Class NodeSet
- All Implemented Interfaces:
Cloneable
,ContextNodeList
,NodeList
,org.w3c.dom.traversal.NodeIterator
The NodeSet class can act as either a NodeVector, NodeList, or NodeIterator. However, in order for it to act as a NodeVector or NodeList, it's required that setShouldCacheNodes(true) be called before the first nextNode() is called, in order that nodes can be added as they are fetched. Derived classes that implement iterators must override runTo(int index), in order that they may run the iteration to the given index.
Note that we directly implement the DOM's NodeIterator interface. We do not emulate all the behavior of the standard NodeIterator. In particular, we do not guarantee to present a "live view" of the document ... but in XSLT, the source document should never be mutated, so this should never be an issue.
Thought: Should NodeSet really implement NodeList and NodeIterator, or should there be specific subclasses of it which do so? The advantage of doing it all here is that all NodeSets will respond to the same calls; the disadvantage is that some of them may return less-than-enlightening results when you do so.
-
Constructor Summary
ConstructorsConstructorDescriptionNodeSet()
Create an empty nodelist.NodeSet
(int blocksize) Create an empty, using the given block size.Create a NodeSet, and copy the members of the given NodeSet into it.Create a NodeSet which contains the given Node.Create a NodeSet, and copy the members of the given nodelist into it.NodeSet
(org.w3c.dom.traversal.NodeIterator ni) Create a NodeSet, and copy the members of the given NodeIterator into it. -
Method Summary
Modifier and TypeMethodDescriptionvoid
addElement
(Node value) Append a Node onto the vector.void
Add a node to the NodeSet.int
addNodeInDocOrder
(Node node, boolean test, XPathContext support) Add the node into a vector of nodes where it should occur in document order.int
addNodeInDocOrder
(Node node, XPathContext support) Add the node into a vector of nodes where it should occur in document order.void
Copy NodeList members into this nodelist, adding in document order.void
Copy NodeList members into this nodelist, adding in document order.void
addNodes
(org.w3c.dom.traversal.NodeIterator iterator) Copy NodeList members into this nodelist, adding in document order.void
addNodesInDocOrder
(NodeList nodelist, XPathContext support) Copy NodeList members into this nodelist, adding in document order.void
addNodesInDocOrder
(org.w3c.dom.traversal.NodeIterator iterator, XPathContext support) Copy NodeList members into this nodelist, adding in document order.void
appendNodes
(NodeSet nodes) Append the nodes to the list.clone()
Get a cloned LocPathIterator.org.w3c.dom.traversal.NodeIterator
Get a cloned Iterator, and reset its state to the beginning of the iteration.boolean
Tell if the table contains the given node.void
detach()
Detaches the iterator from the set which it iterated over, releasing any computational resources and placing the iterator in the INVALID state.elementAt
(int i) Get the nth element.Return the last fetched node.int
Get the current position, which is one less than the next nextNode() call will retrieve.boolean
The value of this flag determines whether the children of entity reference nodes are visible to the iterator.org.w3c.dom.traversal.NodeFilter
The filter object used to screen nodes.int
getLast()
Get the index of the last node in this list.int
The number of nodes in the list.getRoot()
boolean
Get whether or not this is a cached node set.int
This attribute determines which node types are presented via the iterator.int
Searches for the first occurence of the given argument, beginning the search at index, and testing for equality using the equals method.int
Searches for the first occurence of the given argument, beginning the search at index, and testing for equality using the equals method.void
insertElementAt
(Node value, int at) Inserts the specified node in this vector at the specified index.void
insertNode
(Node n, int pos) Insert a node at a given position.boolean
isFresh()
Tells if this NodeSet is "fresh", in other words, if the first nextNode() that is called will return the first node in the set.item
(int index) Returns theindex
th item in the collection.nextNode()
Returns the next node in the set and advances the position of the iterator in the set.final Node
Return the node at the top of the stack without popping the stack.final Node
peepTail()
Return the node at the tail of the vector without popping Special purpose method for TransformerImpl, pushElemTemplateElement.final Node
Return the node one position from the tail without popping.final Node
pop()
Pop a node from the tail of the vector and return the result.final Node
Pop a node from the tail of the vector and return the top of the stack after the pop.final void
popPair()
Pop a pair of nodes from the tail of the stack.final void
popQuick()
Pop a node from the tail of the vector.Returns the previous node in the set and moves the position of the iterator backwards in the set.final void
Append a Node onto the vector.final void
Push a pair of nodes into the stack.void
Inserts the specified node in this vector at the specified index.boolean
Removes the first occurrence of the argument from this vector.void
removeElementAt
(int i) Deletes the component at the specified index.void
removeNode
(Node n) Remove a node.void
reset()
Reset the iterator.void
runTo
(int index) If an index is requested, NodeSet will call this method to run the iterator to the index.void
setCurrentPos
(int i) Set the current position in the node set.void
setElementAt
(Node node, int index) Sets the component at the specified index of this vector to be the specified object.void
setLast
(int last) Set the index of the last node in this list.void
setShouldCacheNodes
(boolean b) If setShouldCacheNodes(true) is called, then nodes will be cached.final void
Set the tail of the stack to the given node.final void
setTailSub1
(Node n) Set the given node one position from the tail.int
size()
Get the length of the list.
-
Constructor Details
-
NodeSet
public NodeSet()Create an empty nodelist. -
NodeSet
public NodeSet(int blocksize) Create an empty, using the given block size.- Parameters:
blocksize
- Size of blocks to allocate
-
NodeSet
Create a NodeSet, and copy the members of the given nodelist into it.- Parameters:
nodelist
- List of Nodes to be made members of the new set.
-
NodeSet
Create a NodeSet, and copy the members of the given NodeSet into it.- Parameters:
nodelist
- Set of Nodes to be made members of the new set.
-
NodeSet
public NodeSet(org.w3c.dom.traversal.NodeIterator ni) Create a NodeSet, and copy the members of the given NodeIterator into it.- Parameters:
ni
- Iterator which yields Nodes to be made members of the new set.
-
NodeSet
Create a NodeSet which contains the given Node.- Parameters:
node
- Single node to be added to the new set.
-
-
Method Details
-
getRoot
- Specified by:
getRoot
in interfaceorg.w3c.dom.traversal.NodeIterator
- Returns:
- The root node of the Iterator, as specified when it was created. For non-Iterator NodeSets, this will be null.
-
cloneWithReset
Get a cloned Iterator, and reset its state to the beginning of the iteration.- Specified by:
cloneWithReset
in interfaceContextNodeList
- Returns:
- a new NodeSet of the same type, having the same state... except that the reset() operation has been called.
- Throws:
CloneNotSupportedException
- if this subclass of NodeSet does not support the clone() operation.
-
reset
public void reset()Reset the iterator. May have no effect on non-iterator Nodesets.- Specified by:
reset
in interfaceContextNodeList
-
getWhatToShow
public int getWhatToShow()This attribute determines which node types are presented via the iterator. The available set of constants is defined in theNodeFilter
interface. For NodeSets, the mask has been hardcoded to show all nodes except EntityReference nodes, which have no equivalent in the XPath data model.- Specified by:
getWhatToShow
in interfaceorg.w3c.dom.traversal.NodeIterator
- Returns:
- integer used as a bit-array, containing flags defined in
the DOM's NodeFilter class. The value will be
SHOW_ALL & ~SHOW_ENTITY_REFERENCE
, meaning that only entity references are suppressed.
-
getFilter
public org.w3c.dom.traversal.NodeFilter getFilter()The filter object used to screen nodes. Filters are applied to further reduce (and restructure) the NodeIterator's view of the document. In our case, we will be using hardcoded filters built into our iterators... but getFilter() is part of the DOM's NodeIterator interface, so we have to support it.- Specified by:
getFilter
in interfaceorg.w3c.dom.traversal.NodeIterator
- Returns:
- null, which is slightly misleading. True, there is no user-written filter object, but in fact we are doing some very sophisticated custom filtering. A DOM purist might suggest returning a placeholder object just to indicate that this is not going to return all nodes selected by whatToShow.
-
getExpandEntityReferences
public boolean getExpandEntityReferences()The value of this flag determines whether the children of entity reference nodes are visible to the iterator. If false, they will be skipped over.
To produce a view of the document that has entity references expanded and does not expose the entity reference node itself, use the whatToShow flags to hide the entity reference node and set expandEntityReferences to true when creating the iterator. To produce a view of the document that has entity reference nodes but no entity expansion, use the whatToShow flags to show the entity reference node and set expandEntityReferences to false.- Specified by:
getExpandEntityReferences
in interfaceorg.w3c.dom.traversal.NodeIterator
- Returns:
- true for all iterators based on NodeSet, meaning that the contents of EntityRefrence nodes may be returned (though whatToShow says that the EntityReferences themselves are not shown.)
-
nextNode
Returns the next node in the set and advances the position of the iterator in the set. After a NodeIterator is created, the first call to nextNode() returns the first node in the set.- Specified by:
nextNode
in interfaceorg.w3c.dom.traversal.NodeIterator
- Returns:
- The next
Node
in the set being iterated over, ornull
if there are no more members in that set. - Throws:
DOMException
- INVALID_STATE_ERR: Raised if this method is called after thedetach
method was invoked.
-
previousNode
Returns the previous node in the set and moves the position of the iterator backwards in the set.- Specified by:
previousNode
in interfaceorg.w3c.dom.traversal.NodeIterator
- Returns:
- The previous
Node
in the set being iterated over, ornull
if there are no more members in that set. - Throws:
DOMException
- INVALID_STATE_ERR: Raised if this method is called after thedetach
method was invoked.RuntimeException
- thrown if this NodeSet is not of a cached type, and hence doesn't know what the previous node was.
-
detach
public void detach()Detaches the iterator from the set which it iterated over, releasing any computational resources and placing the iterator in the INVALID state. Afterdetach
has been invoked, calls tonextNode
orpreviousNode
will raise the exception INVALID_STATE_ERR.This operation is a no-op in NodeSet, and will not cause INVALID_STATE_ERR to be raised by later operations.
- Specified by:
detach
in interfaceorg.w3c.dom.traversal.NodeIterator
-
isFresh
public boolean isFresh()Tells if this NodeSet is "fresh", in other words, if the first nextNode() that is called will return the first node in the set.- Specified by:
isFresh
in interfaceContextNodeList
- Returns:
- true if nextNode() would return the first node in the set, false if it would return a later one.
-
runTo
public void runTo(int index) If an index is requested, NodeSet will call this method to run the iterator to the index. By default this sets m_next to the index. If the index argument is -1, this signals that the iterator should be run to the end.- Specified by:
runTo
in interfaceContextNodeList
- Parameters:
index
- Position to advance (or retreat) to, with 0 requesting the reset ("fresh") position and -1 (or indeed any out-of-bounds value) requesting the final position.- Throws:
RuntimeException
- thrown if this NodeSet is not one of the types which supports indexing/counting.
-
item
Returns theindex
th item in the collection. Ifindex
is greater than or equal to the number of nodes in the list, this returnsnull
. TODO: What happens if index is out of range? -
getLength
public int getLength()The number of nodes in the list. The range of valid child node indices is 0 tolength-1
inclusive. Note that this operation requires finding all the matching nodes, which may defeat attempts to defer that work. -
addNode
Add a node to the NodeSet. Not all types of NodeSets support this operation- Parameters:
n
- Node to be added- Throws:
RuntimeException
- thrown if this NodeSet is not of a mutable type.
-
insertNode
Insert a node at a given position.- Parameters:
n
- Node to be addedpos
- Offset at which the node is to be inserted, with 0 being the first position.- Throws:
RuntimeException
- thrown if this NodeSet is not of a mutable type.
-
removeNode
Remove a node.- Parameters:
n
- Node to be added- Throws:
RuntimeException
- thrown if this NodeSet is not of a mutable type.
-
addNodes
Copy NodeList members into this nodelist, adding in document order. If a node is null, don't add it.- Parameters:
nodelist
- List of nodes which should now be referenced by this NodeSet.- Throws:
RuntimeException
- thrown if this NodeSet is not of a mutable type.
-
addNodes
Copy NodeList members into this nodelist, adding in document order. Only genuine node references will be copied; nulls appearing in the source NodeSet will not be added to this one.
In case you're wondering why this function is needed: NodeSet implements both NodeIterator and NodeList. If this method isn't provided, Java can't decide which of those to use when addNodes() is invoked. Providing the more-explicit match avoids that ambiguity.)
- Parameters:
ns
- NodeSet whose members should be merged into this NodeSet.- Throws:
RuntimeException
- thrown if this NodeSet is not of a mutable type.
-
addNodes
public void addNodes(org.w3c.dom.traversal.NodeIterator iterator) Copy NodeList members into this nodelist, adding in document order. Null references are not added.- Parameters:
iterator
- NodeIterator which yields the nodes to be added.- Throws:
RuntimeException
- thrown if this NodeSet is not of a mutable type.
-
addNodesInDocOrder
Copy NodeList members into this nodelist, adding in document order. If a node is null, don't add it.- Parameters:
nodelist
- List of nodes to be addedsupport
- The XPath runtime context.- Throws:
RuntimeException
- thrown if this NodeSet is not of a mutable type.
-
addNodesInDocOrder
Copy NodeList members into this nodelist, adding in document order. If a node is null, don't add it.- Parameters:
iterator
- NodeIterator which yields the nodes to be added.support
- The XPath runtime context.- Throws:
RuntimeException
- thrown if this NodeSet is not of a mutable type.
-
addNodeInDocOrder
Add the node into a vector of nodes where it should occur in document order.- Parameters:
node
- The node to be added.test
- true if we should test for doc ordersupport
- The XPath runtime context.- Returns:
- insertIndex.
- Throws:
RuntimeException
- thrown if this NodeSet is not of a mutable type.
-
addNodeInDocOrder
Add the node into a vector of nodes where it should occur in document order.- Parameters:
node
- The node to be added.support
- The XPath runtime context.- Returns:
- The index where it was inserted.
- Throws:
RuntimeException
- thrown if this NodeSet is not of a mutable type.
-
getCurrentPos
public int getCurrentPos()Get the current position, which is one less than the next nextNode() call will retrieve. i.e. if you call getCurrentPos() and the return is 0, the next fetch will take place at index 1.- Specified by:
getCurrentPos
in interfaceContextNodeList
- Returns:
- The the current position index.
-
setCurrentPos
public void setCurrentPos(int i) Set the current position in the node set.- Specified by:
setCurrentPos
in interfaceContextNodeList
- Parameters:
i
- Must be a valid index.- Throws:
RuntimeException
- thrown if this NodeSet is not of a cached type, and thus doesn't permit indexed access.
-
getCurrentNode
Return the last fetched node. Needed to support the UnionPathIterator.- Specified by:
getCurrentNode
in interfaceContextNodeList
- Returns:
- the last fetched node.
- Throws:
RuntimeException
- thrown if this NodeSet is not of a cached type, and thus doesn't permit indexed access.
-
getShouldCacheNodes
public boolean getShouldCacheNodes()Get whether or not this is a cached node set.- Returns:
- True if this list is cached.
-
setShouldCacheNodes
public void setShouldCacheNodes(boolean b) If setShouldCacheNodes(true) is called, then nodes will be cached. They are not cached by default. This switch must be set before the first call to nextNode is made, to ensure that all nodes are cached.- Specified by:
setShouldCacheNodes
in interfaceContextNodeList
- Parameters:
b
- true if this node set should be cached.- Throws:
RuntimeException
- thrown if an attempt is made to request caching after we've already begun stepping through the nodes in this set.
-
getLast
public int getLast()Description copied from interface:ContextNodeList
Get the index of the last node in this list.- Specified by:
getLast
in interfaceContextNodeList
- Returns:
- the index of the last node in this list.
-
setLast
public void setLast(int last) Description copied from interface:ContextNodeList
Set the index of the last node in this list.- Specified by:
setLast
in interfaceContextNodeList
- Parameters:
last
- the index of the last node in this list.
-
clone
Get a cloned LocPathIterator.- Specified by:
clone
in interfaceContextNodeList
- Returns:
- A clone of this
- Throws:
CloneNotSupportedException
-
size
public int size()Get the length of the list.- Specified by:
size
in interfaceContextNodeList
- Returns:
- Number of nodes in this NodeVector
-
addElement
Append a Node onto the vector.- Parameters:
value
- Node to add to the vector
-
push
Append a Node onto the vector.- Parameters:
value
- Node to add to the vector
-
pop
Pop a node from the tail of the vector and return the result.- Returns:
- the node at the tail of the vector
-
popAndTop
Pop a node from the tail of the vector and return the top of the stack after the pop.- Returns:
- The top of the stack after it's been popped
-
popQuick
public final void popQuick()Pop a node from the tail of the vector. -
peepOrNull
Return the node at the top of the stack without popping the stack. Special purpose method for TransformerImpl, pushElemTemplateElement. Performance critical.- Returns:
- Node at the top of the stack or null if stack is empty.
-
pushPair
Push a pair of nodes into the stack. Special purpose method for TransformerImpl, pushElemTemplateElement. Performance critical.- Parameters:
v1
- First node to add to vectorv2
- Second node to add to vector
-
popPair
public final void popPair()Pop a pair of nodes from the tail of the stack. Special purpose method for TransformerImpl, pushElemTemplateElement. Performance critical. -
setTail
Set the tail of the stack to the given node. Special purpose method for TransformerImpl, pushElemTemplateElement. Performance critical.- Parameters:
n
- Node to set at the tail of vector
-
setTailSub1
Set the given node one position from the tail. Special purpose method for TransformerImpl, pushElemTemplateElement. Performance critical.- Parameters:
n
- Node to set
-
peepTail
Return the node at the tail of the vector without popping Special purpose method for TransformerImpl, pushElemTemplateElement. Performance critical.- Returns:
- Node at the tail of the vector
-
peepTailSub1
Return the node one position from the tail without popping. Special purpose method for TransformerImpl, pushElemTemplateElement. Performance critical.- Returns:
- Node one away from the tail
-
insertElementAt
Inserts the specified node in this vector at the specified index. Each component in this vector with an index greater or equal to the specified index is shifted upward to have an index one greater than the value it had previously.- Parameters:
value
- Node to insertat
- Position where to insert
-
appendNodes
Append the nodes to the list.- Parameters:
nodes
- NodeVector to append to this list
-
removeAllElements
public void removeAllElements()Inserts the specified node in this vector at the specified index. Each component in this vector with an index greater or equal to the specified index is shifted upward to have an index one greater than the value it had previously. -
removeElement
Removes the first occurrence of the argument from this vector. If the object is found in this vector, each component in the vector with an index greater or equal to the object's index is shifted downward to have an index one smaller than the value it had previously.- Parameters:
s
- Node to remove from the list- Returns:
- True if the node was successfully removed
-
removeElementAt
public void removeElementAt(int i) Deletes the component at the specified index. Each component in this vector with an index greater or equal to the specified index is shifted downward to have an index one smaller than the value it had previously.- Parameters:
i
- Index of node to remove
-
setElementAt
Sets the component at the specified index of this vector to be the specified object. The previous component at that position is discarded. The index must be a value greater than or equal to 0 and less than the current size of the vector.- Parameters:
node
- Node to setindex
- Index of where to set the node
-
elementAt
Get the nth element.- Parameters:
i
- Index of node to get- Returns:
- Node at specified index
-
contains
Tell if the table contains the given node.- Parameters:
s
- Node to look for- Returns:
- True if the given node was found.
-
indexOf
Searches for the first occurence of the given argument, beginning the search at index, and testing for equality using the equals method.- Parameters:
elem
- Node to look forindex
- Index of where to start the search- Returns:
- the index of the first occurrence of the object argument in this vector at position index or later in the vector; returns -1 if the object is not found.
-
indexOf
Searches for the first occurence of the given argument, beginning the search at index, and testing for equality using the equals method.- Parameters:
elem
- Node to look for- Returns:
- the index of the first occurrence of the object argument in this vector at position index or later in the vector; returns -1 if the object is not found.
-