Class NGCCRuntime

java.lang.Object
com.sun.xml.xsom.impl.parser.state.NGCCRuntime
All Implemented Interfaces:
NGCCEventSource, ContentHandler
Direct Known Subclasses:
NGCCRuntimeEx

public class NGCCRuntime extends Object implements ContentHandler, NGCCEventSource
Runtime Engine for RELAXNGCC execution. This class has the following functionalities:
  1. Managing a stack of NGCCHandler objects and switching between them appropriately.
  2. Keep track of all Attributes.
  3. manage mapping between namespace URIs and prefixes.
  4. TODO: provide support for interleaving.
Version:
$Id: NGCCRuntime.java,v 1.15 2002/09/29 02:55:48 okajima Exp $
  • Field Details

    • locator

      private Locator locator
    • attStack

      private final Stack attStack
      stack of Attributes.
    • currentAtts

      private AttributesImpl currentAtts
      current attributes set. always equal to attStack.peek()
    • text

      private StringBuffer text
      accumulated text.
    • currentHandler

      private NGCCEventReceiver currentHandler
      The current NGCCHandler. Always equals to handlerStack.peek()
    • IMPOSSIBLE

      static final String IMPOSSIBLE
      Impossible token. This value can never be a valid XML name.
      See Also:
    • redirect

      private ContentHandler redirect
      When redirecting a sub-tree, this value will be non-null.
    • redirectionDepth

      private int redirectionDepth
      Counts the depth of the elements when we are re-directing a sub-tree to another ContentHandler.
    • namespaces

      private final ArrayList namespaces
      in-scope namespace mapping. namespaces[2n ] := prefix namespaces[2n+1] := namespace URI
    • nsEffectivePtr

      private int nsEffectivePtr
      Index on the namespaces array, which points to the top of the effective bindings. Because of the timing difference between the startPrefixMapping method and the execution of the corresponding actions, this value can be different from namespaces.size().

      For example, consider the following schema:

      
        <oneOrMore>
         <element name="foo"><empty/></element>
        </oneOrMore>
        code fragment X
        <element name="bob"/>
       
      Code fragment X is executed after we see a startElement event, but at this time the namespaces variable already include new namespace bindings declared on "bob".
    • nsEffectiveStack

      private final Stack nsEffectiveStack
      Stack to preserve old nsEffectivePtr values.
    • indent

      private int indent
    • needIndent

      private boolean needIndent
  • Constructor Details

    • NGCCRuntime

      public NGCCRuntime()
  • Method Details

    • setRootHandler

      public void setRootHandler(NGCCHandler rootHandler)
      Sets the root handler, which will be used to parse the root element.

      This method can be called right after the object is created or the reset method is called. You can't replace the root handler while parsing is in progress.

      Usually a generated class that corresponds to the <start> pattern will be used as the root handler, but any NGCCHandler can be a root handler.

      Throws:
      IllegalStateException - If this method is called but it doesn't satisfy the pre-condition stated above.
    • reset

      public void reset()
      Cleans up all the data structure so that the object can be reused later. Normally, applications do not need to call this method directly, as the runtime resets itself after the endDocument method.
    • setDocumentLocator

      public void setDocumentLocator(Locator _loc)
      Specified by:
      setDocumentLocator in interface ContentHandler
    • getLocator

      public Locator getLocator()
      Gets the source location of the current event.

      One can call this method from RelaxNGCC handlers to access the line number information. Note that to

    • getCurrentAttributes

      public Attributes getCurrentAttributes()
      Attributes that belong to the current element.

      It's generally not recommended for applications to use this method. RelaxNGCC internally removes processed attributes, so this doesn't correctly reflect all the attributes an element carries.

    • replace

      public int replace(NGCCEventReceiver o, NGCCEventReceiver n)
      Description copied from interface: NGCCEventSource
      Replaces an old handler with a new handler, and returns ID of the EventReceiver thread.
      Specified by:
      replace in interface NGCCEventSource
    • processPendingText

      private void processPendingText(boolean ignorable) throws SAXException
      Processes buffered text. This method will be called by the start/endElement event to process buffered text as a text event.

      Whitespace handling is a tricky business. Consider the following schema fragment:

      <element name="foo"> <choice> <element name="bar"><empty/></element> <text/> </choice> </element> Assume we hit the following instance: <foo> <bar/></foo> Then this first space needs to be ignored (for otherwise, we will end up treating this space as the match to <text/> and won't be able to process <bar>.) Now assume the following instance: <foo/> This time, we need to treat this empty string as a text, for otherwise we won't be able to accept this instance.

      This is very difficult to solve in general, but one seemingly easy solution is to use the type of next event. If a text is followed by a start tag, it follows from the constraint on RELAX NG that that text must be either whitespaces or a match to <text/>.

      On the contrary, if a text is followed by a end tag, then it cannot be whitespace unless the content model can accept empty, in which case sending a text event will be harmlessly ignored by the NGCCHandler.

      Thus this method take one parameter, which controls the behavior of this method.

      TODO: according to the constraint of RELAX NG, if characters follow an end tag, then they must be either whitespaces or must match to <text/>.

      Parameters:
      possiblyWhitespace - True if the buffered character can be ignorabale. False if it needs to be consumed.
      Throws:
      SAXException
    • processList

      public void processList(String str) throws SAXException
      Throws:
      SAXException
    • startElement

      public void startElement(String uri, String localname, String qname, Attributes atts) throws SAXException
      Specified by:
      startElement in interface ContentHandler
      Throws:
      SAXException
    • onEnterElementConsumed

      public void onEnterElementConsumed(String uri, String localName, String qname, Attributes atts) throws SAXException
      Called by the generated handler code when an enter element event is consumed.

      Pushes a new attribute set.

      Note that attributes are NOT pushed at the startElement method, because the processing of the enterElement event can trigger other attribute events and etc.

      This method will be called from one of handlers when it truely consumes the enterElement event.

      Throws:
      SAXException
    • onLeaveElementConsumed

      public void onLeaveElementConsumed(String uri, String localName, String qname) throws SAXException
      Throws:
      SAXException
    • endElement

      public void endElement(String uri, String localname, String qname) throws SAXException
      Specified by:
      endElement in interface ContentHandler
      Throws:
      SAXException
    • characters

      public void characters(char[] ch, int start, int length) throws SAXException
      Specified by:
      characters in interface ContentHandler
      Throws:
      SAXException
    • ignorableWhitespace

      public void ignorableWhitespace(char[] ch, int start, int length) throws SAXException
      Specified by:
      ignorableWhitespace in interface ContentHandler
      Throws:
      SAXException
    • getAttributeIndex

      public int getAttributeIndex(String uri, String localname)
    • consumeAttribute

      public void consumeAttribute(int index) throws SAXException
      Throws:
      SAXException
    • startPrefixMapping

      public void startPrefixMapping(String prefix, String uri) throws SAXException
      Specified by:
      startPrefixMapping in interface ContentHandler
      Throws:
      SAXException
    • endPrefixMapping

      public void endPrefixMapping(String prefix) throws SAXException
      Specified by:
      endPrefixMapping in interface ContentHandler
      Throws:
      SAXException
    • skippedEntity

      public void skippedEntity(String name) throws SAXException
      Specified by:
      skippedEntity in interface ContentHandler
      Throws:
      SAXException
    • processingInstruction

      public void processingInstruction(String target, String data) throws SAXException
      Specified by:
      processingInstruction in interface ContentHandler
      Throws:
      SAXException
    • endDocument

      public void endDocument() throws SAXException
      Specified by:
      endDocument in interface ContentHandler
      Throws:
      SAXException
    • startDocument

      public void startDocument()
      Specified by:
      startDocument in interface ContentHandler
    • sendEnterAttribute

      public void sendEnterAttribute(int threadId, String uri, String local, String qname) throws SAXException
      Specified by:
      sendEnterAttribute in interface NGCCEventSource
      Throws:
      SAXException
    • sendEnterElement

      public void sendEnterElement(int threadId, String uri, String local, String qname, Attributes atts) throws SAXException
      Description copied from interface: NGCCEventSource
      Sends an enter element event to the specified EventReceiver thread.
      Specified by:
      sendEnterElement in interface NGCCEventSource
      Throws:
      SAXException
    • sendLeaveAttribute

      public void sendLeaveAttribute(int threadId, String uri, String local, String qname) throws SAXException
      Specified by:
      sendLeaveAttribute in interface NGCCEventSource
      Throws:
      SAXException
    • sendLeaveElement

      public void sendLeaveElement(int threadId, String uri, String local, String qname) throws SAXException
      Specified by:
      sendLeaveElement in interface NGCCEventSource
      Throws:
      SAXException
    • sendText

      public void sendText(int threadId, String value) throws SAXException
      Specified by:
      sendText in interface NGCCEventSource
      Throws:
      SAXException
    • redirectSubtree

      public void redirectSubtree(ContentHandler child, String uri, String local, String qname) throws SAXException
      This method can be called only from the enterElement handler. The sub-tree rooted at the new element will be redirected to the specified ContentHandler.

      Currently active NGCCHandler will only receive the leaveElement event of the newly started element.

      Parameters:
      uri - ,local,qname Parameters passed to the enter element event. Used to simulate the startElement event for the new ContentHandler.
      Throws:
      SAXException
    • resolveNamespacePrefix

      public String resolveNamespacePrefix(String prefix)
    • unexpectedX

      protected void unexpectedX(String token) throws SAXException
      Throws:
      SAXException
    • printIndent

      private void printIndent()
    • trace

      public void trace(String s)
    • traceln

      public void traceln(String s)