/**
   * Introspect our form bean configuration to identify the supported properties.
   *
   * @param config The FormBeanConfig instance describing the properties of the bean to be created
   * @exception IllegalArgumentException if the bean implementation class specified in the
   *     configuration is not DynaActionForm (or a subclass of DynaActionForm)
   */
  protected void introspect(FormBeanConfig config) {

    this.config = config;

    // Validate the ActionFormBean implementation class
    try {
      beanClass = RequestUtils.applicationClass(config.getType());
    } catch (Throwable t) {
      throw new IllegalArgumentException(
          "Cannot instantiate ActionFormBean class '" + config.getType() + "': " + t);
    }
    if (!DynaActionForm.class.isAssignableFrom(beanClass)) {
      throw new IllegalArgumentException(
          "Class '"
              + config.getType()
              + "' is not a subclass of "
              + "'org.apache.struts.action.DynaActionForm'");
    }

    // Set the name we will know ourselves by from the form bean name
    this.name = config.getName();

    // Look up the property descriptors for this bean class
    FormPropertyConfig descriptors[] = config.findFormPropertyConfigs();
    if (descriptors == null) {
      descriptors = new FormPropertyConfig[0];
    }

    // Create corresponding dynamic property definitions
    properties = new DynaProperty[descriptors.length];
    for (int i = 0; i < descriptors.length; i++) {
      properties[i] = new DynaProperty(descriptors[i].getName(), descriptors[i].getTypeClass());
      propertiesMap.put(properties[i].getName(), properties[i]);
    }
  }
  /**
   * Create an appropriate form bean in the appropriate scope, if one does not already exist.
   *
   * @param context FacesContext for the current request
   * @exception IllegalArgumentException if no ActionConfig for the specified action attribute can
   *     be located
   * @exception IllegalArgumentException if no FormBeanConfig for the specified form bean can be
   *     located
   * @exception IllegalArgumentException if no ModuleConfig can be located for this application
   *     module
   */
  public void createActionForm(FacesContext context) {

    // Look up the application module configuration information we need
    ModuleConfig moduleConfig = lookupModuleConfig(context);

    // Look up the ActionConfig we are processing
    String action = getAction();
    ActionConfig actionConfig = moduleConfig.findActionConfig(action);
    if (actionConfig == null) {
      throw new IllegalArgumentException("Cannot find action '" + action + "' configuration");
    }

    // Does this ActionConfig specify a form bean?
    String name = actionConfig.getName();
    if (name == null) {
      return;
    }

    // Look up the FormBeanConfig we are processing
    FormBeanConfig fbConfig = moduleConfig.findFormBeanConfig(name);
    if (fbConfig == null) {
      throw new IllegalArgumentException("Cannot find form bean '" + name + "' configuration");
    }

    // Does a usable form bean attribute already exist?
    String attribute = actionConfig.getAttribute();
    String scope = actionConfig.getScope();
    ActionForm instance = null;
    if ("request".equals(scope)) {
      instance = (ActionForm) context.getExternalContext().getRequestMap().get(attribute);
    } else if ("session".equals(scope)) {
      HttpSession session = (HttpSession) context.getExternalContext().getSession(true);
      instance = (ActionForm) context.getExternalContext().getSessionMap().get(attribute);
    }
    if (instance != null) {
      if (fbConfig.getDynamic()) {
        String className = ((DynaBean) instance).getDynaClass().getName();
        if (className.equals(fbConfig.getName())) {
          if (log.isDebugEnabled()) {
            log.debug(
                " Recycling existing DynaActionForm instance " + "of type '" + className + "'");
          }
          return;
        }
      } else {
        try {
          Class configClass = RequestUtils.applicationClass(fbConfig.getType());
          if (configClass.isAssignableFrom(instance.getClass())) {
            if (log.isDebugEnabled()) {
              log.debug(
                  " Recycling existing ActionForm instance "
                      + "of class '"
                      + instance.getClass().getName()
                      + "'");
            }
            return;
          }
        } catch (Throwable t) {
          throw new IllegalArgumentException(
              "Cannot load form bean class '" + fbConfig.getType() + "'");
        }
      }
    }

    // Create a new form bean instance
    if (fbConfig.getDynamic()) {
      try {
        DynaActionFormClass dynaClass = DynaActionFormClass.createDynaActionFormClass(fbConfig);
        instance = (ActionForm) dynaClass.newInstance();
        if (log.isDebugEnabled()) {
          log.debug(
              " Creating new DynaActionForm instance " + "of type '" + fbConfig.getType() + "'");
          log.trace(" --> " + instance);
        }
      } catch (Throwable t) {
        throw new IllegalArgumentException(
            "Cannot create form bean of type '" + fbConfig.getType() + "'");
      }
    } else {
      try {
        instance = (ActionForm) RequestUtils.applicationInstance(fbConfig.getType());
        if (log.isDebugEnabled()) {
          log.debug(" Creating new ActionForm instance " + "of type '" + fbConfig.getType() + "'");
          log.trace(" --> " + instance);
        }
      } catch (Throwable t) {
        throw new IllegalArgumentException(
            "Cannot create form bean of class '" + fbConfig.getType() + "'");
      }
    }

    // Configure and cache the form bean instance in the correct scope
    ActionServlet servlet =
        (ActionServlet)
            context.getExternalContext().getApplicationMap().get(Globals.ACTION_SERVLET_KEY);
    instance.setServlet(servlet);
    if ("request".equals(scope)) {
      context.getExternalContext().getRequestMap().put(attribute, instance);
    } else if ("session".equals(scope)) {
      context.getExternalContext().getSessionMap().put(attribute, instance);
    }
  }