Class AbstractTraceListener

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

public abstract class AbstractTraceListener extends StandardDiagnostics 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.
  • Field Details

    • indent

      protected int indent
    • out

      protected Logger out
  • Constructor Details

    • AbstractTraceListener

      public AbstractTraceListener()
  • Method Details

    • getCodeInjector

      public CodeInjector getCodeInjector()
      Get the associated CodeInjector to be used at compile time to generate the tracing calls
    • setLevelOfDetail

      public void setLevelOfDetail(int level)
      Set the level of detail required
      Parameters:
      level - 0=none, 1=low (function and template calls), 2=normal (instructions), 3=high (expressions)
    • open

      public void open(Controller controller)
      Called at start
      Specified by:
      open in interface TraceListener
      Parameters:
      controller - identifies the transformation controller, and provides the listener with access to context and configuration information
    • getOpeningAttributes

      protected abstract String getOpeningAttributes()
    • close

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

      public void enter(Traceable info, Map<String,Object> properties, 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.
      properties - extra information about the instruction to be included in the trace
      context - the XPath evaluation context
    • 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(Traceable info)
      Called after an instruction of the stylesheet got processed
      Specified by:
      leave in interface TraceListener
      Parameters:
      info -
    • isApplicable

      protected boolean isApplicable(Traceable info)
    • tag

      protected abstract String tag(Traceable info)
    • level

      protected int level(Traceable info)
    • 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.
    • spaces

      protected static String spaces(int n)
      Get n spaces
    • setOutputDestination

      public void setOutputDestination(Logger stream)
      Set the output destination (default is System.err)
      Specified by:
      setOutputDestination in interface TraceListener
      Parameters:
      stream - the output destination for tracing output
    • getOutputDestination

      public Logger getOutputDestination()
      Get the output destination
    • endRuleSearch

      public void endRuleSearch(Object rule, Mode mode, Item item)
      Method called when a rule search has completed.
      Specified by:
      endRuleSearch in interface TraceListener
      Parameters:
      rule - the rule (or possible built-in ruleset) that has been selected
      mode - the mode in operation
      item - the item that was checked against
    • startRuleSearch

      public void startRuleSearch()
      Method called when a search for a template rule is about to start
      Specified by:
      startRuleSearch in interface TraceListener