net.sf.saxon.expr.XPathContext Maven / Gradle / Ivy
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Copyright (c) 2013 Saxonica Limited.
// This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0.
// If a copy of the MPL was not distributed with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
// This Source Code Form is "Incompatible With Secondary Licenses", as defined by the Mozilla Public License, v. 2.0.
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
package net.sf.saxon.expr;
import net.sf.saxon.Configuration;
import net.sf.saxon.Controller;
import net.sf.saxon.event.Receiver;
import net.sf.saxon.event.SequenceReceiver;
import net.sf.saxon.expr.instruct.ParameterSet;
import net.sf.saxon.expr.sort.GroupIterator;
import net.sf.saxon.lib.ParseOptions;
import net.sf.saxon.lib.StringCollator;
import net.sf.saxon.om.*;
import net.sf.saxon.regex.RegexIterator;
import net.sf.saxon.trans.Mode;
import net.sf.saxon.trans.NoDynamicContextException;
import net.sf.saxon.trans.Rule;
import net.sf.saxon.trans.XPathException;
import net.sf.saxon.value.DateTimeValue;
import java.util.Iterator;
/**
* This class represents a context in which an XPath expression is evaluated.
*/
public interface XPathContext {
/**
* 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
* @return a new context, created as a copy of this context
*/
public XPathContextMajor newContext();
/**
* Construct a new context without copying (used for the context in a function call)
* @return a new clean context
*/
public XPathContextMajor newCleanContext();
/**
* Construct a new minor context. A minor context can only hold new values of the focus
* (currentIterator) and current output destination.
* @return a new minor context
*/
public XPathContextMinor newMinorContext();
/**
* Get the local (non-tunnel) parameters that were passed to the current function or template
* @return a ParameterSet containing the local parameters
*/
public ParameterSet getLocalParameters();
/**
* 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.
* @return a ParameterSet containing the tunnel parameters
*/
public ParameterSet getTunnelParameters();
/**
* Get the Controller. May return null when running outside XSLT or XQuery
* @return the controller for this query or transformation
*/
/*@Nullable*/
public Controller getController();
/**
* Get the Configuration
* @return the Saxon configuration object
*/
public Configuration getConfiguration();
/**
* Get the Name Pool
* @return the name pool
*/
public NamePool getNamePool();
/**
* Set the calling XPathContext
* @param caller the XPathContext of the calling expression
*/
public void setCaller(XPathContext caller);
/**
* 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.
* @return the XPathContext of the calling expression
*/
public XPathContext getCaller();
/**
* Set a new sequence iterator.
* @param iter the current iterator. The context item, position, and size are determined by reference
* to the current iterator.
*/
public void setCurrentIterator(SequenceIterator iter);
/**
* Get the current iterator.
* This encapsulates the context item, context position, and context size.
* @return the current iterator, or null if there is no current iterator
* (which means the context item, position, and size are undefined).
*/
public SequenceIterator getCurrentIterator();
/**
* Get the context item
* @return the context item, or null if the context item is undefined
*/
public Item getContextItem();
/**
* Get the context size (the position of the last item in the current node list)
* @return the context size
* @throws XPathException if the context position is undefined
*/
public int getLast() 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.
* @return true if the context position is the same as the context size.
*/
public boolean isAtLast() throws XPathException;
/**
* Get a named collation.
* Note: although collations are defined in the specification as being part of the static
* context, Saxon assumes that all available collations have global scope for a transformation
* or query, so that a collation URI can be translated into an actual collation without knowing
* where in the source code the collation URI was used. The default collation, however, can vary
* in different parts of a query or stylesheet, and expressions using the default collation must
* therefore get it from the static context.
* @param name the name (URI) of the required collation
* @return a StringCollator representing the collation
* @throws XPathException if the collation is not recognized
*/
public StringCollator getCollation(String name) 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
* @param parameterId Globally-unique parameter identifier
* @param slotNumber Slot number of the parameter within the stack frame of the called template
* @param isTunnel True if a tunnel parameter is required, else false
* @return ParameterSet.NOT_SUPPLIED, ParameterSet.SUPPLIED, or ParameterSet.SUPPLIED_AND_CHECKED
*/
public int useLocalParameter(
int parameterId, int slotNumber, boolean isTunnel) throws XPathException;
/**
* 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.
* @return array of variables.
*/
public StackFrame getStackFrame();
/**
* Get the value of a local variable, identified by its slot number
* @param slotnumber the slot number allocated at compile time to the variable,
* which identifies its position within the local stack frame
* @return the value of the variable.
*/
public Sequence evaluateLocalVariable(int slotnumber);
/**
* Set the value of a local variable, identified by its slot number
* @param slotnumber the slot number allocated at compile time to the variable,
* which identifies its position within the local stack frame
* @param value the value of the variable
*/
public void setLocalVariable(int slotnumber, Sequence value);
/**
* Set a new output destination, supplying the output format details.
* Note that it is the caller's responsibility to close the Writer after use.
*
* @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
* @param receiver the new output destination
* @param options options for schema-validation of the output stream. May be null
* if validation is not required (i.e. Validation.PRESERVE)
*/
public void changeOutputDestination(Receiver receiver, /*@Nullable*/ ParseOptions options) throws XPathException;
/**
* Ask whether the XSLT output state is "temporary" or "final"
* @return true to set temporary output state; false to set final output state
*/
public boolean isTemporaryOutputState();
/**
* Change the SequenceReceiver to which output is written
* @param receiver the SequenceReceiver to be used
*/
public void setReceiver(SequenceReceiver receiver);
/**
* Get the Receiver to which output is currently being written.
* @return the current SequenceReceiver
*/
public SequenceReceiver getReceiver();
/**
* Get the current mode.
* @return the current mode
*/
public Mode getCurrentMode();
/**
* Get the current template rule. This is used to support xsl:apply-imports and xsl:next-match
* @return the current template rule
*/
public Rule getCurrentTemplateRule();
/**
* Get the current group iterator. This supports the current-group() and
* current-grouping-key() functions in XSLT 2.0
* @return the current grouped collection
*/
public GroupIterator getCurrentGroupIterator();
/**
* Get the current regex iterator. This supports the functionality of the regex-group()
* function in XSLT 2.0.
* @return the current regular expressions iterator
*/
public RegexIterator getCurrentRegexIterator();
/**
* Get the current date and time
* @return the current date and time. All calls within a single query or transformation
* will return the same value
*/
public DateTimeValue getCurrentDateTime() throws NoDynamicContextException;
/**
* Get the implicit timezone
* @return 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.
*/
public int getImplicitTimezone() throws NoDynamicContextException;
/**
* Get the context stack. This method returns an iterator whose items are instances of
* {@link net.sf.saxon.trace.ContextStackFrame}, starting with the top-most stackframe and
* ending at the point the query or transformation was invoked by a calling application.
* @return an iterator over a copy of the run-time call stack
*/
public Iterator iterateStackFrames();
/**
* Get the current exception (in saxon:catch)
* @return the current exception, or null if there is none defined
*/
public XPathException getCurrentException();
public void notifyChildThreads() throws XPathException;
}
© 2015 - 2025 Weber Informatics LLC | Privacy Policy