CopperSpice API  1.9.1
QXmlItem Class Reference

The QXmlItem class contains either an XML node or an atomic value. More...

Public Typedefs

typedef QAbstractXmlForwardIterator< QXmlItem > Iterator
 

Public Methods

 QXmlItem ()
 
 QXmlItem (const QVariant &atomicValue)
 
 QXmlItem (const QXmlItem &other)
 
 QXmlItem (const QXmlNodeModelIndex &node)
 
 ~QXmlItem ()
 
bool isAtomicValue () const
 
bool isNode () const
 
bool isNull () const
 
QXmlItem & operator= (const QXmlItem &other)
 
QVariant toAtomicValue () const
 
QXmlNodeModelIndex toNodeModelIndex () const
 

Detailed Description

The QXmlItem class contains either an XML node or an atomic value.

In XQuery, all expressions evaluate to a sequence of items, where each item is either an XML node or an atomic value. The query in the following snippet evaluates to sequence of five items.

<aNode/>,
xs:base64Binary("FFFF"),
current-date(),
3e3, (: A floating point value :)
attribute {"name"} {()}

The five items are: An element, an atomic value (binary data encoded in base64), a date, a float, and an attribute.

QXmlItem is the class that represents these XQuery items in the CsXmlPatterns library. A non-null instance of QXmlItem is either a node or an atomic value. Calling isNode() or isAtomicValue() tells you which it is. Atomic values are represented elsewhere in the CopperSpice API as instances of QVariant, and an instance of QXmlItem that represents an atomic value can be converted to a QVariant by calling toAtomicValue(). An QXmlItem which wraps a node is represented elsewhere as an instance of QXmlNodeModelIndex. A node QXmlItem can be converted to a QXmlNodeModelIndex by calling toNodeModelIndex().

A default constructed QXmlItem is considered null. An instance of QXmlItem will be left dangling if the XML node model it refers to is deleted, if it is a QXmlNodeModelIndex.

See also
isNode()

Member Typedef Documentation

A QAbstractXmlForwardIterator over QXmlItem.

Constructor & Destructor Documentation

QXmlItem::QXmlItem ( )

Constructs a null QXmlItem that is neither a node nor an atomic value. isNull() returns true for a default constructed instance.

QXmlItem::QXmlItem ( const QXmlItem &  other)

The copy constructor constructs a copy of other.

QXmlItem::QXmlItem ( const QXmlNodeModelIndex node)

Constructs a node QXmlItem that is a copy of node.

See also
isNode()
QXmlItem::QXmlItem ( const QVariant atomicValue)

Constructs an atomic value QXmlItem with atomicValue.

See also
isAtomicValue()
QXmlItem::~QXmlItem ( )

Destructor.

Method Documentation

bool QXmlItem::isAtomicValue ( ) const

Returns true if this item is an atomic value. Returns false if it is a node or null.

See also
isNull(), isNode()
bool QXmlItem::isNode ( ) const

Returns true if this item is a Node. Returns false if it is an atomic value or null.

See also
isNull(), isAtomicValue()
bool QXmlItem::isNull ( ) const

Returns true if this QXmlItem is neither a node nor an atomic value. Default constructed instances of QXmlItem are null.

QXmlItem & QXmlItem::operator= ( const QXmlItem &  other)

Copy assigns from other and returns a reference to this object.

QVariant QXmlItem::toAtomicValue ( ) const

If this QXmlItem represents an atomic value, it is converted to an appropriate QVariant and returned. If this QXmlItem is not an atomic value, the return value is a default constructed QVariant. You can call isAtomicValue() to test whether the item is an atomic value.

See also
isAtomicValue()
QXmlNodeModelIndex QXmlItem::toNodeModelIndex ( ) const

If this QXmlItem represents a node, it returns the item as a QXmlNodeModelIndex. If this QXmlItem is not a node, the return value is undefined. You can call isNode() to test whether the item is a node.

See also
isNode()