RegexViewManager.java :  » Web-Framework » vraptor » org » vraptor » view » Java Open Source

package org.vraptor.view;

import java.io.IOException;

import javax.servlet.ServletException;

import org.apache.log4j.Logger;
import org.vraptor.LogicRequest;

/**
 * Regex based view manager.
 * 
 * @author Guilherme Silveira
 */
public class RegexViewManager implements ViewManager {

  private static final Logger LOG = Logger.getLogger(RegexViewManager.class);

  private final String replacement;

  private final String regex = ("(.*);(.*);(.*)");

  /**
   * Instantiates the regex view manager with this replacement string.
   * 
   * @param replacement
   *            the replacement string
   */
  public RegexViewManager(String replacement) {

    this.replacement = translateExpression(replacement);
  }

  /**
   * Method replaces any $component with $1, $logic with $2 and $result with
   * $3 within the string.
   * 
   * @param replacement
   *            the string to replace
   * @return the translated string
   */
  String translateExpression(String replacement) {
    if (replacement != null && replacement.matches(".*(\\$component|\\$logic|\\$result).*")) {
      replacement = replacement.replaceAll("\\$component", "\\$1").replaceAll("\\$logic", "\\$2").replaceAll(
          "\\$result", "\\$3");
    }
    return replacement;
  }

  /**
   * 
   * @see org.vraptor.view.ViewManager#getForward(org.vraptor.LogicRequest,
   *      java.lang.String)
   */
  private String getForward(LogicRequest request, String result) throws ViewException {
    String value = request.getRequestInfo().getComponentName() + ";" + request.getRequestInfo().getLogicName()
        + ";" + result;
    return value.replaceAll(regex, replacement);

  }

  public void forward(LogicRequest logicRequest, String result) throws ViewException {
    String forward = getForward(logicRequest, result);
    directForward(logicRequest, result, forward);
  }

  public void directForward(LogicRequest logicRequest, String result, String forwardUrl) throws ViewException {
    LOG.debug("Server-side redirect to: " + forwardUrl);
    try {
      logicRequest.getRequest().getRequestDispatcher(forwardUrl).forward(logicRequest.getRequest(),
          logicRequest.getResponse());
    } catch (ServletException ex) {
      if (ex.getCause() != null) {
        throw new ViewException(ex.getCause());
      }
      throw new ViewException(ex);
    } catch (IOException ex) {
      throw new ViewException(ex);
    }
  }

  public void redirect(LogicRequest logicRequest, String url) throws ViewException {
    LOG.debug("Client-side redirect to: " + url);
    try {
      logicRequest.getResponse().sendRedirect(url);
    } catch (IOException e) {
      throw new ViewException(e);
    }
  }

}