Interface Attr
- All Superinterfaces:
- Node
Attr interface represents an attribute in an
 Element object. Typically the allowable values for the
 attribute are defined in a schema associated with the document.
 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 Node.nodeValue
 attribute on the Attr instance can also be used to retrieve
 the string version of the attribute's value(s).
 
 If the attribute was not explicitly given a value in the instance
 document but has a default value provided by the schema associated with
 the document, an attribute node will be created with
 specified set to false. Removing attribute
 nodes for which a default value is defined in the schema generates a new
 attribute node with the default value and specified set to
 false. If validation occurred while invoking
 Document.normalizeDocument(), attribute nodes with
 specified equals to false are recomputed
 according to the default attribute values provided by the schema. If no
 default value is associate with this attribute in the schema, the
 attribute node is discarded.
 
In XML, where the value of an attribute can contain entity references,
 the child nodes of the Attr node may be either
 Text or EntityReference nodes (when these are
 in use; see the description of EntityReference for
 discussion).
 
The DOM Core represents all attribute values as simple strings, even if the DTD or schema associated with the document declares them of some specific type such as tokenized.
The way attribute value normalization is performed by the DOM
 implementation depends on how much the implementation knows about the
 schema in use. Typically, the value and
 nodeValue attributes of an Attr node initially
 returns the normalized value given by the parser. It is also the case
 after Document.normalizeDocument() is called (assuming the
 right options have been set). But this may not be the case after
 mutation, independently of whether the mutation is performed by setting
 the string value directly or by changing the Attr child
 nodes. In particular, this is true when character
 references are involved, given that they are not represented in the DOM and they
 impact attribute value normalization. On the other hand, if the
 implementation knows about the schema in use when the attribute value is
 changed, and it is of a different type than CDATA, it may normalize it
 again at that time. This is especially true of specialized DOM
 implementations, such as SVG DOM implementations, which store attribute
 values in an internal form different from a string.
 
The following table gives some examples of the relations between the attribute value in the original document (parsed attribute), the value as exposed in the DOM, and the serialization of the value:
| Examples | Parsed attribute value | Initial Attr.value | Serialized attribute value | 
|---|---|---|---|
| Character reference | "x²=5" | "x²=5" | "x²=5" | 
| Built-in character entity | "y<6" | "y<6" | "y<6" | 
| Literal newline between | "x=5
y=6" | "x=5 y=6" | "x=5
y=6" | 
| Normalized newline between | "x=5 y=6" | "x=5 y=6" | "x=5 y=6" | 
| Entity ewith literal newline | <!ENTITY e '...
...'> [...]> "x=5&e;y=6" | Dependent on Implementation and Load Options | Dependent on Implementation and Load/Save Options | 
See also the Document Object Model (DOM) Level 3 Core Specification.
- Since:
- 1.4, DOM Level 2
- 
Field SummaryFields declared in interface org.w3c.dom.NodeATTRIBUTE_NODE, CDATA_SECTION_NODE, COMMENT_NODE, DOCUMENT_FRAGMENT_NODE, DOCUMENT_NODE, DOCUMENT_POSITION_CONTAINED_BY, DOCUMENT_POSITION_CONTAINS, DOCUMENT_POSITION_DISCONNECTED, DOCUMENT_POSITION_FOLLOWING, DOCUMENT_POSITION_IMPLEMENTATION_SPECIFIC, DOCUMENT_POSITION_PRECEDING, DOCUMENT_TYPE_NODE, ELEMENT_NODE, ENTITY_NODE, ENTITY_REFERENCE_NODE, NOTATION_NODE, PROCESSING_INSTRUCTION_NODE, TEXT_NODE
- 
Method SummaryModifier and TypeMethodDescriptiongetName()Returns the name of this attribute.TheElementnode this attribute is attached to ornullif this attribute is not in use.The type information associated with this attribute.booleanTrueif this attribute was explicitly given a value in the instance document,falseotherwise.getValue()On retrieval, the value of the attribute is returned as a string.booleanisId()Returns whether this attribute is known to be of type ID (i.e. to contain an identifier for its owner element) or not.voidOn retrieval, the value of the attribute is returned as a string.Methods declared in interface org.w3c.dom.NodeappendChild, cloneNode, compareDocumentPosition, getAttributes, getBaseURI, getChildNodes, getFeature, getFirstChild, getLastChild, getLocalName, getNamespaceURI, getNextSibling, getNodeName, getNodeType, getNodeValue, getOwnerDocument, getParentNode, getPrefix, getPreviousSibling, getTextContent, getUserData, hasAttributes, hasChildNodes, insertBefore, isDefaultNamespace, isEqualNode, isSameNode, isSupported, lookupNamespaceURI, lookupPrefix, normalize, removeChild, replaceChild, setNodeValue, setPrefix, setTextContent, setUserData
- 
Method Details- 
getNameString getName()Returns the name of this attribute. IfNode.localNameis different fromnull, this attribute is a qualified name.
- 
getSpecifiedboolean getSpecified()Trueif this attribute was explicitly given a value in the instance document,falseotherwise. If the application changed the value of this attribute node (even if it ends up having the same value as the default value) then it is set totrue. The implementation may handle attributes with default values from other schemas similarly but applications should useDocument.normalizeDocument()to guarantee this information is up-to-date.
- 
getValueString getValue()On retrieval, the value of the attribute is returned as a string. Character and general entity references are replaced with their values. See also the methodgetAttributeon theElementinterface.
 On setting, this creates aTextnode with the unparsed contents of the string, i.e. any characters that an XML processor would recognize as markup are instead treated as literal text. See also the methodElement.setAttribute().
 Some specialized implementations, such as some [SVG 1.1] implementations, may do normalization automatically, even after mutation; in such case, the value on retrieval may differ from the value on setting.
- 
setValueOn retrieval, the value of the attribute is returned as a string. Character and general entity references are replaced with their values. See also the methodgetAttributeon theElementinterface.
 On setting, this creates aTextnode with the unparsed contents of the string, i.e. any characters that an XML processor would recognize as markup are instead treated as literal text. See also the methodElement.setAttribute().
 Some specialized implementations, such as some [SVG 1.1] implementations, may do normalization automatically, even after mutation; in such case, the value on retrieval may differ from the value on setting.- Throws:
- DOMException- NO_MODIFICATION_ALLOWED_ERR: Raised when the node is readonly.
 
- 
getOwnerElementElement getOwnerElement()TheElementnode this attribute is attached to ornullif this attribute is not in use.- Since:
- 1.4, DOM Level 2
 
- 
getSchemaTypeInfoTypeInfo getSchemaTypeInfo()The type information associated with this attribute. While the type information contained in this attribute is guarantee to be correct after loading the document or invokingDocument.normalizeDocument(),schemaTypeInfomay not be reliable if the node was moved.- Since:
- 1.5, DOM Level 3
 
- 
isIdboolean isId()Returns whether this attribute is known to be of type ID (i.e. to contain an identifier for its owner element) or not. When it is and its value is unique, theownerElementof this attribute can be retrieved using the methodDocument.getElementById. The implementation could use several ways to determine if an attribute node is known to contain an identifier:-  If validation
 occurred using an XML Schema [XML Schema Part 1]
  while loading the document or while invoking
 Document.normalizeDocument(), the post-schema-validation infoset contributions (PSVI contributions) values are used to determine if this attribute is a schema-determined ID attribute using the schema-determined ID definition in [XPointer] .
-  If validation occurred using a DTD while loading the document or
 while invoking Document.normalizeDocument(), the infoset [type definition] value is used to determine if this attribute is a DTD-determined ID attribute using the DTD-determined ID definition in [XPointer] .
-  from the use of the methods Element.setIdAttribute(),Element.setIdAttributeNS(), orElement.setIdAttributeNode(), i.e. it is an user-determined ID attribute;Note: XPointer framework (see section 3.2 in [XPointer] ) consider the DOM user-determined ID attribute as being part of the XPointer externally-determined ID definition. 
- using mechanisms that are outside the scope of this specification, it is then an externally-determined ID attribute. This includes using schema languages different from XML schema and DTD.
 
 If validation occurred while invokingDocument.normalizeDocument(), all user-determined ID attributes are reset and all attribute nodes ID information are then reevaluated in accordance to the schema used. As a consequence, if theAttr.schemaTypeInfoattribute contains an ID type,isIdwill always return true.- Since:
- 1.5, DOM Level 3
 
-  If validation
 occurred using an XML Schema [XML Schema Part 1]
  while loading the document or while invoking
 
 
-