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

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`void`	`changeOutputDestination(java.util.Properties props, javax.xml.transform.Result result, boolean isFinal, int hostLanguage, int validation, SchemaType schemaType)`	Set a new output destination, supplying the output format details.
`ValueRepresentation`	`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).
`StringCollator`	`getCollation(java.lang.String name)`	Get a named collation
`Configuration`	`getConfiguration()`	Get the Configuration
`Item`	`getContextItem()`	Get the context item
`int`	`getContextPosition()`	Get the context position (the position of the context item)
`Controller`	`getController()`	Get the Controller.
`DateTimeValue`	`getCurrentDateTime()`	Get the current date and time
`GroupIterator`	`getCurrentGroupIterator()`	Get the current group iterator.
`SequenceIterator`	`getCurrentIterator()`	Get the current iterator.
`Mode`	`getCurrentMode()`	Get the current mode.
`RegexIterator`	`getCurrentRegexIterator()`	Get the current regex iterator.
`Rule`	`getCurrentTemplateRule()`	Get the current template rule.
`StringCollator`	`getDefaultCollation()`	Get the default collation
`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
`InstructionInfo`	`getOrigin()`	Get information about the creating expression or other construct.
`int`	`getOriginatingConstructType()`	Get the type of location from which this context was created.
`SequenceReceiver`	`getReceiver()`	Get the Receiver to which output is currently being written.
`StackFrame`	`getStackFrame()`	Get a reference to the local stack frame for variables.
`ParameterSet`	`getTunnelParameters()`	Get the tunnel parameters that were passed to the current function or template.
`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(SequenceIterator iter)`	Set a new sequence iterator.
`void`	`setLocalVariable(int slotnumber, ValueRepresentation value)`	Set the value of a local variable, identified by its slot number
`void`	`setOrigin(InstructionInfo expr)`	Set the creating expression (for use in diagnostics).
`void`	`setOriginatingConstructType(int loc)`	Set the type of creating expression (for use in diagnostics).
`void`	`setReceiver(SequenceReceiver receiver)`	Change the SequenceReceiver to which output is written
`void`	`setTemporaryReceiver(SequenceReceiver out)`	Set the SequenceReceiver to which output is to be written, marking it as a temporary (non-final) output destination.
`boolean`	`useLocalParameter(StructuredQName qName, LocalParam binding, boolean isTunnel)`	Use local parameter.

- 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
  - setOrigin
```
void setOrigin(InstructionInfo expr)
```
    Set the creating expression (for use in diagnostics). The origin is generally set to "this" by the object that creates the new context. It's up to the debugger to determine whether this information is useful. Where possible, the object will be an Expression, allowing information about the calling instruction to be obtained.
    
    Parameters:
    
    expr - the expression that created this context object
  - setOriginatingConstructType
```
void setOriginatingConstructType(int loc)
```
    Set the type of creating expression (for use in diagnostics). When a new context is created, either this method or setOrigin(net.sf.saxon.trace.InstructionInfo) should be called.
    
    Parameters:
    
    loc - The originating location: the argument must be one of the integer constants in class Location
  - getOrigin
```
InstructionInfo getOrigin()
```
    Get information about the creating expression or other construct.
    
    Returns:
    
    information about the creating expression
  - getOriginatingConstructType
```
int getOriginatingConstructType()
```
    Get the type of location from which this context was created.
    
    Returns:
    
    the type of location. (The integer codes that are used are often fingerprints of instruction names, but not always. For details of the codes, see the standard trace listener which interprets them)
  - 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
  - setCurrentIterator
```
void setCurrentIterator(SequenceIterator 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
```
SequenceIterator 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).
  - getContextPosition
```
int getContextPosition()
                throws XPathException
```
    Get the context position (the position of the context item)
    
    Returns:
    
    the context position (starting at one)
    
    Throws:
    
    XPathException - if the context position is 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
  - getCollation
```
StringCollator getCollation(java.lang.String name)
                     throws XPathException
```
    Get a named collation
    
    Parameters:
    
    name - the name (URI) of the required collation
    
    Returns:
    
    a StringCollator representing the collation
    
    Throws:
    
    XPathException - if the collation is not recognized
  - getDefaultCollation
```
StringCollator getDefaultCollation()
```
    Get the default collation
    
    Returns:
    
    a StringCollator representing the default collation
  - useLocalParameter
```
boolean useLocalParameter(StructuredQName qName,
                          LocalParam binding,
                          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:
    
    qName - The fingerprint of the parameter name
    
    binding - The XSLParam element to bind its value to
    
    isTunnel - True if a tunnel parameter is required, else false
    
    Returns:
    
    true if a parameter of this name was supplied, false if not
    
    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
```
ValueRepresentation 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,
                      ValueRepresentation value)
```
    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
  - changeOutputDestination
```
void changeOutputDestination(java.util.Properties props,
                             javax.xml.transform.Result result,
                             boolean isFinal,
                             int hostLanguage,
                             int validation,
                             SchemaType schemaType)
                      throws XPathException
```
    Set a new output destination, supplying the output format details.
    Note that it is the caller's responsibility to close the Writer after use.
    
    Parameters:
    
    props - properties defining the output format
    
    result - Details of the new output destination
    
    isFinal - true if the destination is a final result tree (either the principal output or a secondary result tree); false if not
    
    hostLanguage - typically XSLT or XQuery
    
    validation - validation mode: strict, lax, preserve, or strip
    
    schemaType - type against which the output must be validated
    
    Throws:
    
    XPathException - if any dynamic error occurs; and specifically, if an attempt is made to switch to a final output destination while writing a temporary tree or sequence
  - setTemporaryReceiver
```
void setTemporaryReceiver(SequenceReceiver out)
```
    Set the SequenceReceiver to which output is to be written, marking it as a temporary (non-final) output destination.
    
    Parameters:
    
    out - The SequenceReceiver to be used
  - setReceiver
```
void setReceiver(SequenceReceiver receiver)
```
    Change the SequenceReceiver to which output is written
    
    Parameters:
    
    receiver - the SequenceReceiver to be used
  - getReceiver
```
SequenceReceiver getReceiver()
```
    Get the Receiver to which output is currently being written.
    
    Returns:
    
    the current SequenceReceiver
  - getCurrentMode
```
Mode 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
  - 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()
                 throws NoDynamicContextException
```
    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.
    
    Throws:
    
    NoDynamicContextException
  - 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

Interface XPathContext

Method Summary

Method Detail

newContext

newCleanContext

newMinorContext

getLocalParameters

getTunnelParameters

setOrigin

setOriginatingConstructType

getOrigin

getOriginatingConstructType

getController

getConfiguration

getNamePool

setCaller

getCaller

setCurrentIterator

getCurrentIterator

getContextPosition

getContextItem

getLast

isAtLast

getCollation

getDefaultCollation

useLocalParameter

getStackFrame

evaluateLocalVariable

setLocalVariable

changeOutputDestination

setTemporaryReceiver

setReceiver

getReceiver

getCurrentMode

getCurrentTemplateRule

getCurrentGroupIterator

getCurrentRegexIterator

getCurrentDateTime

getImplicitTimezone

iterateStackFrames