net.sf.saxon.expr

Interface XPathContext

All Known Implementing Classes:

EarlyEvaluationContext, XPathContextMajor, XPathContextMinor

public interface XPathContext

This class represents a context in which an XPath expression is evaluated.

Method Summary

Modifier and Type	Method and Description
Sequence<?>	evaluateLocalVariable(int slotnumber) Get the value of a local variable, identified by its slot number
XPathContext	getCaller() Get the calling XPathContext (the next one down the stack).
Configuration	getConfiguration() Get the Configuration
Item<?>	getContextItem() Get the context item
Controller	getController() Get the Controller.
Component	getCurrentComponent() Get the current component
DateTimeValue	getCurrentDateTime() Get the current date and time
XPathException	getCurrentException() Get the current exception (in saxon:catch)
GroupIterator	getCurrentGroupIterator() Get the current group iterator.
FocusIterator<?>	getCurrentIterator() Get the current iterator.
GroupIterator	getCurrentMergeGroupIterator() Get the current merge group iterator.
Component.M	getCurrentMode() Get the current mode.
java.lang.String	getCurrentOutputUri() Get the current output URI
RegexIterator	getCurrentRegexIterator() Get the current regex iterator.
Rule	getCurrentTemplateRule() Get the current template rule.
UnfailingErrorListener	getErrorListener() Get the error listener.
int	getImplicitTimezone() Get the implicit timezone
int	getLast() Get the context size (the position of the last item in the current node list)
ParameterSet	getLocalParameters() Get the local (non-tunnel) parameters that were passed to the current function or template
NamePool	getNamePool() Get the Name Pool
Receiver	getReceiver() Get the Receiver to which output is currently being written.
StackFrame	getStackFrame() Get a reference to the local stack frame for variables.
Component	getTargetComponent(int bindingSlot) Bind a component reference to a component.
int	getTemporaryOutputState() Ask whether the XSLT output state is "temporary" or "final"
XPathContextMajor.ThreadManager	getThreadManager() Get the thread manager used to process asynchronous xsl:result-document threads.
ParameterSet	getTunnelParameters() Get the tunnel parameters that were passed to the current function or template.
javax.xml.transform.URIResolver	getURIResolver() Get the URI resolver.
boolean	isAtLast() Determine whether the context position is the same as the context size that is, whether position()=last().
java.util.Iterator	iterateStackFrames() Get the context stack.
XPathContextMajor	newCleanContext() Construct a new context without copying (used for the context in a function call)
XPathContextMajor	newContext() Construct a new context as a copy of another.
XPathContextMinor	newMinorContext() Construct a new minor context.
void	setCaller(XPathContext caller) Set the calling XPathContext
void	setCurrentIterator(FocusIterator<?> iter) Set a new sequence iterator.
void	setCurrentOutputUri(java.lang.String uri) Set the current output URI
void	setLocalVariable(int slotNumber, Sequence<?> value) Set the value of a local variable, identified by its slot number
void	setReceiver(Receiver receiver) Change the SequenceReceiver to which output is written
void	setTemporaryOutputState(int temporary) Set the XSLT output state to "temporary" or "final"
<T extends Item<?>> FocusIterator<T>	trackFocus(SequenceIterator<T> iter) Create, set, and return a focus tracking iterator that wraps a supplied sequence iterator.
int	useLocalParameter(StructuredQName parameterId, int slotNumber, boolean isTunnel) Use local parameter.
void	waitForChildThreads() Wait for child threads started under the control of this context to finish.

Method Detail

newContext

XPathContextMajor newContext()

Construct a new context as a copy of another. The new context is effectively added to the top of a stack, and contains a pointer to the previous context

Returns:

a new context, created as a copy of this context

newCleanContext

XPathContextMajor newCleanContext()

Construct a new context without copying (used for the context in a function call)

Returns:

a new clean context

newMinorContext

XPathContextMinor newMinorContext()

Construct a new minor context. A minor context can only hold new values of the focus (currentIterator) and current output destination.

Returns:

a new minor context

getLocalParameters

ParameterSet getLocalParameters()

Get the local (non-tunnel) parameters that were passed to the current function or template

Returns:

a ParameterSet containing the local parameters

getTunnelParameters

ParameterSet getTunnelParameters()

Get the tunnel parameters that were passed to the current function or template. This includes all active tunnel parameters whether the current template uses them or not.

Returns:

a ParameterSet containing the tunnel parameters

getController

Controller getController()

Get the Controller. May return null when running outside XSLT or XQuery

Returns:

the controller for this query or transformation

getConfiguration

Configuration getConfiguration()

Get the Configuration

Returns:

the Saxon configuration object

getNamePool

NamePool getNamePool()

Get the Name Pool

Returns:

the name pool

setCaller

void setCaller(XPathContext caller)

Set the calling XPathContext

Parameters:

caller - the XPathContext of the calling expression

getCaller

XPathContext getCaller()

Get the calling XPathContext (the next one down the stack). This will be null if unknown, or if the bottom of the stack has been reached.

Returns:

the XPathContext of the calling expression

trackFocus

<T extends Item<?>> FocusIterator<T> trackFocus(SequenceIterator<T> iter)

Create, set, and return a focus tracking iterator that wraps a supplied sequence iterator.

Parameters:

iter - the current iterator. The context item, position, and size are determined by reference to the current iterator.

setCurrentIterator

void setCurrentIterator(FocusIterator<?> iter)

Set a new sequence iterator.

Parameters:

iter - the current iterator. The context item, position, and size are determined by reference to the current iterator.

getCurrentIterator

FocusIterator<?> getCurrentIterator()

Get the current iterator. This encapsulates the context item, context position, and context size.

Returns:

the current iterator, or null if there is no current iterator (which means the context item, position, and size are undefined).

getContextItem

Item<?> getContextItem()

Get the context item

Returns:

the context item, or null if the context item is undefined

getLast

int getLast()
     throws XPathException

Get the context size (the position of the last item in the current node list)

Returns:

the context size

Throws:

XPathException - if the context position is undefined

isAtLast

boolean isAtLast()
          throws XPathException

Determine whether the context position is the same as the context size that is, whether position()=last(). In many cases this has better performance than a direct comparison, because it does not require reading to the end of the sequence.

Returns:

true if the context position is the same as the context size.

Throws:

XPathException

getURIResolver

javax.xml.transform.URIResolver getURIResolver()

Get the URI resolver. This gets the local URIResolver set in the XPathContext if there is one; if not, it gets the URIResolver from the Controller (which itself defaults to the one set in the Configuration).

Returns:

the user-supplied URI resolver if there is one, or null otherwise.

Since:

9.6

getErrorListener

UnfailingErrorListener getErrorListener()

Get the error listener. If no ErrorListener has been set locally, the ErrorListener in the Controller is returned; this in turn defaults to the ErrorListener set in the Configuration.

Returns:

the ErrorListener in use. Note that this is not necessarily the ErrorListener that was supplied by the caller; if that was not an UnfailingErrorListener, it will have been wrapped in a DelegatingErrorListener, and it is the DelegatingErrorListener that this method returns.

Since:

9.6

getCurrentComponent

Component getCurrentComponent()

Get the current component

useLocalParameter

int useLocalParameter(StructuredQName parameterId,
                      int slotNumber,
                      boolean isTunnel)
               throws XPathException

Use local parameter. This is called when a local xsl:param element is processed. If a parameter of the relevant name was supplied, it is bound to the xsl:param element. Otherwise the method returns false, so the xsl:param default will be evaluated

Parameters:

parameterId - Globally-unique parameter identifier

slotNumber - Slot number of the parameter within the stack frame of the called template

isTunnel - True if a tunnel parameter is required, else false

Returns:

ParameterSet.NOT_SUPPLIED, ParameterSet.SUPPLIED, or ParameterSet.SUPPLIED_AND_CHECKED

Throws:

XPathException

getStackFrame

StackFrame getStackFrame()

Get a reference to the local stack frame for variables. Note that it's the caller's job to make a local copy of this. This is used for creating a Closure containing a retained copy of the variables for delayed evaluation.

Returns:

array of variables.

evaluateLocalVariable

Sequence<?> evaluateLocalVariable(int slotnumber)

Get the value of a local variable, identified by its slot number

Parameters:

slotnumber - the slot number allocated at compile time to the variable, which identifies its position within the local stack frame

Returns:

the value of the variable.

setLocalVariable

void setLocalVariable(int slotNumber,
                      Sequence<?> value)
               throws XPathException

Set the value of a local variable, identified by its slot number

Parameters:

slotNumber - the slot number allocated at compile time to the variable, which identifies its position within the local stack frame

value - the value of the variable

Throws:

XPathException

setTemporaryOutputState

void setTemporaryOutputState(int temporary)

Set the XSLT output state to "temporary" or "final"

Parameters:

temporary - set non-zero to set temporary output state; zero to set final output state

getTemporaryOutputState

int getTemporaryOutputState()

Ask whether the XSLT output state is "temporary" or "final"

Returns:

non-zero if in temporary output state (integer identifies the state); zero if in final output state

setCurrentOutputUri

void setCurrentOutputUri(java.lang.String uri)

Set the current output URI

Parameters:

uri - the current output URI, or null if in temporary output state

getCurrentOutputUri

java.lang.String getCurrentOutputUri()

Get the current output URI

Returns:

the current output URI, or null if in temporary output state

setReceiver

void setReceiver(Receiver receiver)

Change the SequenceReceiver to which output is written

Parameters:

receiver - the SequenceReceiver to be used

getReceiver

Receiver getReceiver()

Get the Receiver to which output is currently being written.

Returns:

the current SequenceReceiver

getCurrentMode

Component.M getCurrentMode()

Get the current mode.

Returns:

the current mode

getCurrentTemplateRule

Rule getCurrentTemplateRule()

Get the current template rule. This is used to support xsl:apply-imports and xsl:next-match

Returns:

the current template rule

getCurrentGroupIterator

GroupIterator getCurrentGroupIterator()

Get the current group iterator. This supports the current-group() and current-grouping-key() functions in XSLT 2.0

Returns:

the current grouped collection

getCurrentMergeGroupIterator

GroupIterator getCurrentMergeGroupIterator()

Get the current merge group iterator. This supports the current-merge-group() and current-merge-key() functions in XSLT 2.0

Returns:

the current merge group

getCurrentRegexIterator

RegexIterator getCurrentRegexIterator()

Get the current regex iterator. This supports the functionality of the regex-group() function in XSLT 2.0.

Returns:

the current regular expressions iterator

getCurrentDateTime

DateTimeValue getCurrentDateTime()
                          throws NoDynamicContextException

Get the current date and time

Returns:

the current date and time. All calls within a single query or transformation will return the same value

Throws:

NoDynamicContextException

getImplicitTimezone

int getImplicitTimezone()

Get the implicit timezone

Returns:

the implicit timezone. This will be the timezone of the current date and time, and all calls within a single query or transformation will return the same value. The result is expressed as an offset from UTC in minutes. If the implicit timezone is unknown (which is the case when this is called on an EarlyEvaluationContext), return CalendarValue.NO_TIMEZONE

iterateStackFrames

java.util.Iterator iterateStackFrames()

Get the context stack. This method returns an iterator whose items are instances of ContextStackFrame, starting with the top-most stackframe and ending at the point the query or transformation was invoked by a calling application.

Returns:

an iterator over a copy of the run-time call stack

getCurrentException

XPathException getCurrentException()

Get the current exception (in saxon:catch)

Returns:

the current exception, or null if there is none defined

getThreadManager

XPathContextMajor.ThreadManager getThreadManager()

Get the thread manager used to process asynchronous xsl:result-document threads.

Returns:

the current thread manager; or null if multithreading is not supported

waitForChildThreads

void waitForChildThreads()
                  throws XPathException

Wait for child threads started under the control of this context to finish. This is called at the end of the (main thread of a) transformation, and also at the end of the "try" part of a try/catch. The threads affected are those used to implement xsl:result-document instructions.

Throws:

XPathException - if any of the child threads have failed with a dynamic error.

getTargetComponent

Component getTargetComponent(int bindingSlot)

Bind a component reference to a component. This is used for binding component references (such as function calls, global variable references, or xsl:call-template) across package boundaries. The binding is done dynamically because, in the presence of overridden components, the choice among different components with the same name depends on which package the caller is in.

Parameters:

bindingSlot - Binding slots are allocated statically to the external component references in every component: for example, in the case of a template, to all global variable references, named function calls, and named template calls within that template. The binding slot therefore identifies the name of the component that is required; and the selection of an actual component is done by selection from the binding vector of the component currently being executed

Returns:

the component to be invoked