QDomNode Class Reference
[XML module]

Detailed Description

Many functions in the DOM return a QDomNode.

You can find out the type of a node using isAttr(), isCDATASection(), isDocumentFragment(), isDocument(), isDocumentType(), isElement(), isEntityReference(), isText(), isEntity(), isNotation(), isProcessingInstruction(), isCharacterData() and isComment().

A QDomNode can be converted into one of its subclasses using toAttr(), toCDATASection(), toDocumentFragment(), toDocument(), toDocumentType(), toElement(), toEntityReference(), toText(), toEntity(), toNotation(), toProcessingInstruction(), toCharacterData() or toComment(). You can convert a node to a null node with clear().

Copies of the QDomNode class share their data using explicit sharing. This means that modifying one node will change all copies. This is especially useful in combination with functions which return a QDomNode, e.g. firstChild(). You can make an independent (deep) copy of the node with cloneNode().

Nodes are inserted with insertBefore(), insertAfter() or appendChild(). You can replace one node with another using replaceChild() and remove a node with removeChild().

To traverse nodes use firstChild() to get a node's first child (if any), and nextSibling() to traverse. QDomNode also provides lastChild(), previousSibling() and parentNode(). To find the first child node with a particular node name use namedItem().

To find out if a node has children use hasChildNodes() and to get a list of all of a node's children use childNodes().

The node's name and value (the meaning of which varies depending on its type) is returned by nodeName() and nodeValue() respectively. The node's type is returned by nodeType(). The node's value can be set with setNodeValue().

The document to which the node belongs is returned by ownerDocument().

Adjacent QDomText nodes can be merged into a single node with normalize().

QDomElement nodes have attributes which can be retrieved with attributes().

QDomElement and QDomAttr nodes can have namespaces which can be retrieved with namespaceURI(). Their local name is retrieved with localName(), and their prefix with prefix(). The prefix can be set with setPrefix().

You can write the XML representation of the node to a text stream with save().

The following example looks for the first element in an XML document and prints the names of all the elements that are its direct children.

    QDomDocument d;
    d.setContent( someXML );
    QDomNode n = d.firstChild();
    while ( !n.isNull() ) {
        if ( n.isElement() ) {
            QDomElement e = n.toElement();
            cout << "Element name: " << e.tagName() << endl;
            break;
        }
        n = n.nextSibling();
    }
    

For further information about the Document Object Model see http://www.w3.org/TR/REC-DOM-Level-1/ and http://www.w3.org/TR/DOM-Level-2-Core/. For a more general introduction of the DOM implementation see the QDomDocument documentation.

See also XML.

Member Type Documentation

QDomNode::NodeType

This enum defines the type of the node:

• QDomNode::ElementNode
• QDomNode::AttributeNode
• QDomNode::TextNode
• QDomNode::CDATASectionNode
• QDomNode::EntityReferenceNode
• QDomNode::EntityNode
• QDomNode::ProcessingInstructionNode
• QDomNode::CommentNode
• QDomNode::DocumentNode
• QDomNode::DocumentTypeNode
• QDomNode::DocumentFragmentNode
• QDomNode::NotationNode
• QDomNode::BaseNode - A QDomNode object, i.e. not a QDomNode subclass.
• QDomNode::CharacterDataNode

Member Function Documentation

QDomNode::QDomNode ()

QDomNode::QDomNode ( const QDomNode & n )

The data of the copy is shared (shallow copy): modifying one node will also change the other. If you want to make a deep copy, use cloneNode().

QDomNode::~QDomNode () [virtual]

QDomNode QDomNode::appendChild ( const QDomNode & newChild ) [virtual]

If newChild is the child of another node, it is reparented to this node. If newChild is a child of this node, then its position in the list of children is changed.

If newChild is a QDomDocumentFragment, then the children of the fragment are removed from the fragment and appended.

Returns a new reference to newChild.

See also insertBefore(), insertAfter(), replaceChild(), and removeChild().

QDomNamedNodeMap QDomNode::attributes () const [virtual]

Changing the attributes in the map will also change the attributes of this QDomNode.

Reimplemented in QDomElement.

QDomNodeList QDomNode::childNodes () const [virtual]

Most often you will call this function on a QDomElement object.

For example, if the XML document looks like this:

    <body>
    <h1>Heading</h1>
    <p>Hello <b>you</b></p>
    </body>
    

The nodes in the list are not copied; so changing the nodes in the list will also change the children of this node.

See also firstChild() and lastChild().

void QDomNode::clear ()

See also isNull().

QDomNode QDomNode::cloneNode ( bool deep = TRUE ) const [virtual]

If deep is TRUE, then the cloning is done recursively which means that all the node's children are deep copied too. If deep is FALSE only the node itself is copied and the copy will have no child nodes.

QDomNode QDomNode::firstChild () const [virtual]

See also lastChild() and childNodes().

Example: xml/outliner/outlinetree.cpp.

bool QDomNode::hasAttributes () const [virtual]

See also attributes().

bool QDomNode::hasChildNodes () const [virtual]

QDomNode QDomNode::insertAfter ( const QDomNode & newChild, const QDomNode & refChild ) [virtual]

If newChild is the child of another node, it is reparented to this node. If newChild is a child of this node, then its position in the list of children is changed.

If newChild is a QDomDocumentFragment, then the children of the fragment are removed from the fragment and inserted after refChild.

Returns a new reference to newChild on success or a null node on failure.

See also insertBefore(), replaceChild(), removeChild(), and appendChild().

QDomNode QDomNode::insertBefore ( const QDomNode & newChild, const QDomNode & refChild ) [virtual]

If newChild is the child of another node, it is reparented to this node. If newChild is a child of this node, then its position in the list of children is changed.

If newChild is a QDomDocumentFragment, then the children of the fragment are removed from the fragment and inserted before refChild.

Returns a new reference to newChild on success or a null node on failure.

See also insertAfter(), replaceChild(), removeChild(), and appendChild().

bool QDomNode::isAttr () const [virtual]

If this function returns TRUE, it does not imply that this object is a QDomAttribute; you can get the QDomAttribute with toAttribute().

See also toAttr().

Reimplemented in QDomAttr.

bool QDomNode::isCDATASection () const [virtual]

If this function returns TRUE, it does not imply that this object is a QDomCDATASection; you can get the QDomCDATASection with toCDATASection().

See also toCDATASection().

Reimplemented in QDomCDATASection.

bool QDomNode::isCharacterData () const [virtual]

If this function returns TRUE, it does not imply that this object is a QDomCharacterData; you can get the QDomCharacterData with toCharacterData().

See also toCharacterData().

Reimplemented in QDomCharacterData.

bool QDomNode::isComment () const [virtual]

If this function returns TRUE, it does not imply that this object is a QDomComment; you can get the QDomComment with toComment().

See also toComment().

Reimplemented in QDomComment.

bool QDomNode::isDocument () const [virtual]

If this function returns TRUE, it does not imply that this object is a QDomDocument; you can get the QDomDocument with toDocument().

See also toDocument().

Reimplemented in QDomDocument.

bool QDomNode::isDocumentFragment () const [virtual]

If this function returns TRUE, it does not imply that this object is a QDomDocumentFragment; you can get the QDomDocumentFragment with toDocumentFragment().

See also toDocumentFragment().

Reimplemented in QDomDocumentFragment.

bool QDomNode::isDocumentType () const [virtual]

If this function returns TRUE, it does not imply that this object is a QDomDocumentType; you can get the QDomDocumentType with toDocumentType().

See also toDocumentType().

Reimplemented in QDomDocumentType.

bool QDomNode::isElement () const [virtual]

If this function returns TRUE, it does not imply that this object is a QDomElement; you can get the QDomElement with toElement().

See also toElement().

Example: xml/outliner/outlinetree.cpp.

Reimplemented in QDomElement.

bool QDomNode::isEntity () const [virtual]

If this function returns TRUE, it does not imply that this object is a QDomEntity; you can get the QDomEntity with toEntity().

See also toEntity().

Reimplemented in QDomEntity.

bool QDomNode::isEntityReference () const [virtual]

If this function returns TRUE, it does not imply that this object is a QDomEntityReference; you can get the QDomEntityReference with toEntityReference().

See also toEntityReference().

Reimplemented in QDomEntityReference.

bool QDomNode::isNotation () const [virtual]

If this function returns TRUE, it does not imply that this object is a QDomNotation; you can get the QDomNotation with toNotation().

See also toNotation().

Reimplemented in QDomNotation.

bool QDomNode::isNull () const

Example: xml/outliner/outlinetree.cpp.

bool QDomNode::isProcessingInstruction () const [virtual]

If this function returns TRUE, it does not imply that this object is a QDomProcessingInstruction; you can get the QProcessingInstruction with toProcessingInstruction().

See also toProcessingInstruction().

Reimplemented in QDomProcessingInstruction.

bool QDomNode::isSupported ( const QString & feature, const QString & version ) const [virtual]

See also QDomImplementation::hasFeature().

bool QDomNode::isText () const [virtual]

If this function returns TRUE, it does not imply that this object is a QDomText; you can get the QDomText with toText().

See also toText().

Reimplemented in QDomText.

QDomNode QDomNode::lastChild () const [virtual]

See also firstChild() and childNodes().

QString QDomNode::localName () const [virtual]

Only nodes of type ElementNode or AttributeNode can have namespaces. A namespace must have been specified at creation time; it is not possible to add a namespace afterwards.

See also prefix(), namespaceURI(), QDomDocument::createElementNS(), and QDomDocument::createAttributeNS().

QDomNode QDomNode::namedItem ( const QString & name ) const

If no such direct child exists, a null node is returned.

See also nodeName().

QString QDomNode::namespaceURI () const [virtual]

Only nodes of type ElementNode or AttributeNode can have namespaces. A namespace URI must be specified at creation time and cannot be changed later.

See also prefix(), localName(), QDomDocument::createElementNS(), and QDomDocument::createAttributeNS().

QDomNode QDomNode::nextSibling () const [virtual]

If you have XML like this:

    <h1>Heading</h1>
    <p>The text...</p>
    <h2>Next heading</h2>
    

See also previousSibling().

Example: xml/outliner/outlinetree.cpp.

QString QDomNode::nodeName () const [virtual]

The meaning of the name depends on the subclass:

See also nodeValue().

Example: xml/outliner/outlinetree.cpp.

QDomNode::NodeType QDomNode::nodeType () const [virtual]

See also toAttr(), toCDATASection(), toDocumentFragment(), toDocument(), toDocumentType(), toElement(), toEntityReference(), toText(), toEntity(), toNotation(), toProcessingInstruction(), toCharacterData(), and toComment().

Reimplemented in QDomDocumentType, QDomDocument, QDomDocumentFragment, QDomCharacterData, QDomAttr, QDomElement, QDomNotation, QDomEntity, QDomEntityReference, and QDomProcessingInstruction.

QString QDomNode::nodeValue () const [virtual]

The meaning of the value depends on the subclass:

All the other subclasses do not have a node value and will return QString::null.

See also setNodeValue() and nodeName().

Example: xml/outliner/outlinetree.cpp.

void QDomNode::normalize () [virtual]

bool QDomNode::operator!= ( const QDomNode & n ) const

QDomNode & QDomNode::operator= ( const QDomNode & n )

The data of the copy is shared (shallow copy): modifying one node will also change the other. If you want to make a deep copy, use cloneNode().

bool QDomNode::operator== ( const QDomNode & n ) const

QDomDocument QDomNode::ownerDocument () const [virtual]

QDomNode QDomNode::parentNode () const [virtual]

QString QDomNode::prefix () const [virtual]

Only nodes of type ElementNode or AttributeNode can have namespaces. A namespace prefix must be specified at creation time. If a node was created with a namespace prefix, you can change it later with setPrefix().

If you create an element or attribute with QDomDocument::createElement() or QDomDocument::createAttribute(), the prefix will be QString::null. If you use QDomDocument::createElementNS() or QDomDocument::createAttributeNS() instead, the prefix will not be QString::null; but it might be an empty string if the name does not have a prefix.

See also setPrefix(), localName(), namespaceURI(), QDomDocument::createElementNS(), and QDomDocument::createAttributeNS().

QDomNode QDomNode::previousSibling () const [virtual]

For example, if you have XML like this:

    <h1>Heading</h1>
    <p>The text...</p>
    <h2>Next heading</h2>
    

See also nextSibling().

QDomNode QDomNode::removeChild ( const QDomNode & oldChild ) [virtual]

Returns a new reference to oldChild on success or a null node on failure.

See also insertBefore(), insertAfter(), replaceChild(), and appendChild().

QDomNode QDomNode::replaceChild ( const QDomNode & newChild, const QDomNode & oldChild ) [virtual]

If newChild is the child of another node, it is reparented to this node. If newChild is a child of this node, then its position in the list of children is changed.

If newChild is a QDomDocumentFragment, then oldChild is replaced by all of the children of the fragment.

Returns a new reference to oldChild on success or a null node an failure.

See also insertBefore(), insertAfter(), removeChild(), and appendChild().

void QDomNode::save ( QTextStream & str, int indent ) const

void QDomNode::setNodeValue ( const QString & v ) [virtual]

See also nodeValue().

void QDomNode::setPrefix ( const QString & pre ) [virtual]

Only nodes of type ElementNode or AttributeNode can have namespaces. A namespace prefix must have be specified at creation time; it is not possible to add a namespace prefix afterwards.

See also prefix(), localName(), namespaceURI(), QDomDocument::createElementNS(), and QDomDocument::createAttributeNS().

QDomAttr QDomNode::toAttr ()

See also isAttr().

QDomCDATASection QDomNode::toCDATASection ()

See also isCDATASection().

QDomCharacterData QDomNode::toCharacterData ()

See also isCharacterData().

QDomComment QDomNode::toComment ()

See also isComment().

QDomDocument QDomNode::toDocument ()

See also isDocument().

QDomDocumentFragment QDomNode::toDocumentFragment ()

See also isDocumentFragment().

QDomDocumentType QDomNode::toDocumentType ()

See also isDocumentType().

QDomElement QDomNode::toElement ()

See also isElement().

Example: xml/outliner/outlinetree.cpp.

QDomEntity QDomNode::toEntity ()

See also isEntity().

QDomEntityReference QDomNode::toEntityReference ()

See also isEntityReference().

QDomNotation QDomNode::toNotation ()

See also isNotation().

QDomProcessingInstruction QDomNode::toProcessingInstruction ()

See also isProcessingInstruction().

QDomText QDomNode::toText ()

See also isText().

Related Functions

QTextStream & operator<< ( QTextStream & str, const QDomNode & node )

Writes the XML representation of the node node and all its children to the stream str.

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