org.apache.xpath

Class XPathContext

public class XPathContext extends DTMManager

Default class for the runtime execution context for XPath.

This class extends DTMManager but does not directly implement it.

UNKNOWN: advanced

Nested Class Summary
classXPathContext.XPathExpressionContext
Field Summary
XMLReaderm_primaryReader
The reader of the primary source tree.
static intRECURSIONLIMIT
The ammount to use for stacks that record information during the recursive execution.
Constructor Summary
XPathContext()
Create an XPathContext instance.
XPathContext(Object owner)
Create an XPathContext instance.
Method Summary
DTMcreateDocumentFragment()
Creates an empty DocumentFragment object.
DTMIteratorcreateDTMIterator(Object xpathCompiler, int pos)
Create a new DTMIterator based on an XPath UnionExpr.
DTMIteratorcreateDTMIterator(String xpathString, PrefixResolver presolver)
Create a new DTMIterator based on an XPath UnionExpr.
DTMIteratorcreateDTMIterator(int whatToShow, DTMFilter filter, boolean entityReferenceExpansion)
Create a new DTMIterator based only on a whatToShow and a DTMFilter.
DTMIteratorcreateDTMIterator(int node)
Create a new DTMIterator that holds exactly one node.
StackgetAxesIteratorStackStacks()
intgetContextNode()
Get the current context node.
DTMIteratorgetContextNodeList()
Get the current context node list.
StackgetContextNodeListsStack()
DTMIteratorgetContextNodes()
Get the current context node list.
intgetCurrentExpressionNode()
Get the current node that is the expression's context (i.e. for current() support).
IntStackgetCurrentExpressionNodeStack()
intgetCurrentNode()
Get the current context node.
SubContextListgetCurrentNodeList()
Get the current node list as defined by the XSLT spec.
IntStackgetCurrentNodeStack()
DTMgetDTM(Source source, boolean unique, DTMWSFilter wsfilter, boolean incremental, boolean doIndexing)
Get an instance of a DTM, loaded with the content from the specified source.
DTMgetDTM(int nodeHandle)
Get an instance of a DTM that "owns" a node handle.
intgetDTMHandleFromNode(Node node)
Given a W3C DOM node, try and return a DTM handle.
intgetDTMIdentity(DTM dtm)
%TBD% Doc
DTMManagergetDTMManager()
Return the DTMManager object.
DTMXRTreeFraggetDTMXRTreeFrag(int dtmIdentity)
Gets DTMXRTreeFrag object if one has already been created.
ErrorListenergetErrorListener()
Get the ErrorListener where errors and warnings are to be reported.
ExpressionContextgetExpressionContext()
The the expression context for extensions for this context.
DTMgetGlobalRTFDTM()
Get a DTM to be used as a container for a global Result Tree Fragment.
intgetIteratorRoot()
Get the current location path iterator root.
PrefixResolvergetNamespaceContext()
Get the current namespace context for the xpath.
ObjectgetOwnerObject()
Get the "owner" context of this context, which should be, in the case of XSLT, the Transformer object.
intgetPredicatePos()
intgetPredicateRoot()
Get the current predicate root.
XMLReadergetPrimaryReader()
Get primary XMLReader associated with this execution context.
DTMgetRTFDTM()
Get a DTM to be used as a container for a dynamic Result Tree Fragment.
SourceLocatorgetSAXLocator()
Get the current locater in the stylesheet.
SourceTreeManagergetSourceTreeManager()
Get the SourceTreeManager associated with this execution context.
SubContextListgetSubContextList()
Get the current axes iterator, or return null if none.
URIResolvergetURIResolver()
Get the URIResolver associated with this execution context.
VariableStackgetVarStack()
Get the variable stack, which is in charge of variables and parameters.
booleanisSecureProcessing()
Return the state of the secure processing feature
voidpopContextNodeList()
Pop the current context node list.
voidpopCurrentExpressionNode()
Pop the current node that is the expression's context (i.e. for current() support).
voidpopCurrentNode()
Pop the current context node.
voidpopCurrentNodeAndExpression()
Set the current context node.
voidpopExpressionState()
Pop the current context node, expression node, and prefix resolver.
voidpopIteratorRoot()
Pop the current location path iterator root.
voidpopNamespaceContext()
Pop the current namespace context for the xpath.
voidpopPredicatePos()
voidpopPredicateRoot()
Pop the current predicate root.
voidpopRTFContext()
Pop the RTFDTM's context mark.
voidpopSAXLocator()
Pop the current locater.
voidpopSubContextList()
Pop the last pushed axes iterator.
voidpushContextNodeList(DTMIterator nl)
Set the current context node list.
voidpushCurrentExpressionNode(int n)
Set the current node that is the expression's context (i.e. for current() support).
voidpushCurrentNode(int n)
Set the current context node.
voidpushCurrentNodeAndExpression(int cn, int en)
Set the current context node and expression node.
voidpushExpressionState(int cn, int en, PrefixResolver nc)
Push the current context node, expression node, and prefix resolver.
voidpushIteratorRoot(int n)
Set the current location path iterator root.
voidpushNamespaceContext(PrefixResolver pr)
Push a current namespace context for the xpath.
voidpushNamespaceContextNull()
Just increment the namespace contest stack, so that setNamespaceContext can be used on the slot.
voidpushPredicatePos(int n)
voidpushPredicateRoot(int n)
Set the current predicate root.
voidpushRTFContext()
Push the RTFDTM's context mark, to allows discarding RTFs added after this point.
voidpushSAXLocator(SourceLocator location)
Set the current locater in the stylesheet.
voidpushSAXLocatorNull()
Push a slot on the locations stack so that setSAXLocator can be repeatedly called.
voidpushSubContextList(SubContextList iter)
Push a TreeWalker on the stack.
booleanrelease(DTM dtm, boolean shouldHardDelete)
Release a DTM either to a lru pool, or completely remove reference.
voidreset()
Reset for new run.
voidsetAxesIteratorStackStacks(Stack s)
voidsetContextNodeListsStack(Stack s)
voidsetCurrentExpressionNodeStack(IntStack nv)
voidsetCurrentNodeStack(IntStack nv)
voidsetErrorListener(ErrorListener listener)
Set the ErrorListener where errors and warnings are to be reported.
voidsetNamespaceContext(PrefixResolver pr)
Get the current namespace context for the xpath.
voidsetPrimaryReader(XMLReader reader)
Set primary XMLReader associated with this execution context.
voidsetSAXLocator(SourceLocator location)
Set the current locater in the stylesheet.
voidsetSecureProcessing(boolean flag)
Set the state of the secure processing feature
voidsetSourceTreeManager(SourceTreeManager mgr)
Set the SourceTreeManager associated with this execution context.
voidsetURIResolver(URIResolver resolver)
Set the URIResolver associated with this execution context.
voidsetVarStack(VariableStack varStack)
Get the variable stack, which is in charge of variables and parameters.

Field Detail

m_primaryReader

public XMLReader m_primaryReader
The reader of the primary source tree.

RECURSIONLIMIT

public static final int RECURSIONLIMIT
The ammount to use for stacks that record information during the recursive execution.

Constructor Detail

XPathContext

public XPathContext()
Create an XPathContext instance.

XPathContext

public XPathContext(Object owner)
Create an XPathContext instance.

Parameters: owner Value that can be retrieved via the getOwnerObject() method.

See Also: XPathContext

Method Detail

createDocumentFragment

public DTM createDocumentFragment()
Creates an empty DocumentFragment object.

Returns: A new DocumentFragment handle.

createDTMIterator

public DTMIterator createDTMIterator(Object xpathCompiler, int pos)
Create a new DTMIterator based on an XPath UnionExpr.

Parameters: xpathCompiler ??? Somehow we need to pass in a subpart of the expression. I hate to do this with strings, since the larger expression has already been parsed. pos The position in the expression.

Returns: The newly created DTMIterator.

createDTMIterator

public DTMIterator createDTMIterator(String xpathString, PrefixResolver presolver)
Create a new DTMIterator based on an XPath UnionExpr.

Parameters: xpathString Must be a valid string expressing a UnionExpr. presolver An object that can resolve prefixes to namespace URLs.

Returns: The newly created DTMIterator.

createDTMIterator

public DTMIterator createDTMIterator(int whatToShow, DTMFilter filter, boolean entityReferenceExpansion)
Create a new DTMIterator based only on a whatToShow and a DTMFilter. The traversal semantics are defined as the descendant access.

Parameters: whatToShow This flag specifies which node types may appear in the logical view of the tree presented by the iterator. See the description of NodeFilter for the set of possible SHOW_ values.These flags can be combined using OR. filter The NodeFilter to be used with this TreeWalker, or null to indicate no filter. entityReferenceExpansion The value of this flag determines whether entity reference nodes are expanded.

Returns: The newly created NodeIterator.

createDTMIterator

public DTMIterator createDTMIterator(int node)
Create a new DTMIterator that holds exactly one node.

Parameters: node The node handle that the DTMIterator will iterate to.

Returns: The newly created DTMIterator.

getAxesIteratorStackStacks

public Stack getAxesIteratorStackStacks()

getContextNode

public final int getContextNode()
Get the current context node.

Returns: The current context node.

getContextNodeList

public final DTMIterator getContextNodeList()
Get the current context node list.

Returns: the current node list, also refered to here as a context node list.

getContextNodeListsStack

public Stack getContextNodeListsStack()

getContextNodes

public final DTMIterator getContextNodes()
Get the current context node list.

Returns: An iterator for the current context list, as defined in XSLT.

getCurrentExpressionNode

public final int getCurrentExpressionNode()
Get the current node that is the expression's context (i.e. for current() support).

Returns: The current sub-expression node.

getCurrentExpressionNodeStack

public IntStack getCurrentExpressionNodeStack()

getCurrentNode

public final int getCurrentNode()
Get the current context node.

Returns: the current node.

getCurrentNodeList

public SubContextList getCurrentNodeList()
Get the current node list as defined by the XSLT spec.

Returns: the current node list.

UNKNOWN: internal

getCurrentNodeStack

public IntStack getCurrentNodeStack()

getDTM

public DTM getDTM(Source source, boolean unique, DTMWSFilter wsfilter, boolean incremental, boolean doIndexing)
Get an instance of a DTM, loaded with the content from the specified source. If the unique flag is true, a new instance will always be returned. Otherwise it is up to the DTMManager to return a new instance or an instance that it already created and may be being used by someone else. (I think more parameters will need to be added for error handling, and entity resolution).

Parameters: source the specification of the source object, which may be null, in which case it is assumed that node construction will take by some other means. unique true if the returned DTM must be unique, probably because it is going to be mutated. wsfilter Enables filtering of whitespace nodes, and may be null. incremental true if the construction should try and be incremental. doIndexing true if the caller considers it worth it to use indexing schemes.

Returns: a non-null DTM reference.

getDTM

public DTM getDTM(int nodeHandle)
Get an instance of a DTM that "owns" a node handle.

Parameters: nodeHandle the nodeHandle.

Returns: a non-null DTM reference.

getDTMHandleFromNode

public int getDTMHandleFromNode(Node node)
Given a W3C DOM node, try and return a DTM handle. Note: calling this may be non-optimal.

Parameters: node Non-null reference to a DOM node.

Returns: a valid DTM handle.

getDTMIdentity

public int getDTMIdentity(DTM dtm)
%TBD% Doc

getDTMManager

public DTMManager getDTMManager()
Return the DTMManager object. Though XPathContext context extends the DTMManager, it really is a proxy for the real DTMManager. If a caller needs to make a lot of calls to the DTMManager, it is faster if it gets the real one from this function.

getDTMXRTreeFrag

public DTMXRTreeFrag getDTMXRTreeFrag(int dtmIdentity)
Gets DTMXRTreeFrag object if one has already been created. Creates new DTMXRTreeFrag object and adds to m_DTMXRTreeFrags HashMap, otherwise.

Parameters: dtmIdentity

Returns: DTMXRTreeFrag

getErrorListener

public final ErrorListener getErrorListener()
Get the ErrorListener where errors and warnings are to be reported.

Returns: A non-null ErrorListener reference.

getExpressionContext

public ExpressionContext getExpressionContext()
The the expression context for extensions for this context.

Returns: An object that implements the ExpressionContext.

getGlobalRTFDTM

public DTM getGlobalRTFDTM()
Get a DTM to be used as a container for a global Result Tree Fragment. This will always be an instance of (derived from? equivalent to?) SAX2DTM, since each RTF is constructed by temporarily redirecting our SAX output to it. It may be a single DTM containing for multiple fragments, if the implementation supports that. Note: The distinction between this method and getRTFDTM() is that the latter allocates space from the dynamic variable stack (m_rtfdtm_stack), which may be pruned away again as the templates which defined those variables are exited. Global variables may be bound late (see XUnresolvedVariable), and never want to be discarded, hence we need to allocate them separately and don't actually need a stack to track them.

Returns: a non-null DTM reference.

getIteratorRoot

public final int getIteratorRoot()
Get the current location path iterator root.

getNamespaceContext

public final PrefixResolver getNamespaceContext()
Get the current namespace context for the xpath.

Returns: the current prefix resolver for resolving prefixes to namespace URLs.

getOwnerObject

public Object getOwnerObject()
Get the "owner" context of this context, which should be, in the case of XSLT, the Transformer object. This is needed so that XSLT functions can get the Transformer.

Returns: The owner object passed into the constructor, or null.

getPredicatePos

public final int getPredicatePos()

getPredicateRoot

public final int getPredicateRoot()
Get the current predicate root.

getPrimaryReader

public final XMLReader getPrimaryReader()
Get primary XMLReader associated with this execution context.

Returns: The reader of the primary source tree.

getRTFDTM

public DTM getRTFDTM()
Get a DTM to be used as a container for a dynamic Result Tree Fragment. This will always be an instance of (derived from? equivalent to?) SAX2DTM, since each RTF is constructed by temporarily redirecting our SAX output to it. It may be a single DTM containing for multiple fragments, if the implementation supports that.

Returns: a non-null DTM reference.

getSAXLocator

public SourceLocator getSAXLocator()
Get the current locater in the stylesheet.

Returns: The location within the stylesheet, or null if not known.

getSourceTreeManager

public final SourceTreeManager getSourceTreeManager()
Get the SourceTreeManager associated with this execution context.

Returns: the SourceTreeManager associated with this execution context.

getSubContextList

public SubContextList getSubContextList()
Get the current axes iterator, or return null if none.

Returns: the sub-context node list.

UNKNOWN: internal

getURIResolver

public final URIResolver getURIResolver()
Get the URIResolver associated with this execution context.

Returns: a URI resolver, which may be null.

getVarStack

public final VariableStack getVarStack()
Get the variable stack, which is in charge of variables and parameters.

Returns: the variable stack, which should not be null.

isSecureProcessing

public boolean isSecureProcessing()
Return the state of the secure processing feature

popContextNodeList

public final void popContextNodeList()
Pop the current context node list.

UNKNOWN: internal

popCurrentExpressionNode

public final void popCurrentExpressionNode()
Pop the current node that is the expression's context (i.e. for current() support).

popCurrentNode

public final void popCurrentNode()
Pop the current context node.

popCurrentNodeAndExpression

public final void popCurrentNodeAndExpression()
Set the current context node.

popExpressionState

public final void popExpressionState()
Pop the current context node, expression node, and prefix resolver.

popIteratorRoot

public final void popIteratorRoot()
Pop the current location path iterator root.

popNamespaceContext

public final void popNamespaceContext()
Pop the current namespace context for the xpath.

popPredicatePos

public final void popPredicatePos()

popPredicateRoot

public final void popPredicateRoot()
Pop the current predicate root.

popRTFContext

public void popRTFContext()
Pop the RTFDTM's context mark. This discards any RTFs added after the last mark was set. If there is no RTF DTM, there's nothing to pop so this becomes a no-op. If pushes were issued before this was called, we count on the fact that popRewindMark is defined such that overpopping just resets to empty. Complicating factor: We need to handle the case of popping back to a previous RTF DTM, if one of the weird produce-an-RTF-to-build-an-RTF cases arose. Basically: If pop says this DTM is now empty, then return to the previous if one exists, in whatever state we left it in. UGLY, but hopefully the situation which forces us to consider this will arise exceedingly rarely.

popSAXLocator

public void popSAXLocator()
Pop the current locater.

popSubContextList

public final void popSubContextList()
Pop the last pushed axes iterator.

UNKNOWN: internal

pushContextNodeList

public final void pushContextNodeList(DTMIterator nl)
Set the current context node list.

Parameters: nl the current node list, also refered to here as a context node list.

UNKNOWN: internal

pushCurrentExpressionNode

public final void pushCurrentExpressionNode(int n)
Set the current node that is the expression's context (i.e. for current() support).

Parameters: n The sub-expression node to be current.

pushCurrentNode

public final void pushCurrentNode(int n)
Set the current context node.

Parameters: n the current node.

pushCurrentNodeAndExpression

public final void pushCurrentNodeAndExpression(int cn, int en)
Set the current context node and expression node.

Parameters: cn the current node. en the sub-expression context node.

pushExpressionState

public final void pushExpressionState(int cn, int en, PrefixResolver nc)
Push the current context node, expression node, and prefix resolver.

Parameters: cn the current node. en the sub-expression context node. nc the namespace context (prefix resolver.

pushIteratorRoot

public final void pushIteratorRoot(int n)
Set the current location path iterator root.

pushNamespaceContext

public final void pushNamespaceContext(PrefixResolver pr)
Push a current namespace context for the xpath.

Parameters: pr the prefix resolver to be used for resolving prefixes to namespace URLs.

pushNamespaceContextNull

public final void pushNamespaceContextNull()
Just increment the namespace contest stack, so that setNamespaceContext can be used on the slot.

pushPredicatePos

public final void pushPredicatePos(int n)

pushPredicateRoot

public final void pushPredicateRoot(int n)
Set the current predicate root.

pushRTFContext

public void pushRTFContext()
Push the RTFDTM's context mark, to allows discarding RTFs added after this point. (If it doesn't exist we don't push, since we might still be able to get away with not creating it. That requires that excessive pops be harmless.)

pushSAXLocator

public void pushSAXLocator(SourceLocator location)
Set the current locater in the stylesheet.

Parameters: location The location within the stylesheet.

pushSAXLocatorNull

public void pushSAXLocatorNull()
Push a slot on the locations stack so that setSAXLocator can be repeatedly called.

pushSubContextList

public final void pushSubContextList(SubContextList iter)
Push a TreeWalker on the stack.

Parameters: iter A sub-context AxesWalker.

UNKNOWN: internal

release

public boolean release(DTM dtm, boolean shouldHardDelete)
Release a DTM either to a lru pool, or completely remove reference. DTMs without system IDs are always hard deleted. State: experimental.

Parameters: dtm The DTM to be released. shouldHardDelete True if the DTM should be removed no matter what.

Returns: true if the DTM was removed, false if it was put back in a lru pool.

reset

public void reset()
Reset for new run.

setAxesIteratorStackStacks

public void setAxesIteratorStackStacks(Stack s)

setContextNodeListsStack

public void setContextNodeListsStack(Stack s)

setCurrentExpressionNodeStack

public void setCurrentExpressionNodeStack(IntStack nv)

setCurrentNodeStack

public void setCurrentNodeStack(IntStack nv)

setErrorListener

public void setErrorListener(ErrorListener listener)
Set the ErrorListener where errors and warnings are to be reported.

Parameters: listener A non-null ErrorListener reference.

setNamespaceContext

public final void setNamespaceContext(PrefixResolver pr)
Get the current namespace context for the xpath.

Parameters: pr the prefix resolver to be used for resolving prefixes to namespace URLs.

setPrimaryReader

public void setPrimaryReader(XMLReader reader)
Set primary XMLReader associated with this execution context.

Parameters: reader The reader of the primary source tree.

setSAXLocator

public void setSAXLocator(SourceLocator location)
Set the current locater in the stylesheet.

Parameters: location The location within the stylesheet.

setSecureProcessing

public void setSecureProcessing(boolean flag)
Set the state of the secure processing feature

setSourceTreeManager

public void setSourceTreeManager(SourceTreeManager mgr)
Set the SourceTreeManager associated with this execution context.

Parameters: mgr the SourceTreeManager to be associated with this execution context.

setURIResolver

public void setURIResolver(URIResolver resolver)
Set the URIResolver associated with this execution context.

Parameters: resolver the URIResolver to be associated with this execution context, may be null to clear an already set resolver.

setVarStack

public final void setVarStack(VariableStack varStack)
Get the variable stack, which is in charge of variables and parameters.

Parameters: varStack non-null reference to the variable stack.

Copyright © 2005 Apache XML Project. All Rights Reserved.