com.ibm.xml.dom
Class AttrImpl

java.lang.Object
  |
  +--com.ibm.xml.dom.NodeImpl
        |
        +--com.ibm.xml.dom.AttrImpl

Direct Known Subclasses:

DeferredAttrImpl

public class AttrImpl

extends NodeImpl

implements Attr

Attribute represents an XML-style attribute of an Element. Typically, the allowable values are controlled by its declaration in the Document Type Definition (DTD) governing this kind of document.

If the attribute has not been explicitly assigned a value, but has been declared in the DTD, it will exist and have that default. Only if neither the document nor the DTD specifies a value will the Attribute really be considered absent and have no value; in that case, querying the attribute will return null.

Attributes may have multiple children that contain their data. (XML allows attributes to contain entity references, and tokenized attribute types such as NMTOKENS may have a child for each token.) For convenience, the Attribute object's getValue() method returns the string version of the attribute's value.

Attributes are not children of the Elements they belong to, in the usual sense, and have no valid Parent reference. However, the spec says they _do_ belong to a specific Element, and an INUSE exception is to be thrown if the user attempts to explicitly share them between elements.

Note that Elements do not permit attributes to appear to be shared (see the INUSE exception), so this object's mutability is officially not an issue.

Note: Attributes do not have parent nodes. In other words, the getParentNode() method is defined to return null for Attr nodes. However, the getElement() method will return the element node that this attribute is associated with.

Since:

PR-DOM-Level-1-19980818.

Version:

Revision: 50 1.7 src/com/ibm/xml/dom/AttrImpl.java, parser, xml4j2, xml4j2_0_15

See Also:

Serialized Form

Field Summary

protected boolean	owned Flag used for INUSE exception processing.
protected boolean	specified False for default attributes.

Fields inherited from class com.ibm.xml.dom.NodeImpl

ELEMENT_DEFINITION_NODE, firstChild, kidOK, lastChild, name, nextSibling, ownerDocument, parentNode, previousSibling, readOnly, syncChildren, syncData, userData, value

Constructor Summary

AttrImpl(DocumentImpl ownerDocument, java.lang.String name)
Attribute has no public constructor.

Method Summary

Element	getElement() Deprecated. Previous working draft of DOM Level 2. New method is getOwnerElement().
java.lang.String	getName() In Attributes, NodeName is considered a synonym for the attribute's Name
short	getNodeType() A short integer indicating what type of node this is.
java.lang.String	getNodeValue() In Attribute objects, NodeValue is considered a synonym for Value.
Element	getOwnerElement() Returns the element node that this attribute is associated with, or null if the attribute has not been added to an element.
Node	getParentNode() Attributes don't have parent nodes.
boolean	getSpecified() The "specified" flag is true if and only if this attribute's value was explicitly specified in the original document.
java.lang.String	getValue() The "string value" of an Attribute is its text representation, which in turn is a concatenation of the string values of its children.
void	setNodeValue(java.lang.String value) Implicit in the rerouting of getNodeValue to getValue is the need to redefine setNodeValue, for symmetry's sake.
void	setSpecified(boolean arg) NON-DOM, for use by parser
void	setValue(java.lang.String value) The DOM doesn't clearly define what setValue(null) means.
java.lang.String	toString() NON-DOM method for debugging convenience

Methods inherited from class com.ibm.xml.dom.NodeImpl

appendChild, changed, cloneNode, getAttributes, getChildNodes, getFirstChild, getLastChild, getLength, getNextSibling, getNodeName, getOwnerDocument, getPreviousSibling, getReadOnly, getUserData, hasChildNodes, insertBefore, isKidOK, item, removeChild, replaceChild, setReadOnly, setUserData, synchronizeChildren, synchronizeData

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

owned

protected boolean owned

Flag used for INUSE exception processing.

specified

protected boolean specified

False for default attributes.

Constructor Detail

AttrImpl

public AttrImpl(DocumentImpl ownerDocument,
                java.lang.String name)

Attribute has no public constructor. Please use the factory method in the Document class.

Method Detail

getNodeType

public short getNodeType()

A short integer indicating what type of node this is. The named constants for this value are defined in the org.w3c.dom.Node interface.

Overrides:

getNodeType in class NodeImpl

setNodeValue

public void setNodeValue(java.lang.String value)
                  throws DOMException

Implicit in the rerouting of getNodeValue to getValue is the need to redefine setNodeValue, for symmetry's sake. Note that since we're explicitly providing a value, Specified should be set true.... even if that value equals the default.

Overrides:

setNodeValue in class NodeImpl

getNodeValue

public java.lang.String getNodeValue()

In Attribute objects, NodeValue is considered a synonym for Value.

Overrides:

getNodeValue in class NodeImpl

See Also:

getValue()

getParentNode

public Node getParentNode()

Attributes don't have parent nodes.

Overrides:

getParentNode in class NodeImpl

getName

public java.lang.String getName()

In Attributes, NodeName is considered a synonym for the attribute's Name

Specified by:

getName in interface Attr

setValue

public void setValue(java.lang.String value)

The DOM doesn't clearly define what setValue(null) means. I've taken it as "remove all children", which from outside should appear similar to setting it to the empty string.

Specified by:

setValue in interface Attr

getValue

public java.lang.String getValue()

The "string value" of an Attribute is its text representation, which in turn is a concatenation of the string values of its children.

Specified by:

getValue in interface Attr

getSpecified

public boolean getSpecified()

The "specified" flag is true if and only if this attribute's value was explicitly specified in the original document. Note that the implementation, not the user, is in charge of this property. If the user asserts an Attribute value (even if it ends up having the same value as the default), it is considered a specified attribute. If you really want to revert to the default, delete the attribute from the Element, and the Implementation will re-assert the default (if any) in its place, with the appropriate specified=false setting.

Specified by:

getSpecified in interface Attr

getElement

public Element getElement()

Deprecated. Previous working draft of DOM Level 2. New method is getOwnerElement().

Returns the element node that this attribute is associated with, or null if the attribute has not been added to an element.

See Also:

getOwnerElement()

getOwnerElement

public Element getOwnerElement()

Returns the element node that this attribute is associated with, or null if the attribute has not been added to an element.

Since:

WD-DOM-Level-2-19990719

setSpecified

public void setSpecified(boolean arg)

NON-DOM, for use by parser

toString

public java.lang.String toString()

NON-DOM method for debugging convenience

Overrides:

toString in class NodeImpl