Class AbstractTraceListener

java.lang.Object
net.sf.saxon.trace.AbstractTraceListener
All Implemented Interfaces:
EventListener, TraceListener
Direct Known Subclasses:
XQueryTraceListener, XSLTTraceListener

public abstract class AbstractTraceListener extends Object implements TraceListener
This is the standard trace listener used when the -T option is specified on the command line. There are two variants, represented by subclasses: one for XSLT, and one for XQuery. The two variants differ in that they present the trace output in terms of constructs used in the relevant host language.
  • Constructor Details

    • AbstractTraceListener

      public AbstractTraceListener()
  • Method Details

    • open

      public void open()
      Called at start
      Specified by:
      open in interface TraceListener
    • getOpeningAttributes

      protected abstract String getOpeningAttributes()
    • close

      public void close()
      Called at end
      Specified by:
      close in interface TraceListener
    • enter

      public void enter(InstructionInfo info, XPathContext context)
      Called when an instruction in the stylesheet gets processed
      Specified by:
      enter in interface TraceListener
      Parameters:
      info - gives information about the instruction being executed, and about the context in which it is executed. This object is mutable, so if information from the InstructionInfo is to be retained, it must be copied.
    • escape

      public String escape(String in)
      Escape a string for XML output (in an attribute delimited by double quotes). This method also collapses whitespace (since the value may be an XPath expression that was originally written over several lines).
    • leave

      public void leave(InstructionInfo info)
      Called after an instruction of the stylesheet got processed
      Specified by:
      leave in interface TraceListener
      Parameters:
      info - gives the same information that was supplied to the enter method, though it is not necessarily the same object. Note that the line number of the instruction is that of the start tag in the source stylesheet, not the line number of the end tag.
    • tag

      protected abstract String tag(int construct)
    • startCurrentItem

      public void startCurrentItem(Item item)
      Called when an item becomes the context item
      Specified by:
      startCurrentItem in interface TraceListener
      Parameters:
      item - the new current item. Item objects are not mutable; it is safe to retain a reference to the Item for later use.
    • endCurrentItem

      public void endCurrentItem(Item item)
      Called after a node of the source tree got processed
      Specified by:
      endCurrentItem in interface TraceListener
      Parameters:
      item - the item that was current, whose processing is now complete. This will represent the same underlying item as the corresponding startCurrentItem() call, though it will not necessarily be the same actual object.
    • setOutputDestination

      public void setOutputDestination(PrintStream stream)
      Set the output destination (default is System.err)
      Parameters:
      stream - the output destination for tracing output
    • getOutputDestination

      public PrintStream getOutputDestination()
      Get the output destination