Class ParentNode
- All Implemented Interfaces:
Serializable
,Cloneable
,EventTarget
,Node
,NodeList
- Direct Known Subclasses:
CoreDocumentImpl
,DocumentFragmentImpl
,DocumentTypeImpl
,ElementDefinitionImpl
,ElementImpl
,EntityImpl
,EntityReferenceImpl
ParentNode, just like NodeImpl, also implements NodeList, so it can return itself in response to the getChildNodes() query. This eliminiates the need for a separate ChildNodeList object. Note that this is an IMPLEMENTATION DETAIL; applications should _never_ assume that this identity exists. On the other hand, subclasses may need to override this, in case of conflicting names. This is the case for the classes HTMLSelectElementImpl and HTMLFormElementImpl of the HTML DOM.
While we have a direct reference to the first child, the last child is stored as the previous sibling of the first child. First child nodes are marked as being so, and getNextSibling hides this fact.
Note: Not all parent nodes actually need to also be a child. At some point we used to have ParentNode inheriting from NodeImpl and another class called ChildAndParentNode that inherited from ChildNode. But due to the lack of multiple inheritance a lot of code had to be duplicated which led to a maintenance nightmare. At the same time only a few nodes (Document, DocumentFragment, Entity, and Attribute) cannot be a child so the gain in memory wasn't really worth it. The only type for which this would be the case is Attribute, but we deal with there in another special way, so this is not applicable.
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 AttrImpl, be careful to keep these two classes in sync!
INTERNAL:
- Usage of this class is not supported. It may be altered or removed at any time.
- Version:
- $Id: ParentNode.java 1399511 2012-10-18 04:10:42Z mrglavas $
- Author:
- Arnaud Le Hors, IBM, Joe Kesselman, IBM, Andy Clark, IBM
- See Also:
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Field Summary
FieldsModifier and TypeFieldDescriptionprotected ChildNode
First child.protected org.apache.xerces.dom.NodeListCache
NodeList cacheprotected CoreDocumentImpl
Owner document.Fields inherited from class org.apache.xerces.dom.ChildNode
nextSibling, previousSibling
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_TYPE_NODE, ELEMENT_NODE, ENTITY_NODE, ENTITY_REFERENCE_NODE, NOTATION_NODE, PROCESSING_INSTRUCTION_NODE, TEXT_NODE
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Constructor Summary
ConstructorsModifierConstructorDescriptionConstructor for serialization.protected
ParentNode
(CoreDocumentImpl ownerDocument) No public constructor; only subclasses of ParentNode should be instantiated, and those normally via a Document's factory methods -
Method Summary
Modifier and TypeMethodDescriptioncloneNode
(boolean deep) Returns a duplicate of a given node.Obtain a NodeList enumerating all children of this node.protected final NodeList
Create a NodeList to access children that is use by subclass elements that have methods named getLength() or item(int).The first child of this Node, or null if none.The last child of this Node, or null if none.int
NodeList method: Count the immediate children of this nodeFind the Document that this Node belongs to (the document in whose context the Node was created).This attribute returns the text content of this node and its descendants.boolean
Test whether this node has any children.insertBefore
(Node newChild, Node refChild) Move one or more node(s) to our list of children.boolean
isEqualNode
(Node arg) DOM Level 3 WD- Experimental.item
(int index) NodeList method: Return the Nth immediate child of this node, or null if the index is out of bounds.void
Override default behavior to call normalize() on this Node's children.removeChild
(Node oldChild) Remove a child from this Node.replaceChild
(Node newChild, Node oldChild) Make newChild occupy the location that oldChild used to have.protected void
NON-DOM set the ownerDocument of this node and its childrenvoid
setReadOnly
(boolean readOnly, boolean deep) Override default behavior so that if deep is true, children are also toggled.void
setTextContent
(String textContent) This attribute returns the text content of this node and its descendants.protected void
Override this method in subclass to hook in efficient internal data structure.Methods inherited from class org.apache.xerces.dom.ChildNode
getNextSibling, getParentNode, getPreviousSibling
Methods inherited from class org.apache.xerces.dom.NodeImpl
addEventListener, appendChild, changed, changes, compareDocumentPosition, compareTreePosition, dispatchEvent, getAttributes, getBaseURI, getContainer, getFeature, getLocalName, getNamespaceURI, getNodeName, getNodeNumber, getNodeType, getNodeValue, getPrefix, getReadOnly, getUserData, getUserData, getUserDataRecord, hasAttributes, isDefaultNamespace, isSameNode, isSupported, lookupNamespaceURI, lookupPrefix, needsSyncChildren, removeEventListener, setNodeValue, setPrefix, setUserData, setUserData, synchronizeData, toString
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Field Details
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ownerDocument
Owner document. -
firstChild
First child. -
fNodeListCache
protected transient org.apache.xerces.dom.NodeListCache fNodeListCacheNodeList cache
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Constructor Details
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ParentNode
No public constructor; only subclasses of ParentNode should be instantiated, and those normally via a Document's factory methods -
ParentNode
public ParentNode()Constructor for serialization.
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Method Details
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cloneNode
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.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.
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getOwnerDocument
Find the Document that this Node belongs to (the document in whose context the Node was created). The Node may or may not currently be part of that Document's actual contents.- Specified by:
getOwnerDocument
in interfaceNode
- Overrides:
getOwnerDocument
in classNodeImpl
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setOwnerDocument
NON-DOM set the ownerDocument of this node and its children- Overrides:
setOwnerDocument
in classNodeImpl
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hasChildNodes
public boolean hasChildNodes()Test whether this node has any children. Convenience shorthand for (Node.getFirstChild()!=null)- Specified by:
hasChildNodes
in interfaceNode
- Overrides:
hasChildNodes
in classNodeImpl
- See Also:
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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 interfaceNode
- Overrides:
getChildNodes
in classNodeImpl
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getFirstChild
The first child of this Node, or null if none.- Specified by:
getFirstChild
in interfaceNode
- Overrides:
getFirstChild
in classNodeImpl
- See Also:
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getLastChild
The last child of this Node, or null if none.- Specified by:
getLastChild
in interfaceNode
- Overrides:
getLastChild
in classNodeImpl
- See Also:
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insertBefore
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 interfaceNode
- Overrides:
insertBefore
in classNodeImpl
- 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
- See Also:
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removeChild
Remove a child from this Node. The removed child's subtree remains intact so it may be re-inserted elsewhere.- Specified by:
removeChild
in interfaceNode
- Overrides:
removeChild
in classNodeImpl
- Returns:
- oldChild, in its new state (removed).
- Throws:
DOMException
- See Also:
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replaceChild
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 interfaceNode
- Overrides:
replaceChild
in classNodeImpl
- Returns:
- oldChild, in its new state (removed).
- Throws:
DOMException
- See Also:
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getTextContent
Description copied from class:NodeImpl
This attribute returns the text content of this node and its descendants. When it is defined to be null, setting it has no effect. When set, any possible children this node may have are removed and replaced by a singleText
node containing the string this attribute is set to. On getting, no serialization is performed, the returned string does not contain any markup. No whitespace normalization is performed, the returned string does not contain the element content whitespaces . Similarly, on setting, no parsing is performed either, the input string is taken as pure textual content.
The string returned is made of the text content of this node depending on its type, as defined below:Node type Content Text
node containing the string this attribute is set to. On getting, no serialization is performed, the returned string does not contain any markup. No whitespace normalization is performed, the returned string does not contain the element content whitespaces . Similarly, on setting, no parsing is performed either, the input string is taken as pure textual content.
The string returned is made of the text content of this node depending on its type, as defined below:Node type Content ELEMENT_NODE, ENTITY_NODE, ENTITY_REFERENCE_NODE, DOCUMENT_FRAGMENT_NODE concatenation of the textContent
attribute value of every child node, excluding COMMENT_NODE and PROCESSING_INSTRUCTION_NODE nodesATTRIBUTE_NODE, TEXT_NODE, CDATA_SECTION_NODE, COMMENT_NODE, PROCESSING_INSTRUCTION_NODE nodeValue
DOCUMENT_NODE, DOCUMENT_TYPE_NODE, NOTATION_NODE null - Specified by:
getTextContent
in interfaceNode
- Overrides:
getTextContent
in classNodeImpl
- Throws:
DOMException
- NO_MODIFICATION_ALLOWED_ERR: Raised when the node is readonly.DOMException
- DOMSTRING_SIZE_ERR: Raised when it would return more characters than fit in aDOMString
variable on the implementation platform.
setTextContent
Description copied from class:NodeImpl
This attribute returns the text content of this node and its descendants. When it is defined to be null, setting it has no effect. When set, any possible children this node may have are removed and replaced by a singleText
node containing the string this attribute is set to. On getting, no serialization is performed, the returned string does not contain any markup. No whitespace normalization is performed, the returned string does not contain the element content whitespaces . Similarly, on setting, no parsing is performed either, the input string is taken as pure textual content.
The string returned is made of the text content of this node depending on its type, as defined below:Node type Content ELEMENT_NODE, ENTITY_NODE, ENTITY_REFERENCE_NODE, DOCUMENT_FRAGMENT_NODE concatenation of the textContent
attribute value of every child node, excluding COMMENT_NODE and PROCESSING_INSTRUCTION_NODE nodesATTRIBUTE_NODE, TEXT_NODE, CDATA_SECTION_NODE, COMMENT_NODE, PROCESSING_INSTRUCTION_NODE nodeValue
DOCUMENT_NODE, DOCUMENT_TYPE_NODE, NOTATION_NODE null - Specified by:
setTextContent
in interfaceNode
- Overrides:
setTextContent
in classNodeImpl
- Throws:
DOMException
- NO_MODIFICATION_ALLOWED_ERR: Raised when the node is readonly.DOMException
- DOMSTRING_SIZE_ERR: Raised when it would return more characters than fit in aDOMString
variable on the implementation platform.
getLength
public int getLength()NodeList method: Count the immediate children of this nodeitem
NodeList method: Return the Nth immediate child of this node, or null if the index is out of bounds.getChildNodesUnoptimized
Create a NodeList to access children that is use by subclass elements that have methods named getLength() or item(int). ChildAndParentNode optimizes getChildNodes() by implementing NodeList itself. However if a subclass Element implements methods with the same name as the NodeList methods, they will override the actually methods in this class.To use this method, the subclass should implement getChildNodes() and have it call this method. The resulting NodeList instance maybe shared and cached in a transient field, but the cached value must be cleared if the node is cloned.
normalize
public void normalize()Override default behavior to call normalize() on this Node's children. It is up to implementors or Node to override normalize() to take action.isEqualNode
DOM Level 3 WD- Experimental. Override inherited behavior from NodeImpl to support deep equal.- Specified by:
isEqualNode
in interfaceNode
- Overrides:
isEqualNode
in classNodeImpl
- Parameters:
arg
- The node to compare equality with.- Returns:
- If the nodes, and possibly subtrees are equal,
true
otherwisefalse
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setReadOnly
public void setReadOnly(boolean readOnly, boolean deep) Override default behavior so that if deep is true, children are also toggled.- Overrides:
setReadOnly
in classNodeImpl
- 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:
synchronizeChildren
protected void synchronizeChildren()Override this method in subclass to hook in efficient internal data structure.
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