Package org.apache.xpath.axes
Class UnionPathIterator
java.lang.Object
org.apache.xpath.Expression
org.apache.xpath.patterns.NodeTest
org.apache.xpath.axes.PredicatedNodeTest
org.apache.xpath.axes.LocPathIterator
org.apache.xpath.axes.UnionPathIterator
- All Implemented Interfaces:
Serializable
,Cloneable
,SourceLocator
,DTMIterator
,PathComponent
,SubContextList
,ExpressionNode
,XPathVisitable
public class UnionPathIterator
extends LocPathIterator
implements Cloneable, DTMIterator, Serializable, PathComponent
This class extends NodeSetDTM, which implements DTMIterator,
and fetches nodes one at a time in document order based on a XPath
UnionExpr.
As each node is iterated via nextNode(), the node is also stored
in the NodeVector, so that previousNode() can easily be done.
- See Also:
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Field Summary
Fields inherited from class org.apache.xpath.axes.LocPathIterator
m_lastFetched
Fields inherited from class org.apache.xpath.patterns.NodeTest
SCORE_NODETEST, SCORE_NONE, SCORE_NSWILD, SCORE_OTHER, SCORE_QNAME, SHOW_BYFUNCTION, SUPPORTS_PRE_STRIPPING, WILD
Fields inherited from interface org.apache.xml.dtm.DTMIterator
FILTER_ACCEPT, FILTER_REJECT, FILTER_SKIP
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Constructor Summary
ConstructorsConstructorDescriptionConstructor to create an instance which you can add location paths to.UnionPathIterator
(Compiler compiler, int opPos) Create a UnionPathIterator object, including creation of location path iterators from the opcode list, and call back into the Compiler to create predicate expressions. -
Method Summary
Modifier and TypeMethodDescriptionvoid
addIterator
(DTMIterator expr) Add an iterator to the union list.void
callVisitors
(ExpressionOwner owner, XPathVisitor visitor) This will traverse the heararchy, calling the visitor for each member.clone()
Get a cloned LocPathIterator that holds the same position as this iterator.static LocPathIterator
createUnionIterator
(Compiler compiler, int opPos) This will return an iterator capable of handling the union of paths given.boolean
deepEquals
(Expression expr) Compare this object with another object and see if they are equal, include the sub heararchy.void
detach()
Detaches the iterator from the set which it iterated over, releasing any computational resources and placing the iterator in the INVALID state.void
fixupVariables
(Vector vars, int globalsSize) This function is used to fixup variables from QNames to stack frame indexes at stylesheet build time.int
Get the analysis bits for this walker, as defined in the WalkerFactory.int
getAxis()
Returns the axis being iterated, if it is known.int
nextNode()
Returns the next node in the set and advances the position of the iterator in the set.void
Initialize the context values for this expression after it is cloned.Methods inherited from class org.apache.xpath.axes.LocPathIterator
allowDetachToRelease, asIterator, asNode, bool, cloneWithReset, execute, executeCharsToContentHandler, getContext, getCurrentContextNode, getCurrentNode, getCurrentPos, getDTM, getDTMManager, getExpandEntityReferences, getFilter, getFoundLast, getIsTopLevel, getLastPos, getLength, getPrefixResolver, getRoot, getWhatToShow, getXPathContext, incrementCurrentPos, isDocOrdered, isFresh, isMutable, isNodesetExpr, item, previousNode, reset, runTo, setCurrentContextNode, setCurrentPos, setEnvironment, setIsTopLevel, setItem, setShouldCacheNodes, size
Methods inherited from class org.apache.xpath.axes.PredicatedNodeTest
acceptNode, callPredicateVisitors, canTraverseOutsideSubtree, getLocPathIterator, getPredicate, getPredicateCount, getPredicateIndex, getProximityPosition, getProximityPosition, initProximityPosition, isReverseAxes, resetProximityPositions, setLocPathIterator, setPredicateCount
Methods inherited from class org.apache.xpath.patterns.NodeTest
debugWhatToShow, execute, execute, getDefaultScore, getLocalName, getNamespace, getNodeTypeTest, getStaticScore, initNodeTest, initNodeTest, setLocalName, setNamespace, setStaticScore, setWhatToShow
Methods inherited from class org.apache.xpath.Expression
asIteratorRaw, assertion, error, execute, exprAddChild, exprGetChild, exprGetNumChildren, exprGetParent, exprSetParent, getColumnNumber, getExpressionOwner, getLineNumber, getPublicId, getSystemId, isStableNumber, num, warn, xstr
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
Methods inherited from interface org.apache.xml.dtm.DTMIterator
allowDetachToRelease, cloneWithReset, getCurrentNode, getCurrentPos, getDTM, getDTMManager, getExpandEntityReferences, getLength, getRoot, getWhatToShow, isDocOrdered, isFresh, isMutable, item, previousNode, reset, runTo, setCurrentPos, setItem, setShouldCacheNodes
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Constructor Details
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UnionPathIterator
public UnionPathIterator()Constructor to create an instance which you can add location paths to. -
UnionPathIterator
Create a UnionPathIterator object, including creation of location path iterators from the opcode list, and call back into the Compiler to create predicate expressions.- Parameters:
compiler
- The Compiler which is creating this expression.opPos
- The position of this iterator in the opcode list from the compiler.- Throws:
TransformerException
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Method Details
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setRoot
Initialize the context values for this expression after it is cloned.- Specified by:
setRoot
in interfaceDTMIterator
- Overrides:
setRoot
in classLocPathIterator
- Parameters:
context
- The XPath runtime context for this transformation.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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addIterator
Add an iterator to the union list.- Parameters:
expr
- non-null reference to a location path iterator.
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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.- Specified by:
detach
in interfaceDTMIterator
- Overrides:
detach
in classLocPathIterator
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createUnionIterator
public static LocPathIterator createUnionIterator(Compiler compiler, int opPos) throws TransformerException This will return an iterator capable of handling the union of paths given.- Parameters:
compiler
- The Compiler which is creating this expression.opPos
- The position of this iterator in the opcode list from the compiler.- Returns:
- Object that is derived from LocPathIterator.
- Throws:
TransformerException
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getAnalysisBits
public int getAnalysisBits()Get the analysis bits for this walker, as defined in the WalkerFactory.- Specified by:
getAnalysisBits
in interfacePathComponent
- Overrides:
getAnalysisBits
in classLocPathIterator
- Returns:
- One of WalkerFactory#BIT_DESCENDANT, etc.
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clone
Get a cloned LocPathIterator that holds the same position as this iterator.- Specified by:
clone
in interfaceDTMIterator
- Overrides:
clone
in classPredicatedNodeTest
- Returns:
- A clone of this iterator that holds the same node position.
- Throws:
CloneNotSupportedException
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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 a DTMIterator is created, the first call to nextNode() returns the first node in the set.- Specified by:
nextNode
in interfaceDTMIterator
- Specified by:
nextNode
in classLocPathIterator
- Returns:
- The next
Node
in the set being iterated over, ornull
if there are no more members in that set.
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fixupVariables
This function is used to fixup variables from QNames to stack frame indexes at stylesheet build time.- Overrides:
fixupVariables
in classPredicatedNodeTest
- Parameters:
vars
- List of QNames that correspond to variables. This list should be searched backwards for the first qualified name that corresponds to the variable reference qname. The position of the QName in the vector from the start of the vector will be its position in the stack frame (but variables above the globalsTop value will need to be offset to the current stack frame).
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getAxis
public int getAxis()Returns the axis being iterated, if it is known.- Specified by:
getAxis
in interfaceDTMIterator
- Overrides:
getAxis
in classLocPathIterator
- Returns:
- Axis.CHILD, etc., or -1 if the axis is not known or is of multiple types.
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callVisitors
Description copied from interface:XPathVisitable
This will traverse the heararchy, calling the visitor for each member. If the called visitor method returns false, the subtree should not be called.- Specified by:
callVisitors
in interfaceXPathVisitable
- Overrides:
callVisitors
in classLocPathIterator
- Parameters:
owner
- The owner of the visitor, where that path may be rewritten if needed.visitor
- The visitor whose appropriate method will be called.- See Also:
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deepEquals
Description copied from class:Expression
Compare this object with another object and see if they are equal, include the sub heararchy.- Overrides:
deepEquals
in classPredicatedNodeTest
- Parameters:
expr
- Another expression object.- Returns:
- true if this objects class and the expr object's class are the same, and the data contained within both objects are considered equal.
- See Also:
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