KHTML
DOM::Attr Class Reference
TheAttr
interface represents an attribute in an Element
object.
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#include <dom_element.h>
Public Member Functions | |
Attr (const Attr &other) | |
Attr (const Node &other) | |
Attr () | |
DOMString | name () const |
Attr & | operator= (const Attr &other) |
Attr & | operator= (const Node &other) |
Element | ownerElement () const |
void | setValue (const DOMString &) |
bool | specified () const |
DOMString | value () const |
~Attr () | |
Protected Member Functions | |
Attr (AttrImpl *_impl) |
Detailed Description
TheAttr
interface represents an attribute in an Element
object.
Typically the allowable values for the attribute are defined in a document type definition.
Attr
objects inherit the Node
interface, but since they are not actually child nodes of the element they describe, the DOM does not consider them part of the document tree. Thus, the Node
attributes parentNode
, previousSibling
, and nextSibling
have a null value for Attr
objects. The DOM takes the view that attributes are properties of elements rather than having a separate identity from the elements they are associated with; this should make it more efficient to implement such features as default attributes associated with all elements of a given type. Furthermore, Attr
nodes may not be immediate children of a DocumentFragment
. However, they can be associated with Element
nodes contained within a DocumentFragment
. In short, users and implementors of the DOM need to be aware that Attr
nodes have some things in common with other objects inheriting the Node
interface, but they also are quite distinct.
The attribute's effective value is determined as follows: if this attribute has been explicitly assigned any value, that value is the attribute's effective value; otherwise, if there is a declaration for this attribute, and that declaration includes a default value, then that default value is the attribute's effective value; otherwise, the attribute does not exist on this element in the structure model until it has been explicitly added. Note that the nodeValue
attribute on the Attr
instance can also be used to retrieve the string version of the attribute's value(s).
In XML, where the value of an attribute can contain entity references, the child nodes of the Attr
node provide a representation in which entity references are not expanded. These child nodes may be either Text
or EntityReference
nodes. Because the attribute type may be unknown, there are no tokenized attribute values.
Definition at line 89 of file dom_element.h.
Constructor & Destructor Documentation
Attr::Attr | ( | ) |
Definition at line 30 of file dom_element.cpp.
DOM::Attr::Attr | ( | const Node & | other | ) | [inline] |
Definition at line 101 of file dom_element.h.
Attr::Attr | ( | const Attr & | other | ) |
Definition at line 34 of file dom_element.cpp.
Attr::~Attr | ( | ) |
Definition at line 64 of file dom_element.cpp.
Attr::Attr | ( | AttrImpl * | _impl | ) | [protected] |
Definition at line 38 of file dom_element.cpp.
Member Function Documentation
DOMString Attr::name | ( | ) | const |
Definition at line 58 of file dom_element.cpp.
Element Attr::ownerElement | ( | ) | const |
Introduced in DOM Level 2.
The Element node this attribute is attached to or null if this attribute is not in use.
Definition at line 80 of file dom_element.cpp.
void Attr::setValue | ( | const DOMString & | newValue | ) |
bool Attr::specified | ( | ) | const |
If this attribute was explicitly given a value in the original document, this is true
; otherwise, it is false
.
Note that the implementation is in charge of this attribute, not the user. If the user changes the value of the attribute (even if it ends up having the same value as the default value) then the specified
flag is automatically flipped to true
. To re-specify the attribute as the default value from the DTD, the user must delete the attribute. The implementation will then make a new attribute available with specified
set to false
and the default value (if one exists).
In summary:
- If the attribute has an assigned value in the document then
specified
istrue
, and the value is the assigned value.
- If the attribute has no assigned value in the document and has a default value in the DTD, then
specified
isfalse
, and the value is the default value in the DTD.
- If the attribute has no assigned value in the document and has a value of IMPLIED in the DTD, then the attribute does not appear in the structure model of the document.
Definition at line 74 of file dom_element.cpp.
DOMString Attr::value | ( | ) | const |
On retrieval, the value of the attribute is returned as a string.
Character and general entity references are replaced with their values.
On setting, this creates a Text
node with the unparsed contents of the string.
Definition at line 86 of file dom_element.cpp.
The documentation for this class was generated from the following files: