters that an XML processor would recognize as markup are
                /// instead treated as literal text. See also the method setAttribute on the
                /// Element interface.

        // DOM Level 2
        Element* ownerElement() const;
                /// The Element node this attribute is attached to or null 
                /// if this attribute is not in use.

        // Node
        Node* parentNode() const;
        const XMLString& nodeName() const;
        const XMLString& getNodeValue() const;
        void setNodeValue(const XMLString& value);
        unsigned short nodeType() const;
        Node* previousSibling() const;
        const XMLString& namespaceURI() const;
        XMLString prefix() const;
        const XMLString& localName() const;

        // Non-standard extensions
        XMLString innerText() const;

protected:
        Attr(Document* pOwnerDocument, Element* pOwnerElement, const XMLString& namespaceURI, const XMLString& localName, const XMLString& qname, const XMLString& value, bool specified = true);
        Attr(Document* pOwnerDocument, const Attr& attr);
        ~Attr();
        
        Node* copyNode(bool deep, Document* pOwnerDocument) const;

private:
        const Name& _name;
        XMLString   _value;
        bool        _specified;

        friend class Document;
        friend class Element;
        friend class DOMBuilder;
};


//
// inlines
//
inline const XMLString& Attr::name() const
{
        return _name.qname();
}


inline const XMLString& Attr::value() const
{
        return _value;
}


inline const XMLString& Attr::getValue() const
{
        return _value;
}


inline bool Attr::specified() const
{
        return _specified;
}


inline Element* Attr::ownerElement() const
{
        return static_cast<Element*>(_pParent);
}


} } // namespace Poco::XML


#endif // DOM_Attr_INCLUDED