# Poco::XML

# class Element

Library: XML
Package: DOM
Header: Poco/DOM/Element.h

## Description

The Element interface represents an element in an XML document. Elements may have attributes associated with them; since the Element interface inherits from Node, the generic Node interface attribute attributes may be used to retrieve the set of all attributes for an element. There are methods on the Element interface to retrieve either an Attr object by name or an attribute value by name. In XML, where an attribute value may contain entity references, an Attr object should be retrieved to examine the possibly fairly complex sub-tree representing the attribute value.

## Inheritance

Direct Base Classes: AbstractContainerNode

All Base Classes: AbstractContainerNode, AbstractNode, DOMObject, EventTarget, Node

## Member Summary

Member Functions: addAttributeNodeNP, attributes, copyNode, dispatchNodeInsertedIntoDocument, dispatchNodeRemovedFromDocument, getAttribute, getAttributeNS, getAttributeNode, getAttributeNodeNS, getChildElement, getChildElementNS, getElementById, getElementByIdNS, getElementsByTagName, getElementsByTagNameNS, hasAttribute, hasAttributeNS, hasAttributes, innerText, localName, namespaceURI, nodeName, nodeType, normalize, prefix, removeAttribute, removeAttributeNS, removeAttributeNode, setAttribute, setAttributeNS, setAttributeNode, setAttributeNodeNS, tagName

Inherited Functions: addEventListener, appendChild, attributes, autoRelease, bubbleEvent, captureEvent, childNodes, cloneNode, copyNode, dispatchAttrModified, dispatchCharacterDataModified, dispatchEvent, dispatchNodeInserted, dispatchNodeInsertedIntoDocument, dispatchNodeRemoved, dispatchNodeRemovedFromDocument, dispatchSubtreeModified, duplicate, events, eventsSuspended, findAttribute, findElement, findNode, firstChild, getNodeByPath, getNodeByPathNS, getNodeValue, hasAttributeValue, hasAttributes, hasChildNodes, innerText, insertBefore, isSupported, lastChild, localName, namesAreEqual, namespaceURI, nextSibling, nodeName, nodeType, nodeValue, normalize, ownerDocument, parentNode, prefix, previousSibling, release, removeChild, removeEventListener, replaceChild, setNodeValue, setOwnerDocument

## Constructors

### Element

Element(
Document * pOwnerDocument,
const Element & elem
);

### Element

Element(
Document * pOwnerDocument,
const XMLString & namespaceURI,
const XMLString & localName,
const XMLString & qname
);

## Destructor

### ~Element

~Element();

## Member Functions

### addAttributeNodeNP

Attr * addAttributeNodeNP(
Attr * oldAttr,
Attr * newAttr
);

For internal use only. Adds a new attribute after oldAttr. If oldAttr is 0, newAttr is set as first attribute. Returns newAttr. Does not fire any events.

### attributes

NamedNodeMap * attributes() const;

See also: Poco::XML::AbstractNode::attributes()

### getAttribute

const XMLString & getAttribute(
const XMLString & name
) const;

Retrieves an attribute value by name.

Returns the attribute's value, if the attribute exists, or an empty string otherwise.

### getAttributeNS

const XMLString & getAttributeNS(
const XMLString & namespaceURI,
const XMLString & localName
) const;

Retrieves an attribute value by name.

Returns the attribute's value, if the attribute exists, or an empty string otherwise.

### getAttributeNode

Attr * getAttributeNode(
const XMLString & name
) const;

Retrieves an Attr node by name.

### getAttributeNodeNS

Attr * getAttributeNodeNS(
const XMLString & namespaceURI,
const XMLString & localName
) const;

Retrieves an Attr node by name.

### getChildElement

Element * getChildElement(
const XMLString & name
) const;

Returns the first child element with the given name, or null if such an element does not exist.

This method is an extension to the W3C Document Object Model.

### getChildElementNS

Element * getChildElementNS(
const XMLString & namespaceURI,
const XMLString & localName
) const;

Returns the first child element with the given namespaceURI and localName, or null if such an element does not exist.

This method is an extension to the W3C Document Object Model.

### getElementById

Element * getElementById(
const XMLString & elementId,
const XMLString & idAttribute
) const;

Returns the first Element whose ID attribute (given in idAttribute) has the given elementId. If no such element exists, returns null.

This method is an extension to the W3C Document Object Model.

### getElementByIdNS

Element * getElementByIdNS(
const XMLString & elementId,
const XMLString & idAttributeURI,
const XMLString & idAttributeLocalName
) const;

Returns the first Element whose ID attribute (given in idAttributeURI and idAttributeLocalName) has the given elementId. If no such element exists, returns null.

This method is an extension to the W3C Document Object Model.

### getElementsByTagName

NodeList * getElementsByTagName(
const XMLString & name
) const;

Returns a NodeList of all descendant elements with a given tag name, in the order in which they would be encountered in a preorder traversal of the Element tree.

The special name "*" matches all tags.

The returned NodeList must be released with a call to release() when no longer needed.

### getElementsByTagNameNS

NodeList * getElementsByTagNameNS(
const XMLString & namespaceURI,
const XMLString & localName
) const;

Returns a NodeList of all the descendant Elements with a given local name and namespace URI in the order in which they are encountered in a preorder traversal of this Element tree.

The special value "*" matches all namespaces, or local names respectively.

The returned NodeList must be released with a call to release() when no longer needed.

### hasAttribute

bool hasAttribute(
const XMLString & name
) const;

Returns true if and only if the element has the specified attribute.

### hasAttributeNS

bool hasAttributeNS(
const XMLString & namespaceURI,
const XMLString & localName
) const;

Returns true if and only if the element has the specified attribute.

### hasAttributes

bool hasAttributes() const;

See also: Poco::XML::AbstractContainerNode::hasAttributes()

### innerText

XMLString innerText() const;

See also: Poco::XML::AbstractNode::innerText()

### localName

const XMLString & localName() const;

See also: Poco::XML::AbstractNode::localName()

### namespaceURI

const XMLString & namespaceURI() const;

See also: Poco::XML::AbstractNode::namespaceURI()

### nodeName

const XMLString & nodeName() const;

See also: Poco::XML::AbstractNode::nodeName()

### nodeType

unsigned short nodeType() const;

See also: Poco::XML::Node::nodeType()

### normalize

void normalize();

Puts all Text nodes in the full depth of the sub-tree underneath this Element, including attribute nodes, into a "normal" form where only markup (e.g., tags, comments, processing instructions, CDATA sections, and entity references) separates Text nodes, i.e., there are no adjacent Text nodes. This can be used to ensure that the DOM view of a document is the same as if it were saved and re-loaded, and is useful when operations (such as XPointer lookups) that depend on a particular document tree structure are to be used.

Note: In cases where the document contains CDATASections, the normalize operation alone may not be sufficient, since XPointers do not differentiate between Text nodes and CDATASection nodes.

See also: Poco::XML::AbstractNode::normalize()

### prefix

XMLString prefix() const;

See also: Poco::XML::AbstractNode::prefix()

### removeAttribute

void removeAttribute(
const XMLString & name
);

Removes an attribute by name.

### removeAttributeNS

void removeAttributeNS(
const XMLString & namespaceURI,
const XMLString & localName
);

Removes an attribute by name.

### removeAttributeNode

Attr * removeAttributeNode(
Attr * oldAttr
);

Removes the specified attribute.

### setAttribute

void setAttribute(
const XMLString & name,
const XMLString & value
);

Adds a new attribute. If an attribute with that name is already present in the element, its value is changed to be that of the value parameter. This value is a simple string; it is not parsed as it is being set. So any markup (such as syntax to be recognized as an entity reference) is treated as literal text, and needs to be appropriately escaped by the implementation when it is written out.

### setAttributeNS

void setAttributeNS(
const XMLString & namespaceURI,
const XMLString & qualifiedName,
const XMLString & value
);

Adds a new attribute. If an attribute with that name is already present in the element, its value is changed to be that of the value parameter.

### setAttributeNode

Attr * setAttributeNode(
Attr * newAttr
);

Adds a new attribute. If an attribute with that name is already present in the element, it is replaced by the new one.

### setAttributeNodeNS

Attr * setAttributeNodeNS(
Attr * newAttr
);

Adds a new attribute. If an attribute with that name is already present in the element, it is replaced by the new one.

### tagName

const XMLString & tagName() const;

Returns the name of the element.

For example, in

    <elementExample id="demo">
        ...
    </elementExample>

tagName has the value "elementExample". Note that this is case-preserving in XML, as are all of the operations of the DOM.

### copyNode

Node * copyNode(
bool deep,
Document * pOwnerDocument
) const;

See also: Poco::XML::AbstractNode::copyNode()

### dispatchNodeInsertedIntoDocument

void dispatchNodeInsertedIntoDocument();

See also: Poco::XML::AbstractContainerNode::dispatchNodeInsertedIntoDocument()

### dispatchNodeRemovedFromDocument

void dispatchNodeRemovedFromDocument();

See also: Poco::XML::AbstractContainerNode::dispatchNodeRemovedFromDocument()