// UnwrapLinks.java - Saxon extension for unwrapping nested linkspackage com.nwalsh.saxon;import java.util.Stack;import java.util.StringTokenizer;import org.xml.sax.*;import org.w3c.dom.*;import javax.xml.transform.TransformerException;import com.icl.saxon.Controller;import com.icl.saxon.expr.*;import com.icl.saxon.om.*;import com.icl.saxon.pattern.*;import com.icl.saxon.Context;import com.icl.saxon.tree.*;import com.icl.saxon.functions.Extensions;import com.nwalsh.saxon.UnwrapLinksEmitter;/** * <p>Saxon extension for unwrapping nested links</p> * * <p>$Id: UnwrapLinks.java,v 1.1 2002/06/26 11:02:05 nwalsh Exp $</p> * * <p>Copyright (C) 2000, 2002 Norman Walsh.</p> * * <p>This class provides a * <a href="http://saxon.sf.net/">Saxon 6.*</a> * implementation of a link unwrapper.</p> * * <p><b>Change Log:</b></p> * <dl> * <dt>1.0</dt> * <dd><p>Initial release.</p></dd> * </dl> * * @author Norman Walsh * <a href="mailto:ndw@nwalsh.com">ndw@nwalsh.com</a> * * @version $Id: UnwrapLinks.java,v 1.1 2002/06/26 11:02:05 nwalsh Exp $ * */public class UnwrapLinks {  /** True if the stylesheet is producing formatting objects */  private static boolean foStylesheet = false;  /**   * <p>Constructor for UnwrapLinks</p>   *   * <p>All of the methods are static, so the constructor does nothing.</p>   */  public UnwrapLinks() {  }  /**   * <p>Find the string value of a stylesheet variable or parameter</p>   *   * <p>Returns the string value of <code>varName</code> in the current   * <code>context</code>. Returns the empty string if the variable is   * not defined.</p>   *   * @param context The current stylesheet context   * @param varName The name of the variable (without the dollar sign)   *   * @return The string value of the variable   */  protected static String getVariable(Context context, String varName) {    Value variable = null;    String varString = null;    try {      variable = Extensions.evaluate(context, "$" + varName);      varString = variable.asString();      return varString;    } catch (TransformerException te) {      System.out.println("Undefined variable: " + varName);      return "";    } catch (IllegalArgumentException iae) {      System.out.println("Undefined variable: " + varName);      return "";    }  }  /**   * <p>Setup the parameters associated with unwrapping links</p>   *   * @param context The current stylesheet context   *   */  private static void setupUnwrapLinks(Context context) {    // Get the stylesheet type    String varString = getVariable(context, "stylesheet.result.type");    foStylesheet = (varString.equals("fo"));  }  /**   * <p>Unwrap links</p>   *   * @param rtf The result tree fragment of the verbatim environment.   *   * @return The modified result tree fragment.   */  public static NodeSetValue unwrapLinks (Context context,					  NodeSetValue rtf_ns) {    FragmentValue rtf = (FragmentValue) rtf_ns;    boolean tryAgain = true;    setupUnwrapLinks(context);    try {      Controller controller = context.getController();      NamePool namePool = controller.getNamePool();      while (tryAgain) {	UnwrapLinksEmitter ulEmitter = new UnwrapLinksEmitter(controller,							      namePool,							      foStylesheet);	rtf.replay(ulEmitter);	tryAgain = ulEmitter.tryAgain();	rtf = (FragmentValue) ulEmitter.getResultTreeFragment();      }      return rtf;    } catch (TransformerException e) {      // This "can't" happen.      System.out.println("Transformer Exception in unwrapLinks");      return rtf;    }  }}