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DOM_Element Class Reference

Inheritance diagram for DOM_Element:


Public Methods
Constructors and assignment operator
	DOM_Element ()
	DOM_Element (const DOM_Element &other)
DOM_Element &	operator= (const DOM_Element &other)
DOM_Element &	operator= (const DOM_NullPtr *val)
Destructor.
	~DOM_Element ()
Getter functions.
DOMString	getTagName () const
DOMString	getAttribute (const DOMString &name) const
DOM_Attr	getAttributeNode (const DOMString &name) const
DOM_NodeList	getElementsByTagName (const DOMString &name) const
Set functions.
void	setAttribute (const DOMString &name, const DOMString &value)
DOM_Attr	setAttributeNode (DOM_Attr newAttr)
Functions which modify the Element.
DOM_Attr	removeAttributeNode (DOM_Attr oldAttr)
void	removeAttribute (const DOMString &name)
Functions introduced in DOM Level 2.
DOMString	getAttributeNS (const DOMString &namespaceURI, const DOMString &localName) const
void	setAttributeNS (const DOMString &namespaceURI, const DOMString &qualifiedName, const DOMString &value)
void	removeAttributeNS (const DOMString &namespaceURI, const DOMString &localName)
DOM_Attr	getAttributeNodeNS (const DOMString &namespaceURI, const DOMString &localName) const
DOM_Attr	setAttributeNodeNS (DOM_Attr newAttr)
DOM_NodeList	getElementsByTagNameNS (const DOMString &namespaceURI, const DOMString &localName) const
bool	hasAttributes () const
bool	hasAttribute (const DOMString &name) const
bool	hasAttributeNS (const DOMString &namespaceURI, const DOMString &localName) const
Protected Methods
	DOM_Element (ElementImpl *impl)
Friends
class	DOM_Document
class	DOM_Attr
class	TraverseSchema

Detailed Description

By far the vast majority of objects (apart from text) that authors encounter when traversing a document are DOM_Element nodes.

Assume the following XML document:<elementExample id="demo"> <subelement1/> <subelement2><subsubelement/></subelement2> </elementExample>

When represented using DOM, the top node is an DOM_Element node for "elementExample", which contains two child DOM_Element nodes, one for "subelement1" and one for "subelement2". "subelement1" contains no child nodes.

Elements may have attributes associated with them; since the DOM_Element interface inherits from DOM_Node, the generic DOM_Node interface method getAttributes may be used to retrieve the set of all attributes for an element. There are methods on the DOM_Element interface to retrieve either an DOM_Attr object by name or an attribute value by name. In XML, where an attribute value may contain entity references, an DOM_Attr object should be retrieved to examine the possibly fairly complex sub-tree representing the attribute value. On the other hand, in HTML, where all attributes have simple string values, methods to directly access an attribute value can safely be used as a convenience.

Constructor & Destructor Documentation

DOM_Element::DOM_Element ( )

Default constructor for DOM_Element. The resulting object does not refer to an actual Element node; it will compare == to 0, and is similar to a null object reference variable in Java. It may subsequently be assigned to refer to an actual Element node.
New comment nodes are created by DOM_Document::createElement().

DOM_Element::DOM_Element ( const DOM_Element & other )

Copy constructor. Creates a new DOM_Element that refers to the same underlying actual element as the original.

Parameters:

other The object to be copied

DOM_Element::~DOM_Element ( )

Destructor. The object being destroyed is the reference object, not the underlying Element itself.

Member Function Documentation

DOMString DOM_Element::getAttribute ( const DOMString & name ) const

Retrieves an attribute value by name.

Parameters:

name The name of the attribute to retrieve.

Returns:
The DOM_Attr value as a string, or the empty string if that attribute does not have a specified or default value.

DOM_Attr DOM_Element::getAttributeNode ( const DOMString & name ) const

Retrieves an DOM_Attr node by name.

Parameters:

name The name (nodeName) of the attribute to retrieve.

Returns:
The DOM_Attr node with the specified name (nodeName) or null if there is no such attribute.

DOM_Attr DOM_Element::getAttributeNodeNS ( const DOMString & namespaceURI,

const DOMString & localName

) const

Retrieves an DOM_Attr node by local name and namespace URI.

Parameters:

namespaceURI The namespace URI of the attribute to retrieve.

localName The local name of the attribute to retrieve.

Returns:
The DOM_Attr node with the specified attribute local name and namespace URI or null if there is no such attribute.

DOMString DOM_Element::getAttributeNS ( const DOMString & namespaceURI,

const DOMString & localName

) const

Retrieves an attribute value by local name and namespace URI.

Parameters:

namespaceURI The namespace URI of the attribute to retrieve.

localName The local name of the attribute to retrieve.

Returns:
The DOM_Attr value as a string, or an null if that attribute does not have a specified or default value.

DOM_NodeList DOM_Element::getElementsByTagName ( const DOMString & 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 DOM_Element tree.

Parameters:

name The name of the tag to match on. The special value "*" matches all tags.

Returns:
A list of matching DOM_Element nodes.

DOM_NodeList DOM_Element::getElementsByTagNameNS ( const DOMString & namespaceURI,

const DOMString & localName

) const

Returns a DOM_NodeList of all the DOM_Elements with a given local name and namespace URI in the order in which they would be encountered in a preorder traversal of the DOM_Document tree, starting from this node.

Parameters:

namespaceURI The namespace URI of the elements to match on. The special value "*" matches all namespaces.

localName The local name of the elements to match on. The special value "*" matches all local names.

Returns:
A new DOM_NodeList object containing all the matched DOM_Elements.

DOMString DOM_Element::getTagName ( ) const

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.

bool DOM_Element::hasAttribute ( const DOMString & name ) const

Returns true when an attribute with a given name is specified on this element or has a default value, false otherwise.
Parameters:

name The name of the attribute to look for.

Returns:
true if an attribute with the given name is specified on this element or has a default value, false otherwise.

bool DOM_Element::hasAttributeNS ( const DOMString & namespaceURI,

const DOMString & localName

) const

Returns true when an attribute with a given local name and namespace URI is specified on this element or has a default value, false otherwise. HTML-only DOM implementations do not need to implement this method.
Parameters:

namespaceURI The namespace URI of the attribute to look for.

localName The local name of the attribute to look for.

Returns:
true if an attribute with the given local name and namespace URI is specified or has a default value on this element, false otherwise.

Since:
DOM Level 2

bool DOM_Element::hasAttributes ( ) const

Returns whether this node (if it is an element) has any attributes.
Returns:
true if this node has any attributes, false otherwise.

Reimplemented from DOM_Node.

DOM_Element & DOM_Element::operator= ( const DOM_NullPtr * val )

Assignment operator. This overloaded variant is provided for the sole purpose of setting a DOM_Node reference variable to zero. Nulling out a reference variable in this way will decrement the reference count on the underlying Node object that the variable formerly referenced. This effect is normally obtained when reference variable goes out of scope, but zeroing them can be useful for global instances, or for local instances that will remain in scope for an extended time, when the storage belonging to the underlying node needs to be reclaimed.

Parameters:

val Only a value of 0, or null, is allowed.

Reimplemented from DOM_Node.

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

Assignment operator.

Parameters:

other The object to be copied.

void DOM_Element::removeAttribute ( const DOMString & name )

Removes an attribute by name.
If the removed attribute is known to have a default value, an attribute immediately appears containing the default value as well as the corresponding namespace URI, local name, and prefix when applicable.
To remove an attribute by local name and namespace URI, use the removeAttributeNS method.
Parameters:

name The name of the attribute to remove.

Exceptions:

DOMException NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.

DOM_Attr DOM_Element::removeAttributeNode ( DOM_Attr oldAttr )

Removes the specified attribute node. If the removed DOM_Attr has a default value it is immediately replaced. The replacing attribute has the same namespace URI and local name, as well as the original prefix, when applicable.

Parameters:

oldAttr The DOM_Attr node to remove from the attribute list.

Returns:
The DOM_Attr node that was removed.

Exceptions:

DOMException NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
NOT_FOUND_ERR: Raised if oldAttr is not an attribute of the element.

void DOM_Element::removeAttributeNS ( const DOMString & namespaceURI,

const DOMString & localName

)

Removes an attribute by local name and namespace URI. If the removed attribute has a default value it is immediately replaced. The replacing attribute has the same namespace URI and local name, as well as the original prefix.

Parameters:

namespaceURI The namespace URI of the attribute to remove.

localName The local name of the attribute to remove.

Exceptions:

DOMException NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.

void DOM_Element::setAttribute ( const DOMString & name,

const DOMString & 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. In order to assign an attribute value that contains entity references, the user must create an DOM_Attr node plus any Text and EntityReference nodes, build the appropriate subtree, and use setAttributeNode to assign it as the value of an attribute.
Parameters:

name The name of the attribute to create or alter.

value Value to set in string form.

Exceptions:

DOMException INVALID_CHARACTER_ERR: Raised if the specified name contains an illegal character.
NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.

DOM_Attr DOM_Element::setAttributeNode ( DOM_Attr newAttr )

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

newAttr The DOM_Attr node to add to the attribute list.

Returns:
If the newAttr attribute replaces an existing attribute, the replaced DOM_Attr node is returned, otherwise null is returned.

Exceptions:

DOMException WRONG_DOCUMENT_ERR: Raised if newAttr was created from a different document than the one that created the element.
NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
INUSE_ATTRIBUTE_ERR: Raised if newAttr is already an attribute of another DOM_Element object. The DOM user must explicitly clone DOM_Attr nodes to re-use them in other elements.

DOM_Attr DOM_Element::setAttributeNodeNS ( DOM_Attr newAttr )

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

Parameters:

newAttr The DOM_Attr node to add to the attribute list.

Returns:
If the newAttr attribute replaces an existing attribute with the same local name and namespace URI, the replaced DOM_Attr node is returned, otherwise null is returned.

Exceptions:

DOMException WRONG_DOCUMENT_ERR: Raised if newAttr was created from a different document than the one that created the element.
NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
INUSE_ATTRIBUTE_ERR: Raised if newAttr is already an attribute of another DOM_Element object. The DOM user must explicitly clone DOM_Attr nodes to re-use them in other elements.

void DOM_Element::setAttributeNS ( const DOMString & namespaceURI,

const DOMString & qualifiedName,

const DOMString & value

)

Adds a new attribute. If an attribute with the same local name and namespace URI is already present on the element, its prefix is changed to be the prefix part of the qualifiedName, and its value is changed to be 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. In order to assign an attribute value that contains entity references, the user must create an DOM_Attr node plus any DOM_Text and DOM_EntityReference nodes, build the appropriate subtree, and use setAttributeNodeNS or setAttributeNode to assign it as the value of an attribute.

Parameters:

namespaceURI The namespace URI of the attribute to create or alter.

qualifiedName The qualified name of the attribute to create or alter.

value The value to set in string form.

Exceptions:

DOMException INVALID_CHARACTER_ERR: Raised if the specified qualified name contains an illegal character.
NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
NAMESPACE_ERR: Raised if the qualifiedName is malformed, if the qualifiedName has a prefix and the namespaceURI is null or an empty string, if the qualifiedName has a prefix that is "xml" and the namespaceURI is different from "http://www.w3.org/XML/1998/namespace", if the qualifiedName has a prefix that is "xmlns" and the namespaceURI is different from "http://www.w3.org/2000/xmlns/", or if the qualifiedName is "xmlns" and the namespaceURI is different from "http://www.w3.org/2000/xmlns/".

The documentation for this class was generated from the following files:

DOM_Element.hpp
DOM_Element.cpp

Generated on Tue Nov 19 09:36:38 2002 by

1.3-rc1

DOM_Element Class Reference

Public Methods

Protected Methods

Friends

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation