Qt 5.11 | Qt XML Patterns | C++ Classes | QXmlNodeModelIndex

Qt 5.11.3 Reference Documentation

# QXmlNodeModelIndex Class

The QXmlNodeModelIndex class identifies a node in an XML node model subclassed from QAbstractXmlNodeModel. More...

Header: | #include <QXmlNodeModelIndex>
qmake: | QT += xmlpatterns
Since: | Qt 4.4

- List of all members, including inherited members

Note: All functions in this class are reentrant.

## Public Types

enum | DocumentOrder { Precedes, Follows, Is }
typedef | List
enum | NodeKind { Attribute, Text, Comment, Document, ..., ProcessingInstruction }

## Public Functions

| QXmlNodeModelIndex()
| QXmlNodeModelIndex(const QXmlNodeModelIndex &other)
qint64 | additionalData() const
QUrl | baseUri() const
QXmlNodeModelIndex::DocumentOrder | compareOrder(const QXmlNodeModelIndex &other) const
qint64 | data() const
QUrl | documentUri() const
void * | internalPointer() const
bool | is(const QXmlNodeModelIndex &other) const
bool | isDeepEqual(const QXmlNodeModelIndex &other) const
bool | isNull() const
QExplicitlySharedDataPointer<QAbstractXmlForwardIterator<QXmlNodeModelIndex> > | iterate(const QXmlNodeModelIndex::Axis axis) const
QXmlNodeModelIndex::NodeKind | kind() const
const QAbstractXmlNodeModel * | model() const
QXmlName | name() const
QVector<QXmlName> | namespaceBindings() const
QXmlName::NamespaceCode | namespaceForPrefix(const QXmlName::PrefixCode prefix) const
void | reset()
QXmlNodeModelIndex | root() const
void | sendNamespaces(QAbstractXmlReceiver *const receiver) const
QExplicitlySharedDataPointer<QAbstractXmlForwardIterator<QPatternist::Item> > | sequencedTypedValue() const
QString | stringValue() const
QPatternist::ItemTypePtr | type() const
bool | operator!=(const QXmlNodeModelIndex &other) const
bool | operator==(const QXmlNodeModelIndex &other) const

## Detailed Description

The QXmlNodeModelIndex class identifies a node in an XML node model subclassed from QAbstractXmlNodeModel.

QXmlNodeModelIndex is an index into an XML node model. It contains:

- A pointer to an XML node model, which is returned by model(), and
- Some data, which is returned by data(), internalPointer(), and additionalData().

Because QXmlNodeModelIndex is intentionally a simple class, it doesn't have member functions for accessing the properties of nodes. For example, it doesn't have functions for getting a node's name or its list of attributes or child nodes. If you find that you need to retrieve this kind of information from your query results, there are two ways to proceed.

- Send the output of your XQuery to an XML receiver, or
- Let your XQuery do all the work to produce the desired result.

The second case is explained by example. Suppose you want to populate a list widget with the values of certain attributes from a set of result elements. You could write an XQuery to return the set of elements, and then you would write the code to iterate over the result elements, get their attributes, and extract the desired string values. But the simpler way is to just augment your XQuery to finding the desired attribute values. Then all you have to do is evaluate the XQuery using the version of QXmlQuery::evaluateTo() that populates a QStringList, which you can send directly to your widget.

QXmlNodeModelIndex doesn't impose any restrictions on the `data` value an QXmlNodeModelIndex should contain. The meaning of the data left to the associated node model. Because QXmlNodeModelIndex depends on a particular subclass of QAbstractXmlNodeModel for its existence, the only way you can create an instance of QXmlNodeModelIndex is by asking the node model to create one for you with QAbstractXmlNodeModel::createIndex(). Since that function is protected, it is usually a good idea to write a public function that creates a QXmlNodeModelIndex from arguments that are appropriate for your particular node model.

A default constructed node index is said to be null, i.e., isNull() returns true.

QXmlNodeModelIndex and QAbstractXmlNodeModel follow the same design pattern used for QModelIndex and QAbstractItemModel.

## Member Type Documentation

### enum QXmlNodeModelIndex::DocumentOrder

Identifies the specific node comparison operator that should be used.

Constant | Value | Description
--- | --- | ---
`QXmlNodeModelIndex::Precedes` | `-1` | Signifies the `\<\<` operator. Test whether the first operand precedes the second in the document.
`QXmlNodeModelIndex::Follows` | `1` | Signifies the `\>\>` operator. Test whether the first operand follows the second in the document.
`QXmlNodeModelIndex::Is` | `0` | Signifies the `is` operator. Test whether two nodes have the same node identity.

### typedef QXmlNodeModelIndex::List

Typedef for QList<QXmlNodeModelIndex>.

### enum QXmlNodeModelIndex::NodeKind

Identifies a kind of node.

Constant | Value | Description
--- | --- | ---
`QXmlNodeModelIndex::Attribute` | `1` | Identifies an attribute node
`QXmlNodeModelIndex::Text` | `64` | Identifies a text node
`QXmlNodeModelIndex::Comment` | `2` | Identifies a comment node
`QXmlNodeModelIndex::Document` | `4` | Identifies a document node
`QXmlNodeModelIndex::Element` | `8` | Identifies an element node
`QXmlNodeModelIndex::Namespace` | `16` | Identifies a namespace node
`QXmlNodeModelIndex::ProcessingInstruction` | `32` | Identifies a processing instruction.

Note that the optional XML declaration at very beginning of the XML document is not a processing instruction

See also QAbstractXmlNodeModel::kind().

## Member Function Documentation

### QXmlNodeModelIndex::QXmlNodeModelIndex()

Default constructs an instance of QXmlNodeModelIndex.

### QXmlNodeModelIndex::QXmlNodeModelIndex(const QXmlNodeModelIndex &other)

Default constructs an instance of QXmlNodeModelIndex.

### qint64 QXmlNodeModelIndex::additionalData() const

### QUrl QXmlNodeModelIndex::baseUri() const

### QXmlNodeModelIndex::DocumentOrder QXmlNodeModelIndex::compareOrder(const QXmlNodeModelIndex &other) const

### qint64 QXmlNodeModelIndex::data() const

### QUrl QXmlNodeModelIndex::documentUri() const

### void *QXmlNodeModelIndex::internalPointer() const

### bool QXmlNodeModelIndex::is(const QXmlNodeModelIndex &other) const

### bool QXmlNodeModelIndex::isDeepEqual(const QXmlNodeModelIndex &other) const

### bool QXmlNodeModelIndex::isNull() const

### QExplicitlySharedDataPointer<QAbstractXmlForwardIterator<QXmlNodeModelIndex> > QXmlNodeModelIndex::iterate(const QXmlNodeModelIndex::Axis axis) const

### QXmlNodeModelIndex::NodeKind QXmlNodeModelIndex::kind() const

### const QAbstractXmlNodeModel *QXmlNodeModelIndex::model() const

### QXmlName QXmlNodeModelIndex::name() const

### QVector<QXmlName> QXmlNodeModelIndex::namespaceBindings() const

### QXmlName::NamespaceCode QXmlNodeModelIndex::namespaceForPrefix(const QXmlName::PrefixCode prefix) const

### void QXmlNodeModelIndex::reset()

### QXmlNodeModelIndex QXmlNodeModelIndex::root() const

### void QXmlNodeModelIndex::sendNamespaces(QAbstractXmlReceiver *const receiver) const

### QExplicitlySharedDataPointer<QAbstractXmlForwardIterator<QPatternist::Item> > QXmlNodeModelIndex::sequencedTypedValue() const

### QString QXmlNodeModelIndex::stringValue() const

### QPatternist::ItemTypePtr QXmlNodeModelIndex::type() const

### bool QXmlNodeModelIndex::operator!=(const QXmlNodeModelIndex &other) const

Returns true if other is the same node as this.

### bool QXmlNodeModelIndex::operator==(const QXmlNodeModelIndex &other) const

Returns true if this node is the same as other. This operator does not compare values, children, or names of nodes. It compares node identities, i.e., whether two nodes are from the same document and are found at the exact same place.