/**
 * Logback: the reliable, generic, fast and flexible logging framework.
 * Copyright (C) 1999-2009, QOS.ch. All rights reserved.
 *
 * This program and the accompanying materials are dual-licensed under
 * either the terms of the Eclipse Public License v1.0 as published by
 * the Eclipse Foundation
 *
 *   or (per the licensee's choosing)
 *
 * under the terms of the GNU Lesser General Public License version 2.1
 * as published by the Free Software Foundation.
 */
package ch.qos.logback.access.pattern;

import ch.qos.logback.access.spi.IAccessEvent;
import ch.qos.logback.core.util.OptionHelper;


public class RequestAttributeConverter extends AccessConverter {

  String key;

  public void start() {
    key = getFirstOption();
    if (OptionHelper.isEmpty(key)) {
      addWarn("Missing key for the request attribute");
    } else {
      super.start();
    }
  }

  public String convert(IAccessEvent accessEvent) {
    if (!isStarted()) {
      return "INACTIVE_REQUEST_ATTRIB_CONV";
    }

    return accessEvent.getAttribute(key);
  }

}
