Class NodeSetDTM
- java.lang.Object
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- org.htmlunit.xpath.xml.utils.NodeVector
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- org.htmlunit.xpath.NodeSetDTM
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- All Implemented Interfaces:
java.lang.Cloneable,DTMIterator
public class NodeSetDTM extends NodeVector implements DTMIterator, java.lang.Cloneable
The NodeSetDTM 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 NodeSetDTM 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 NodeSetDTMs will respond to the same calls; the disadvantage is that some of them may return less-than-enlightening results when you do so.
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Field Summary
Fields Modifier and Type Field Description protected booleanm_cacheNodesTrue if this list is cached.(package private) DTMManagerm_managerprotected intm_nextIf this node is being used as an iterator, the next index that nextNode() will return.protected intm_rootThe root of the iteration, if available.-
Fields inherited from class org.htmlunit.xpath.xml.utils.NodeVector
m_firstFree
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Fields inherited from interface org.htmlunit.xpath.xml.dtm.DTMIterator
FILTER_ACCEPT, FILTER_SKIP
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Constructor Summary
Constructors Constructor Description NodeSetDTM(DTMIterator ni)Create a NodeSetDTM, and copy the members of the given DTMIterator into it.NodeSetDTM(DTMManager dtmManager)Create an empty nodelist.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description voidaddNode(int n)Add a node to the NodeSetDTM.voidaddNodeInDocOrder(int node, boolean test, XPathContext support)Add the node into a vector of nodes where it should occur in document order.voidaddNodeInDocOrder(int node, XPathContext support)Add the node into a vector of nodes where it should occur in document order.voidaddNodes(DTMIterator iterator)Copy NodeList members into this nodelist, adding in document order.java.lang.Objectclone()DTMIteratorcloneWithReset()Get a cloned Iterator that is reset to the start of the iteration.booleancontains(int s)Tell if the table contains the given node.voiddetach()Detaches theDTMIteratorfrom the set which it iterated over, releasing any computational resources and placing the iterator in the INVALID state.intelementAt(int i)Get the nth element.intgetAxis()Returns the axis being iterated, if it is known.intgetCurrentNode()Get the current node in the iterator.intgetCurrentPos()Get the current position within the cached list, which is one less than the next nextNode() call will retrieve.DTMgetDTM(int nodeHandle)Get an instance of a DTM that "owns" a node handle.DTMManagergetDTMManager()Get an instance of the DTMManager.booleangetExpandEntityReferences()The value of this flag determines whether the children of entity reference nodes are visible to the iterator.intgetLength()The number of nodes in the list.intgetRoot()The root node of theDTMIterator, as specified when it was created.intgetWhatToShow()This attribute determines which node types are presented via the iterator.intindexOf(int elem)Searches for the first occurence of the given argument, beginning the search at index, and testing for equality using the equals method.intindexOf(int elem, int index)Searches for the first occurence of the given argument, beginning the search at index, and testing for equality using the equals method.booleanisDocOrdered()Returns true if all the nodes in the iteration well be returned in document order.booleanisFresh()Tells if this NodeSetDTM is "fresh", in other words, if the first nextNode() that is called will return the first node in the set.intitem(int index)Returns thenode handleof an item in the collection.intnextNode()Returns the next node in the set and advances the position of the iterator in the set.intpreviousNode()Returns the previous node in the set and moves the position of theDTMIteratorbackwards in the set.voidreset()Reset the iterator to the start.voidrunTo(int index)If an index is requested, NodeSetDTM will call this method to run the iterator to the index.voidsetCurrentPos(int i)Set the current position in the node set.voidsetRoot(int context, java.lang.Object environment)Reset the root node of theDTMIterator, overriding the value specified when it was created.voidsetShouldCacheNodes(boolean b)If setShouldCacheNodes(true) is called, then nodes will be cached, enabling random access, and giving the ability to do sorts and the like.-
Methods inherited from class org.htmlunit.xpath.xml.utils.NodeVector
addElement, insertElementAt, size
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Field Detail
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m_manager
final DTMManager m_manager
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m_next
protected transient int m_next
If this node is being used as an iterator, the next index that nextNode() will return.
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m_cacheNodes
protected transient boolean m_cacheNodes
True if this list is cached.
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m_root
protected int m_root
The root of the iteration, if available.
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Constructor Detail
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NodeSetDTM
public NodeSetDTM(DTMManager dtmManager)
Create an empty nodelist.
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NodeSetDTM
public NodeSetDTM(DTMIterator ni)
Create a NodeSetDTM, and copy the members of the given DTMIterator into it.- Parameters:
ni- Iterator which yields Nodes to be made members of the new set.
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Method Detail
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getRoot
public int getRoot()
The root node of theDTMIterator, as specified when it was created. Note the root node is not the root node of the document tree, but the context node from where the iteration begins and ends.- Specified by:
getRootin interfaceDTMIterator- Returns:
- nodeHandle int Handle of the context node.
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setRoot
public void setRoot(int context, java.lang.Object environment)Reset the root node of theDTMIterator, overriding the value specified when it was created. Note the root node is not the root node of the document tree, but the context node from where the iteration begins.- Specified by:
setRootin interfaceDTMIterator- Parameters:
context- int Handle of the context node.environment- The environment object. The environment in which this iterator operates, which should provide:- a node (the context node... same value as "root" defined below)
- a pair of non-zero positive integers (the context position and the context size)
- a set of variable bindings
- a function library
- the set of namespace declarations in scope for the expression.
At this time the exact implementation of this environment is application dependent. Probably a proper interface will be created fairly soon.
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clone
public java.lang.Object clone() throws java.lang.CloneNotSupportedException- Specified by:
clonein interfaceDTMIterator- Overrides:
clonein classNodeVector- Returns:
- A clone of this object.
- Throws:
java.lang.CloneNotSupportedException- if any
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cloneWithReset
public DTMIterator cloneWithReset() throws java.lang.CloneNotSupportedException
Get a cloned Iterator that is reset to the start of the iteration.- Specified by:
cloneWithResetin interfaceDTMIterator- Returns:
- A clone of this iteration that has been reset.
- Throws:
java.lang.CloneNotSupportedException- if any
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reset
public void reset()
Reset the iterator to the start. After resetting, the next node returned will be the root node -- or, if that's filtered out, the first node within the root's subtree which is _not_ skipped by the filters.- Specified by:
resetin interfaceDTMIterator
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getWhatToShow
public int getWhatToShow()
This attribute determines which node types are presented via the iterator. The available set of constants is defined above. Nodes not accepted bywhatToShowwill be skipped, but their children may still be considered.- Specified by:
getWhatToShowin interfaceDTMIterator- Returns:
- one of the SHOW_XXX constants, or several ORed together.
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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 and their descendants will be rejected. Note that this rejection takes precedence overwhatToShowand the filter.To produce a view of the document that has entity references expanded and does not expose the entity reference node itself, use the
whatToShowflags to hide the entity reference node and setexpandEntityReferencesto true when creating the iterator. To produce a view of the document that has entity reference nodes but no entity expansion, use thewhatToShowflags to show the entity reference node and setexpandEntityReferencesto false.NOTE: In Xalan's use of DTM we will generally have fully expanded entity references when the document tree was built, and thus this flag will have no effect.
- Specified by:
getExpandEntityReferencesin interfaceDTMIterator- Returns:
- true if entity references will be expanded.
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getDTM
public DTM getDTM(int nodeHandle)
Get an instance of a DTM that "owns" a node handle. Since a node iterator may be passed without a DTMManager, this allows the caller to easily get the DTM using just the iterator.- Specified by:
getDTMin interfaceDTMIterator- Parameters:
nodeHandle- the nodeHandle.- Returns:
- a non-null DTM reference.
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getDTMManager
public DTMManager getDTMManager()
Get an instance of the DTMManager. Since a node iterator may be passed without a DTMManager, this allows the caller to easily get the DTMManager using just the iterator.- Specified by:
getDTMManagerin interfaceDTMIterator- Returns:
- a non-null DTMManager reference.
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nextNode
public int nextNode()
Returns the next node in the set and advances the position of the iterator in the set. After aDTMIteratorhas setRoot called, the first call tonextNode()returns that root or (if it is rejected by the filters) the first node within its subtree which is not filtered out.- Specified by:
nextNodein interfaceDTMIterator- Returns:
- The next node handle in the set being iterated over, or
DTM.NULLif there are no more members in that set.
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previousNode
public int previousNode()
Returns the previous node in the set and moves the position of theDTMIteratorbackwards in the set.- Specified by:
previousNodein interfaceDTMIterator- Returns:
- The previous node handle in the set being iterated over, or
DTM.NULLif there are no more members in that set.
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detach
public void detach()
Detaches theDTMIteratorfrom the set which it iterated over, releasing any computational resources and placing the iterator in the INVALID state. Afterdetachhas been invoked, calls tonextNodeorpreviousNodewill raise a runtime exception.- Specified by:
detachin interfaceDTMIterator
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isFresh
public boolean isFresh()
Tells if this NodeSetDTM is "fresh", in other words, if the first nextNode() that is called will return the first node in the set.- Specified by:
isFreshin interfaceDTMIterator- Returns:
- true if the iteration of this list has not yet begun.
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runTo
public void runTo(int index)
If an index is requested, NodeSetDTM 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 and completely fill the cache.- Specified by:
runToin interfaceDTMIterator- Parameters:
index- The index to run to, or -1 if the iterator should be run to the end.
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item
public int item(int index)
Returns thenode handleof an item in the collection. Ifindexis greater than or equal to the number of nodes in the list, this returnsnull.- Specified by:
itemin interfaceDTMIterator- Parameters:
index- of the item.- Returns:
- The node handle at the
indexth position in theDTMIterator, or-1if that is not a valid index.
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getLength
public int getLength()
The number of nodes in the list. The range of valid child node indices is 0 tolength-1inclusive. Note that this requires running the iterator to completion, and presumably filling the cache.- Specified by:
getLengthin interfaceDTMIterator- Returns:
- The number of nodes in the list.
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addNode
public void addNode(int n)
Add a node to the NodeSetDTM. Not all types of NodeSetDTMs support this operation- Parameters:
n- Node to be added- Throws:
java.lang.RuntimeException- thrown if this NodeSetDTM is not of a mutable type.
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addNodes
public void addNodes(DTMIterator iterator)
Copy NodeList members into this nodelist, adding in document order. Null references are not added.- Parameters:
iterator- DTMIterator which yields the nodes to be added.- Throws:
java.lang.RuntimeException- thrown if this NodeSetDTM is not of a mutable type.
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addNodeInDocOrder
public void addNodeInDocOrder(int node, boolean test, XPathContext support)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.- Throws:
java.lang.RuntimeException- thrown if this NodeSetDTM is not of a mutable type.
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addNodeInDocOrder
public void addNodeInDocOrder(int node, XPathContext support)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.- Throws:
java.lang.RuntimeException- thrown if this NodeSetDTM is not of a mutable type.
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elementAt
public int elementAt(int i)
Get the nth element.- Overrides:
elementAtin classNodeVector- Parameters:
i- Index of node to get- Returns:
- Node at specified index
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contains
public boolean contains(int s)
Tell if the table contains the given node.- Overrides:
containsin classNodeVector- Parameters:
s- Node to look for- Returns:
- True if the given node was found.
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indexOf
public int indexOf(int elem, int index)Searches for the first occurence of the given argument, beginning the search at index, and testing for equality using the equals method.- Overrides:
indexOfin classNodeVector- 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.
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indexOf
public int indexOf(int elem)
Searches for the first occurence of the given argument, beginning the search at index, and testing for equality using the equals method.- Overrides:
indexOfin classNodeVector- 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.
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getCurrentPos
public int getCurrentPos()
Get the current position within the cached list, 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:
getCurrentPosin interfaceDTMIterator- Returns:
- The position of the iteration.
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setCurrentPos
public void setCurrentPos(int i)
Set the current position in the node set.- Specified by:
setCurrentPosin interfaceDTMIterator- Parameters:
i- Must be a valid index.
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getCurrentNode
public int getCurrentNode()
Get the current node in the iterator. Note that this differs from the DOM's NodeIterator, where the current position lies between two nodes (as part of the maintain-relative-position semantic).- Specified by:
getCurrentNodein interfaceDTMIterator- Returns:
- The current node handle, or -1.
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setShouldCacheNodes
public void setShouldCacheNodes(boolean b)
If setShouldCacheNodes(true) is called, then nodes will be cached, enabling random access, and giving the ability to do sorts and the like. They are not cached by default.%REVIEW% Shouldn't the other random-access methods throw an exception if they're called on a DTMIterator with this flag set false?
- Specified by:
setShouldCacheNodesin interfaceDTMIterator- Parameters:
b- true if the nodes should be cached.
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isDocOrdered
public boolean isDocOrdered()
Returns true if all the nodes in the iteration well be returned in document order.- Specified by:
isDocOrderedin interfaceDTMIterator- Returns:
- true if all the nodes in the iteration well be returned in document order.
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getAxis
public int getAxis()
Returns the axis being iterated, if it is known.- Specified by:
getAxisin interfaceDTMIterator- Returns:
- Axis.CHILD, etc., or -1 if the axis is not known or is of multiple types.
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