Package org.htmlunit.xpath.axes
Class WalkingIterator
- java.lang.Object
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- org.htmlunit.xpath.Expression
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- org.htmlunit.xpath.patterns.NodeTest
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- org.htmlunit.xpath.axes.PredicatedNodeTest
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- org.htmlunit.xpath.axes.LocPathIterator
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- org.htmlunit.xpath.axes.WalkingIterator
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- All Implemented Interfaces:
java.lang.Cloneable
,javax.xml.transform.SourceLocator
,PathComponent
,SubContextList
,ExpressionNode
,DTMIterator
,XPathVisitable
- Direct Known Subclasses:
WalkingIteratorSorted
public class WalkingIterator extends LocPathIterator
Location path iterator that uses Walkers.
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Field Summary
Fields Modifier and Type Field Description protected AxesWalker
m_firstWalker
The head of the step walker list.protected AxesWalker
m_lastUsedWalker
The last used step walker in the walker list.-
Fields inherited from class org.htmlunit.xpath.axes.LocPathIterator
m_cdtm, m_clones, m_context, m_currentContextNode, m_execContext, m_lastFetched, m_length, m_pos, m_stackFrame
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Fields inherited from class org.htmlunit.xpath.axes.PredicatedNodeTest
DEBUG_PREDICATECOUNTING, m_foundLast, m_lpi, m_predCount, m_predicateIndex, m_proximityPositions
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Fields inherited from class org.htmlunit.xpath.patterns.NodeTest
m_name, m_whatToShow, SCORE_NODETEST, SCORE_NONE, SCORE_NSWILD, SCORE_OTHER, SCORE_QNAME, SHOW_BYFUNCTION, WILD
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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 WalkingIterator(Compiler compiler, int opPos, int analysis, boolean shouldLoadWalkers)
Create a WalkingIterator iterator, including creation of step walkers from the opcode list, and call back into the Compiler to create predicate expressions.WalkingIterator(PrefixResolver nscontext)
Create a WalkingIterator object.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description void
callVisitors(XPathVisitor visitor)
This will traverse the hierarchy, calling the visitor for each member.java.lang.Object
clone()
boolean
deepEquals(Expression expr)
Compare this object with another object and see if they are equal, include the sub heararchy.void
detach()
Detaches theDTMIterator
from the set which it iterated over, releasing any computational resources and placing the iterator in the INVALID state.int
getAnalysisBits()
Get the analysis bits for this path component, as defined in the WalkerFactory.AxesWalker
getLastUsedWalker()
Get the last used walker.int
nextNode()
Returns the next node in the set and advances the position of the iterator in the set.void
reset()
Reset the iterator to the start.void
setLastUsedWalker(AxesWalker walker)
Set the last used walker.void
setRoot(int context, java.lang.Object environment)
Reset the root node of theDTMIterator
, overriding the value specified when it was created.-
Methods inherited from class org.htmlunit.xpath.axes.LocPathIterator
asIterator, asNode, bool, cloneWithReset, execute, getAxis, getCurrentNode, getCurrentPos, getDTM, getDTMManager, getExpandEntityReferences, getIsTopLevel, getLastPos, getLength, getPrefixResolver, getRoot, getWhatToShow, getXPathContext, incrementCurrentPos, isDocOrdered, isFresh, item, previousNode, returnNextNode, runTo, setCurrentPos, setIsTopLevel, setShouldCacheNodes
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Methods inherited from class org.htmlunit.xpath.axes.PredicatedNodeTest
acceptNode, callPredicateVisitors, canTraverseOutsideSubtree, countProximityPosition, executePredicates, getPredicate, getPredicateCount, getProximityPosition, getProximityPosition, getProximityPosition, initPredicateInfo, initProximityPosition, isReverseAxes, nodeToString, resetProximityPositions, setLocPathIterator, setPredicateCount
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Methods inherited from class org.htmlunit.xpath.patterns.NodeTest
calcScore, execute, execute, getLocalName, getNamespace, getNodeTypeTest, getStaticScore, initNodeTest, initNodeTest, setLocalName, setNamespace, setStaticScore, setWhatToShow
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Methods inherited from class org.htmlunit.xpath.Expression
assertion, error, execute, exprGetParent, exprSetParent, getColumnNumber, getExpressionOwner, getLineNumber, getPublicId, getSystemId, isSameClass, isStableNumber, num
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Field Detail
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m_lastUsedWalker
protected AxesWalker m_lastUsedWalker
The last used step walker in the walker list.
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m_firstWalker
protected AxesWalker m_firstWalker
The head of the step walker list.
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Constructor Detail
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WalkingIterator
WalkingIterator(Compiler compiler, int opPos, int analysis, boolean shouldLoadWalkers) throws javax.xml.transform.TransformerException
Create a WalkingIterator iterator, including creation of step walkers 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.shouldLoadWalkers
- True if walkers should be loaded, or false if this is a derived iterator and it doesn't wish to load child walkers.- Throws:
javax.xml.transform.TransformerException
- if any
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WalkingIterator
public WalkingIterator(PrefixResolver nscontext)
Create a WalkingIterator object.- Parameters:
nscontext
- The namespace context for this iterator, should be OK if null.
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Method Detail
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getAnalysisBits
public int getAnalysisBits()
Get the analysis bits for this path component, 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
public java.lang.Object clone() throws java.lang.CloneNotSupportedException
- Specified by:
clone
in interfaceDTMIterator
- Overrides:
clone
in classPredicatedNodeTest
- Returns:
- A clone of this object.
- 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:
reset
in interfaceDTMIterator
- Overrides:
reset
in classLocPathIterator
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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:
setRoot
in interfaceDTMIterator
- Overrides:
setRoot
in classLocPathIterator
- 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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nextNode
public int nextNode()
Returns the next node in the set and advances the position of the iterator in the set. After aDTMIterator
has 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:
nextNode
in interfaceDTMIterator
- Specified by:
nextNode
in classLocPathIterator
- Returns:
- The next node handle in the set being iterated over, or
DTM.NULL
if there are no more members in that set.
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setLastUsedWalker
public final void setLastUsedWalker(AxesWalker walker)
Set the last used walker.- Parameters:
walker
- The last used walker, or null.
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getLastUsedWalker
public final AxesWalker getLastUsedWalker()
Get the last used walker.- Returns:
- The last used walker, or null.
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detach
public void detach()
Detaches theDTMIterator
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 a runtime exception.- Specified by:
detach
in interfaceDTMIterator
- Overrides:
detach
in classLocPathIterator
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callVisitors
public void callVisitors(XPathVisitor visitor)
This will traverse the hierarchy, 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:
visitor
- The visitor whose appropriate method will be called.
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deepEquals
public boolean deepEquals(Expression expr)
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.
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