AttrImpl (Xerces2 Java 2.11.1 API)

java.lang.Object
- org.apache.xerces.dom.NodeImpl
- - org.apache.xerces.dom.AttrImpl

All Implemented Interfaces:

Serializable, Cloneable, Attr, EventTarget, Node, NodeList, TypeInfo

Direct Known Subclasses:

AttrNSImpl, DeferredAttrImpl
```
public class AttrImpl
extends NodeImpl
implements Attr, TypeInfo
```
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: The ownerNode attribute is used to store the Element the Attr node is associated with. Attr nodes do not have parent nodes. Besides, the getOwnerElement() method can be used to get the element node this attribute is associated with.
AttrImpl does not support Namespaces. AttrNSImpl, which inherits from it, does.
AttrImpl used to inherit from ParentNode. It now directly inherits from NodeImpl and provide its own implementation of the ParentNode's behavior. The reason is that we now try and avoid to always create a Text node to hold the value of an attribute. The DOM spec requires it, so we still have to do it in case getFirstChild() is called for instance. The reason attribute values are stored as a list of nodes is so that they can carry more than a simple string. They can also contain EntityReference nodes. However, most of the times people only have a single string that they only set and get through Element.set/getAttribute or Attr.set/getValue. In this new version, the Attr node has a value pointer which can either be the String directly or a pointer to the first ChildNode. A flag tells which one it currently is. Note that while we try to stick with the direct String as much as possible once we've switched to a node there is no going back. This is because we have no way to know whether the application keeps referring to the node we once returned.
The gain in memory varies on the density of attributes in the document. But in the tests I've run I've seen up to 12% of memory gain. And the good thing is that it also leads to a slight gain in speed because we allocate fewer objects! I mean, that's until we have to actually create the node...
To avoid too much duplicated code, I got rid of ParentNode and renamed ChildAndParentNode, which I never really liked, to ParentNode for simplicity, this doesn't make much of a difference in memory usage because there are only very few objects that are only a Parent. This is only true now because AttrImpl now inherits directly from NodeImpl and has its own implementation of the ParentNode's node behavior. So there is still some duplicated code there.
This class doesn't directly support mutation events, however, it notifies the document when mutations are performed so that the document class do so.
WARNING: Some of the code here is partially duplicated in ParentNode, be careful to keep these two classes in sync!

Since:

PR-DOM-Level-1-19980818.

Version:

$Id$

Author:

Arnaud Le Hors, IBM, Joe Kesselman, IBM, Andy Clark, IBM

See Also:
AttrNSImpl, Serialized Form

Field Summary

Fields
Modifier and Type Field and Description

protected String name
Attribute name.

protected Object value
This can either be a String or the first child node.
- Fields inherited from class org.apache.xerces.dom.NodeImpl
  DOCUMENT_POSITION_CONTAINS, DOCUMENT_POSITION_DISCONNECTED, DOCUMENT_POSITION_FOLLOWING, DOCUMENT_POSITION_IMPLEMENTATION_SPECIFIC, DOCUMENT_POSITION_IS_CONTAINED, DOCUMENT_POSITION_PRECEDING, ELEMENT_DEFINITION_NODE, FIRSTCHILD, flags, HASSTRING, ID, IGNORABLEWS, NORMALIZED, OWNED, ownerNode, READONLY, SPECIFIED, SYNCCHILDREN, SYNCDATA, TREE_POSITION_ANCESTOR, TREE_POSITION_DESCENDANT, TREE_POSITION_DISCONNECTED, TREE_POSITION_EQUIVALENT, TREE_POSITION_FOLLOWING, TREE_POSITION_PRECEDING, TREE_POSITION_SAME_NODE
- Fields inherited from interface org.w3c.dom.Node
  ATTRIBUTE_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
- Fields inherited from interface org.w3c.dom.TypeInfo
  DERIVATION_EXTENSION, DERIVATION_LIST, DERIVATION_RESTRICTION, DERIVATION_UNION

Fields
Modifier and Type	Field and Description
`protected String`	`name` Attribute name.
`protected Object`	`value` This can either be a String or the first child node.

Constructor Summary

Constructors
Modifier Constructor and Description

protected AttrImpl()

protected AttrImpl(CoreDocumentImpl ownerDocument, String name)
Attribute has no public constructor.

Constructors
Modifier	Constructor and Description
`protected`	`AttrImpl()`
`protected`	`AttrImpl(CoreDocumentImpl ownerDocument, String name)` Attribute has no public constructor.

Method Summary

Methods
Modifier and Type	Method and Description
`Node`	`cloneNode(boolean deep)` Returns a duplicate of a given node.
`NodeList`	`getChildNodes()` Obtain a NodeList enumerating all children of this node.
`Element`	`getElement()` Deprecated. Previous working draft of DOM Level 2. New method is `getOwnerElement()`.
`Node`	`getFirstChild()` The first child of this Node, or null if none.
`Node`	`getLastChild()` The last child of this Node, or null if none.
`int`	`getLength()` NodeList method: Count the immediate children of this node
`String`	`getName()` In Attributes, NodeName is considered a synonym for the attribute's Name
`String`	`getNodeName()` Returns the attribute name
`short`	`getNodeType()` A short integer indicating what type of node this is.
`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.
`TypeInfo`	`getSchemaTypeInfo()` Method getSchemaTypeInfo.
`boolean`	`getSpecified()` The "specified" flag is true if and only if this attribute's value was explicitly specified in the original document.
`String`	`getTypeName()`
`String`	`getTypeNamespace()`
`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.
`boolean`	`hasChildNodes()` Test whether this node has any children.
`Node`	`insertBefore(Node newChild, Node refChild)` Move one or more node(s) to our list of children.
`boolean`	`isDerivedFrom(String typeNamespaceArg, String typeNameArg, int derivationMethod)` Introduced in DOM Level 3.
`boolean`	`isEqualNode(Node arg)` DOM Level 3 WD- Experimental.
`boolean`	`isId()` DOM Level 3: isId
`Node`	`item(int index)` NodeList method: Return the Nth immediate child of this node, or null if the index is out of bounds.
`protected void`	`makeChildNode()`
`void`	`normalize()` Puts all `Text` nodes in the full depth of the sub-tree underneath this `Node`, 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.
`Node`	`removeChild(Node oldChild)` Remove a child from this Node.
`Node`	`replaceChild(Node newChild, Node oldChild)` Make newChild occupy the location that oldChild used to have.
`void`	`setIdAttribute(boolean id)` NON-DOM: set the type of this attribute to be ID type.
`void`	`setNodeValue(String value)` Implicit in the rerouting of getNodeValue to getValue is the need to redefine setNodeValue, for symmetry's sake.
`protected void`	`setOwnerDocument(CoreDocumentImpl doc)` NON-DOM set the ownerDocument of this node and its children
`void`	`setReadOnly(boolean readOnly, boolean deep)` Override default behavior so that if deep is true, children are also toggled.
`void`	`setSpecified(boolean arg)` NON-DOM, for use by parser
`void`	`setType(Object type)` NON-DOM: used by the parser
`void`	`setValue(String newvalue)` The DOM doesn't clearly define what setValue(null) means.
`protected void`	`synchronizeChildren()` Override this method in subclass to hook in efficient internal data structure.
`String`	`toString()` NON-DOM method for debugging convenience

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.w3c.dom.Node
appendChild, compareDocumentPosition, getAttributes, getBaseURI, getFeature, getLocalName, getNamespaceURI, getNextSibling, getOwnerDocument, getParentNode, getPrefix, getPreviousSibling, getTextContent, getUserData, hasAttributes, isDefaultNamespace, isSameNode, isSupported, lookupNamespaceURI, lookupPrefix, setPrefix, setTextContent, setUserData

- Field Detail
  - value
```
protected Object value
```
    This can either be a String or the first child node.
  - name
```
protected String name
```
    Attribute name.
- Constructor Detail
  - AttrImpl
```
protected AttrImpl(CoreDocumentImpl ownerDocument,
        String name)
```
    Attribute has no public constructor. Please use the factory method in the Document class.
  - AttrImpl
```
protected AttrImpl()
```
- Method Detail
  - makeChildNode
```
protected void makeChildNode()
```
  - setOwnerDocument
```
protected void setOwnerDocument(CoreDocumentImpl doc)
```
    NON-DOM set the ownerDocument of this node and its children
    
    Overrides:
    
    setOwnerDocument in class NodeImpl
  - setIdAttribute
```
public void setIdAttribute(boolean id)
```
    NON-DOM: set the type of this attribute to be ID type.
    
    Parameters:
    id -
  - isId
```
public boolean isId()
```
    DOM Level 3: isId
    
    Specified by:
    
    isId in interface Attr
  - cloneNode
```
public Node cloneNode(boolean deep)
```
    Description copied from class: NodeImpl
    
    Returns a duplicate of a given node. You can consider this a generic "copy constructor" for nodes. The newly returned object should be completely independent of the source object's subtree, so changes in one after the clone has been made will not affect the other.
    Note: since we never have any children deep is meaningless here, ParentNode overrides this behavior.
    
    Specified by:
    
    cloneNode in interface Node
    
    Overrides:
    
    cloneNode in class NodeImpl
    
    See Also:
    Example: Cloning a Text node will copy both the node and the text it contains. Example: Cloning something that has children -- Element or Attr, for example -- will _not_ clone those children unless a "deep clone" has been requested. A shallow clone of an Attr node will yield an empty Attr of the same name.
    NOTE: Clones will always be read/write, even if the node being cloned is read-only, to permit applications using only the DOM API to obtain editable copies of locked portions of the tree.
  - 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.
    
    Specified by:
    
    getNodeType in interface Node
    
    Specified by:
    
    getNodeType in class NodeImpl
  - getNodeName
```
public String getNodeName()
```
    Returns the attribute name
    
    Specified by:
    
    getNodeName in interface Node
    
    Specified by:
    
    getNodeName in class NodeImpl
  - setNodeValue
```
public void setNodeValue(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.
    
    Specified by:
    
    setNodeValue in interface Node
    
    Overrides:
    
    setNodeValue in class NodeImpl
    
    Throws:
    
    DOMException
  - getTypeName
```
public String getTypeName()
```
    Specified by:
    
    getTypeName in interface TypeInfo
    
    See Also:
    TypeInfo.getTypeName()
  - getTypeNamespace
```
public String getTypeNamespace()
```
    Specified by:
    
    getTypeNamespace in interface TypeInfo
    
    See Also:
    TypeInfo.getTypeNamespace()
  - getSchemaTypeInfo
```
public TypeInfo getSchemaTypeInfo()
```
    Method getSchemaTypeInfo.
    
    Specified by:
    
    getSchemaTypeInfo in interface Attr
    
    Returns:
    TypeInfo
  - getNodeValue
```
public String getNodeValue()
```
    In Attribute objects, NodeValue is considered a synonym for Value.
    
    Specified by:
    
    getNodeValue in interface Node
    
    Overrides:
    
    getNodeValue in class NodeImpl
    
    See Also:
    getValue()
  - getName
```
public String getName()
```
    In Attributes, NodeName is considered a synonym for the attribute's Name
    
    Specified by:
    
    getName in interface Attr
  - setValue
```
public void setValue(String newvalue)
```
    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 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.
    
    Specified by:
    
    getOwnerElement in interface Attr
    
    Since:
    
    WD-DOM-Level-2-19990719
  - normalize
```
public void normalize()
```
    Description copied from class: NodeImpl
    
    Puts all Text nodes in the full depth of the sub-tree underneath this Node, 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.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.
    Note that this implementation simply calls normalize() on this Node's children. It is up to implementors or Node to override normalize() to take action.
    
    Specified by:
    
    normalize in interface Node
    
    Overrides:
    
    normalize in class NodeImpl
  - setSpecified
```
public void setSpecified(boolean arg)
```
    NON-DOM, for use by parser
  - setType
```
public void setType(Object type)
```
    NON-DOM: used by the parser
    
    Parameters:
    type -
  - toString
```
public String toString()
```
    NON-DOM method for debugging convenience
    
    Overrides:
    
    toString in class NodeImpl
  - hasChildNodes
```
public boolean hasChildNodes()
```
    Test whether this node has any children. Convenience shorthand for (Node.getFirstChild()!=null)
    
    Specified by:
    
    hasChildNodes in interface Node
    
    Overrides:
    
    hasChildNodes in class NodeImpl
    
    See Also:
    ParentNode
  - getChildNodes
```
public NodeList getChildNodes()
```
    Obtain a NodeList enumerating all children of this node. If there are none, an (initially) empty NodeList is returned.
    NodeLists are "live"; as children are added/removed the NodeList will immediately reflect those changes. Also, the NodeList refers to the actual nodes, so changes to those nodes made via the DOM tree will be reflected in the NodeList and vice versa.
    In this implementation, Nodes implement the NodeList interface and provide their own getChildNodes() support. Other DOMs may solve this differently.
    
    Specified by:
    
    getChildNodes in interface Node
    
    Overrides:
    
    getChildNodes in class NodeImpl
  - getFirstChild
```
public Node getFirstChild()
```
    The first child of this Node, or null if none.
    
    Specified by:
    
    getFirstChild in interface Node
    
    Overrides:
    
    getFirstChild in class NodeImpl
    
    See Also:
    ParentNode
  - getLastChild
```
public Node getLastChild()
```
    The last child of this Node, or null if none.
    
    Specified by:
    
    getLastChild in interface Node
    
    Overrides:
    
    getLastChild in class NodeImpl
    
    See Also:
    ParentNode
  - insertBefore
```
public Node insertBefore(Node newChild,
                Node refChild)
                  throws DOMException
```
    Move one or more node(s) to our list of children. Note that this implicitly removes them from their previous parent.
    
    Specified by:
    
    insertBefore in interface Node
    
    Overrides:
    
    insertBefore in class NodeImpl
    
    Parameters:
    newChild - The Node to be moved to our subtree. As a convenience feature, inserting a DocumentNode will instead insert all its children.
    refChild - Current child which newChild should be placed immediately before. If refChild is null, the insertion occurs after all existing Nodes, like appendChild().
    
    Returns:
    newChild, in its new state (relocated, or emptied in the case of DocumentNode.)
    
    Throws:
    
    DOMException(HIERARCHY_REQUEST_ERR) - if newChild is of a type that shouldn't be a child of this node, or if newChild is an ancestor of this node.
    
    DOMException(WRONG_DOCUMENT_ERR) - if newChild has a different owner document than we do.
    
    DOMException(NOT_FOUND_ERR) - if refChild is not a child of this node.
    
    DOMException(NO_MODIFICATION_ALLOWED_ERR) - if this node is read-only.
    
    DOMException
    See Also:
    ParentNode
  - removeChild
```
public Node removeChild(Node oldChild)
                 throws DOMException
```
    Remove a child from this Node. The removed child's subtree remains intact so it may be re-inserted elsewhere.
    
    Specified by:
    
    removeChild in interface Node
    
    Overrides:
    
    removeChild in class NodeImpl
    
    Returns:
    oldChild, in its new state (removed).
    
    Throws:
    
    DOMException(NOT_FOUND_ERR) - if oldChild is not a child of this node.
    
    DOMException(NO_MODIFICATION_ALLOWED_ERR) - if this node is read-only.
    
    DOMException
    See Also:
    ParentNode
  - replaceChild
```
public Node replaceChild(Node newChild,
                Node oldChild)
                  throws DOMException
```
    Make newChild occupy the location that oldChild used to have. Note that newChild will first be removed from its previous parent, if any. Equivalent to inserting newChild before oldChild, then removing oldChild.
    
    Specified by:
    
    replaceChild in interface Node
    
    Overrides:
    
    replaceChild in class NodeImpl
    
    Returns:
    oldChild, in its new state (removed).
    
    Throws:
    
    DOMException(HIERARCHY_REQUEST_ERR) - if newChild is of a type that shouldn't be a child of this node, or if newChild is one of our ancestors.
    
    DOMException(WRONG_DOCUMENT_ERR) - if newChild has a different owner document than we do.
    
    DOMException(NOT_FOUND_ERR) - if oldChild is not a child of this node.
    
    DOMException(NO_MODIFICATION_ALLOWED_ERR) - if this node is read-only.
    
    DOMException
    See Also:
    ParentNode
  - getLength
```
public int getLength()
```
    NodeList method: Count the immediate children of this node
    
    Specified by:
    
    getLength in interface NodeList
    
    Overrides:
    
    getLength in class NodeImpl
    
    Returns:
    int
    See Also:
    ParentNode
  - item
```
public Node item(int index)
```
    NodeList method: Return the Nth immediate child of this node, or null if the index is out of bounds.
    
    Specified by:
    
    item in interface NodeList
    
    Overrides:
    
    item in class NodeImpl
    
    Parameters:
    index - int
    
    Returns:
    org.w3c.dom.Node
    See Also:
    ParentNode
  - isEqualNode
```
public boolean isEqualNode(Node arg)
```
    DOM Level 3 WD- Experimental. Override inherited behavior from ParentNode to support deep equal. isEqualNode is always deep on Attr nodes.
    
    Specified by:
    
    isEqualNode in interface Node
    
    Overrides:
    
    isEqualNode in class NodeImpl
    
    Parameters:
    arg - The node to compare equality with.
    
    Returns:
    If the nodes, and possibly subtrees are equal, true otherwise false.
  - isDerivedFrom
```
public boolean isDerivedFrom(String typeNamespaceArg,
                    String typeNameArg,
                    int derivationMethod)
```
    Introduced in DOM Level 3.
    Checks if a type is derived from another by restriction. See: http://www.w3.org/TR/DOM-Level-3-Core/core.html#TypeInfo-isDerivedFrom
    
    Specified by:
    
    isDerivedFrom in interface TypeInfo
    
    Parameters:
    typeNamespaceArg - The namspace of the ancestor type declaration
    typeNameArg - The name of the ancestor type declaration
    derivationMethod - The derivation method
    
    Returns:
    boolean True if the type is derived by restriciton for the reference type
  - setReadOnly
```
public void setReadOnly(boolean readOnly,
               boolean deep)
```
    Override default behavior so that if deep is true, children are also toggled.
    
    Overrides:
    
    setReadOnly in class NodeImpl
    
    Parameters:
    readOnly - True or false as desired.
    deep - If true, children are also toggled. Note that this will not change the state of an EntityReference or its children, which are always read-only.
    See Also:
    Note: this will not change the state of an EntityReference or its children, which are always read-only.
  - synchronizeChildren
```
protected void synchronizeChildren()
```
    Override this method in subclass to hook in efficient internal data structure.

Class AttrImpl

Field Summary

Fields inherited from class org.apache.xerces.dom.NodeImpl

Fields inherited from interface org.w3c.dom.Node

Fields inherited from interface org.w3c.dom.TypeInfo

Constructor Summary

Method Summary

Methods inherited from class org.apache.xerces.dom.NodeImpl

Methods inherited from class java.lang.Object

Methods inherited from interface org.w3c.dom.Node

Field Detail

value

name

Constructor Detail

AttrImpl

AttrImpl

Method Detail

makeChildNode

setOwnerDocument

setIdAttribute

isId

cloneNode

getNodeType

getNodeName

setNodeValue

getTypeName

getTypeNamespace

getSchemaTypeInfo

getNodeValue

getName

setValue

getValue

getSpecified

getElement

getOwnerElement

normalize

setSpecified

setType

toString

hasChildNodes

getChildNodes

getFirstChild

getLastChild

insertBefore

removeChild

replaceChild

getLength

item

isEqualNode

isDerivedFrom

setReadOnly

synchronizeChildren