QDomElement Class Reference

The QDomElement class represents one element in the DOM tree.

  1. #include <QDomElement>

Inherits: QDomNode.

Note: All functions in this class are reentrant.

Detailed Description

The QDomElement class represents one element in the DOM tree.

Elements have a tagName() and zero or more attributes associated with them. The tag name can be changed with setTagName().

Element attributes are represented by QDomAttr objects that can be queried using the attribute() and attributeNode() functions. You can set attributes with the setAttribute() and setAttributeNode() functions. Attributes can be removed with removeAttribute(). There are namespace-aware equivalents to these functions, i.e. setAttributeNS(), setAttributeNodeNS() and removeAttributeNS().

If you want to access the text of a node use text(), e.g.

  1. QDomElement e = //...
  2. //...
  3. QString s = e.text()

The text() function operates recursively to find the text (since not all elements contain text). If you want to find all the text in all of a node's children, iterate over the children looking for QDomText nodes, e.g.

  1.                 QString text;
  2. QDomElement element = doc.documentElement();
  3. for(QDomNode n = element.firstChild(); !n.isNull(); n = n.nextSibling())
  4.  {
  5.     QDomText t = n.toText();
  6.     if (!t.isNull())
  7.         text += t.data();
  8. }

Note that we attempt to convert each node to a text node and use text() rather than using firstChild().toText().data() or n.toText().data() directly on the node, because the node may not be a text element.

You can get a list of all the decendents of an element which have a specified tag name with elementsByTagName() or elementsByTagNameNS().

To browse the elements of a dom document use firstChildElement(), lastChildElement(), nextSiblingElement() and previousSiblingElement(). For example, to iterate over all child elements called "entry" in a root element called "database", you can use:

  1.                 QDomDocument doc = // ...
  2. QDomElement root = doc.firstChildElement("database");
  3. QDomElement elt = root.firstChildElement("entry");
  4. for (; !elt.isNull(); elt = elt.nextSiblingElement("entry"))  {
  5.     // ...
  6. }

For further information about the Document Object Model see Level 1 and Level 2 Core. For a more general introduction of the DOM implementation see the QDomDocument documentation.

Public Functions

Toggle details QDomElement

QDomElementQDomElement () ()

Constructs an empty element. Use the QDomDocument::createElement() function to construct elements with content.

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Toggle details QDomElement

QDomElementQDomElement ( const QDomElement &x ) ( const QDomElement &x )

Constructs a copy of x.

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().

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Toggle details QString QDomElement

attributeattribute ( const QString &name , const QString &defValue=QString() ...) ( const QString &name , const QString &defValue=QString() )const

Returns the attribute called name. If the attribute does not exist defValue is returned.

See also setAttribute(), attributeNode(), setAttributeNode(), and attributeNS().

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Toggle details QString QDomElement

attributeNSattributeNS ( const QString nsURI , const QString &localName , const QString &defValue=QString() ...) ( const QString nsURI , const QString &localName , const QString &defValue=QString() )const

Returns the attribute with the local name localName and the namespace URI nsURI. If the attribute does not exist defValue is returned.

See also setAttributeNS(), attributeNodeNS(), setAttributeNodeNS(), and attribute().

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Toggle details QDomAttr QDomElement

attributeNodeattributeNode ( const QString &name ) ( const QString &name )

Returns the QDomAttr object that corresponds to the attribute called name. If no such attribute exists a null attribute is returned.

See also setAttributeNode(), attribute(), setAttribute(), and attributeNodeNS().

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Toggle details QDomAttr QDomElement

attributeNodeNSattributeNodeNS ( const QString &nsURI , const QString &localName ...) ( const QString &nsURI , const QString &localName )

Returns the QDomAttr object that corresponds to the attribute with the local name localName and the namespace URI nsURI. If no such attribute exists a null attribute is returned.

See also setAttributeNodeNS(), setAttributeNode(), attribute(), and setAttribute().

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Toggle details QDomNamedNodeMap QDomElement

attributesattributes () ()const

Returns a QDomNamedNodeMap containing all this element's attributes.

See also attribute(), setAttribute(), attributeNode(), and setAttributeNode().

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Toggle details QDomNodeList QDomElement

elementsByTagNameelementsByTagName ( const QString &tagname ...) ( const QString &tagname )const

Returns a QDomNodeList containing all descendants of this element named tagname encountered during a preorder traversal of the element subtree with this element as its root. The order of the elements in the returned list is the order they are encountered during the preorder traversal.

See also elementsByTagNameNS() and QDomDocument::elementsByTagName().

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Toggle details QDomNodeList QDomElement

elementsByTagNameNSelementsByTagNameNS ( const QString &nsURI , const QString &localName ...) ( const QString &nsURI , const QString &localName )const

Returns a QDomNodeList containing all descendants of this element with local name localName and namespace URI nsURI encountered during a preorder traversal of the element subtree with this element as its root. The order of the elements in the returned list is the order they are encountered during the preorder traversal.

See also elementsByTagName() and QDomDocument::elementsByTagNameNS().

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Toggle details bool QDomElement

hasAttributehasAttribute ( const QString &name ) ( const QString &name )const

Returns true if this element has an attribute called name; otherwise returns false.

Note: This function does not take the presence of namespaces into account. As a result, the specified name will be tested against fully-qualified attribute names that include any namespace prefixes that may be present.

Use hasAttributeNS() to explicitly test for attributes with specific namespaces and names.

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Toggle details bool QDomElement

hasAttributeNShasAttributeNS ( const QString &nsURI , const QString &localName ...) ( const QString &nsURI , const QString &localName )const

Returns true if this element has an attribute with the local name localName and the namespace URI nsURI; otherwise returns false.

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Toggle details QDomNode::NodeType QDomElement

nodeTypenodeType () ()const

Returns ElementNode.

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Toggle details void QDomElement

removeAttributeremoveAttribute ( const QString &name ) ( const QString &name )

Removes the attribute called name name from this element.

See also setAttribute(), attribute(), and removeAttributeNS().

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Toggle details void QDomElement

removeAttributeNSremoveAttributeNS ( const QString &nsURI , const QString &localName ...) ( const QString &nsURI , const QString &localName )

Removes the attribute with the local name localName and the namespace URI nsURI from this element.

See also setAttributeNS(), attributeNS(), and removeAttribute().

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Toggle details QDomAttr QDomElement

removeAttributeNoderemoveAttributeNode ( const QDomAttr &oldAttr ...) ( const QDomAttr &oldAttr )

Removes the attribute oldAttr from the element and returns it.

See also attributeNode() and setAttributeNode().

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Toggle details void QDomElement

setAttributesetAttribute ( const QString &name , const QString &value ...) ( const QString &name , const QString &value )

Adds an attribute called name with value value. If an attribute with the same name exists, its value is replaced by value.

See also attribute(), setAttributeNode(), and setAttributeNS().

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Toggle details void QDomElement

setAttributesetAttribute ( const QString &name , int value ) ( const QString &name , int value )

This is an overloaded function.

The number is formatted according to the current locale.

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Toggle details void QDomElement

setAttributesetAttribute ( const QString &name , uint value ( const QString &name , uint value )

This is an overloaded function.

The number is formatted according to the current locale.

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Toggle details void QDomElement

setAttributesetAttribute ( const QString &name , qlonglong value ...) ( const QString &name , qlonglong value )

This is an overloaded function.

The number is formatted according to the current locale.

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Toggle details void QDomElement

setAttributesetAttribute ( const QString &name , qulonglong value ...) ( const QString &name , qulonglong value )

This is an overloaded function.

The number is formatted according to the current locale.

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Toggle details void QDomElement

setAttributesetAttribute ( const QString &name , floatvalue ...) ( const QString &name , floatvalue )

This is an overloaded function.

The number is formatted according to the current locale.

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Toggle details void QDomElement

setAttributesetAttribute ( const QString &name , double value ...) ( const QString &name , double value )

This is an overloaded function.

The number is formatted according to the current locale.

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Toggle details void QDomElement

setAttributeNSsetAttributeNS ( const QString nsURI , const QString &qName , const QString &value ...) ( const QString nsURI , const QString &qName , const QString &value )

Adds an attribute with the qualified name qName and the namespace URI nsURI with the value value. If an attribute with the same local name and namespace URI exists, its prefix is replaced by the prefix of qName and its value is repaced by value.

Although qName is the qualified name, the local name is used to decide if an existing attribute's value should be replaced.

See also attributeNS(), setAttributeNodeNS(), and setAttribute().

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Toggle details void QDomElement

setAttributeNSsetAttributeNS ( const QString nsURI , const QString &qName , int value ...) ( const QString nsURI , const QString &qName , int value )

This is an overloaded function.

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Toggle details void QDomElement

setAttributeNSsetAttributeNS ( const QString nsURI , const QString &qName , uint value ...) ( const QString nsURI , const QString &qName , uint value )

This is an overloaded function.

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Toggle details void QDomElement

setAttributeNSsetAttributeNS ( const QString nsURI , const QString &qName , qlonglong value ...) ( const QString nsURI , const QString &qName , qlonglong value )

This is an overloaded function.

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Toggle details void QDomElement

setAttributeNSsetAttributeNS ( const QString nsURI , const QString &qName , qulonglong value ...) ( const QString nsURI , const QString &qName , qulonglong value )

This is an overloaded function.

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Toggle details void QDomElement

setAttributeNSsetAttributeNS ( const QString nsURI , const QString &qName , double value ...) ( const QString nsURI , const QString &qName , double value )

This is an overloaded function.

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Toggle details QDomAttr QDomElement

setAttributeNodesetAttributeNode ( const QDomAttr &newAttr ( const QDomAttr &newAttr )

Adds the attribute newAttr to this element.

If the element has another attribute that has the same name as newAttr, this function replaces that attribute and returns it; otherwise the function returns a null attribute.

See also attributeNode(), setAttribute(), and setAttributeNodeNS().

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Toggle details QDomAttr QDomElement

setAttributeNodeNSsetAttributeNodeNS ( const QDomAttr &newAttr ...) ( const QDomAttr &newAttr )

Adds the attribute newAttr to this element.

If the element has another attribute that has the same local name and namespace URI as newAttr, this function replaces that attribute and returns it; otherwise the function returns a null attribute.

See also attributeNodeNS(), setAttributeNS(), and setAttributeNode().

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Toggle details void QDomElement

setTagNamesetTagName ( const QString &name ) ( const QString &name )

Sets this element's tag name to name.

See also tagName().

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Toggle details QString QDomElement

tagNametagName () ()const

Returns the tag name of this element. For an XML element like this:

  1. <img src="myimg.png">

the tagname would return "img".

See also setTagName().

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Toggle details QString QDomElement

texttext () ()const

Returns the element's text or an empty string.

Example:

  1. <h1>Hello <b>Qt</b> <![CDATA[<xml is cool>]]></h1>

The function text() of the QDomElement for the <h1> tag, will return the following text:

  1. Hello Qt <xml is cool>

Comments are ignored by this function. It only evaluates QDomText and QDomCDATASection objects.

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Toggle details QDomElement & QDomElement

operator=operator= ( const QDomElement &x ) ( const QDomElement &x )

Assigns x to this DOM element.

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().

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