// to be used in DAOImpl.update only
  public static void copySimpleProperties(ModelObject dest, ModelObject orig) {
    try {
      PropertyDescriptor srcDescriptors[] =
          BeanUtilsBean.getInstance().getPropertyUtils().getPropertyDescriptors(dest);
      for (PropertyDescriptor pd : srcDescriptors) {
        String name = pd.getName();
        if ("class".equals(name)) {
          continue;
        }
        if ("id".equals(name)) {
          // TODO hardcoded.  for update, never change Id field
          continue;
        }

        Class type = pd.getPropertyType();
        debug("copySimpleProperties--  name=" + name + ", type=" + type);
        if (Collection.class.isAssignableFrom(type)) {
          Field field = dest.getClass().getDeclaredField(name);
          if (MyPropertyUtil.isFieldCollectionOfModel(field)) {
            // ingore collection of Model
            continue;
          } else {

            PropertyUtils.setProperty(dest, name, PropertyUtils.getProperty(orig, name));
          }
        } else if (ModelObject.class.isAssignableFrom(type)) {
          // we do not support editing of associated object at this point
          // nor pointing to another associated object
          continue;
        } else {
          PropertyUtils.setProperty(dest, name, PropertyUtils.getProperty(orig, name));
        }
      }
    } catch (Exception e) {
      throw new RuntimeException(e);
    }
  }
  public PagingLoadResult<BeanObject> getPagingList(
      String modelName, Criteria criteria, List<String> wantedFields, PagingLoadConfig pgc) {
    List<BeanObject> list = new ArrayList<BeanObject>();

    Manager manager = getManager(modelName);
    String methodName = config.getListMethod(modelName);
    try {
      Method method =
          manager
              .getClass()
              .getMethod(methodName, new Class[] {int.class, int.class, Criteria.class});
      if (method == null) {
        throw new RuntimeException("Method with paging not found: " + methodName);
      }

      List ret = (List) method.invoke(manager, pgc.getOffset(), pgc.getLimit(), criteria);
      for (Iterator it = ret.iterator(); it.hasNext(); ) {
        ModelObject model = (ModelObject) it.next();
        try {
          Map<String, Object> props = getProperties(model, wantedFields);
          list.add(new BeanObject(model.getClass().getSimpleName(), props));
        } catch (IllegalAccessException e) {
          e.printStackTrace();
        } catch (InvocationTargetException e) {
          e.printStackTrace();
        } catch (NoSuchMethodException e) {
          e.printStackTrace();
        }
      }
    } catch (SecurityException e) {
      e.printStackTrace();
    } catch (IllegalArgumentException e) {
      e.printStackTrace();
    } catch (NoSuchMethodException e) {
      e.printStackTrace();
    } catch (IllegalAccessException e) {
      e.printStackTrace();
    } catch (InvocationTargetException e) {
      e.printStackTrace();
    }

    if (pgc.getSortInfo().getSortField() != null) {
      final String sortField = pgc.getSortInfo().getSortField();
      if (sortField != null) {
        Collections.sort(
            list,
            pgc.getSortInfo()
                .getSortDir()
                .comparator(
                    new Comparator() {
                      public int compare(Object o1, Object o2) {
                        Object s1 = ((BeanObject) o1).get(sortField);
                        Object s2 = ((BeanObject) o2).get(sortField);
                        if (s1 instanceof Comparable && s2 instanceof Comparable) {
                          return ((Comparable) s1).compareTo((Comparable) s2);
                        }
                        if (s1 != null && s2 != null) {
                          return s1.toString().compareTo(s2.toString());
                        } else if (s2 != null) {
                          return -1;
                        }
                        return 0;
                      }
                    }));
      }
    }

    return new BasePagingLoadResult(list, pgc.getOffset(), getCount(modelName, criteria));
  }
  // by default only copy simple fields and associated Object's Id, unless requested with
  // wantedFields
  public static Map<String, Object> to2Form(ModelObject obj, List<String> wantedFields)
      throws IllegalAccessException, InvocationTargetException, NoSuchMethodException {
    Map<String, Object> props = new HashMap<String, Object>();

    try {
      if (wantedFields == null) {
        Map<String, Object> res = new HashMap<String, Object>();
        PropertyDescriptor srcDescriptors[] =
            BeanUtilsBean.getInstance().getPropertyUtils().getPropertyDescriptors(obj);
        for (PropertyDescriptor pd : srcDescriptors) {
          String name = pd.getName();
          if ("class".equals(name)) {
            continue;
          }

          Class type = pd.getPropertyType();
          //	        	debug("to2Form-- name="+name+", type="+type+",
          // value="+PropertyUtils.getProperty(obj, name));

          if (ModelObject.class.isAssignableFrom(type)) {
            //	        		continue;
            // return associated object's id
            // OpenPersistenceManagerInViewFilter and lazy-loading works here
            ModelObject assoc = (ModelObject) PropertyUtils.getProperty(obj, name);
            if (assoc != null) {
              res.put(name, assoc.getModelId());
            }
          } else if (Set.class.isAssignableFrom(type)) {
            Field field = obj.getClass().getDeclaredField(name);
            if (MyPropertyUtil.isFieldCollectionOfModel(field)) {
              // ingore collection of Model
            } else {
              // TODO leon convert from org.datanucleus.sco.backed.HashSet to a normal HashSet
              // just to make it work, need refine
              Set t = (Set) PropertyUtils.getProperty(obj, name);
              Set t2 = new HashSet();
              if (t != null) {
                t2.addAll(t);
              }
              res.put(name, t2);
            }
          } else if (PropertyUtils.isReadable(obj, name)) {
            res.put(name, PropertyUtils.getProperty(obj, name));
          }
        }
        return res;
      } else {
        // not tested yet
        for (String wantedField : wantedFields) {
          String[] chainedNames = StringUtils.split(wantedField, "_");
          int i = 1, noOfNames = chainedNames.length;
          ModelObject curObj = obj;
          for (String name : chainedNames) {
            Object value = PropertyUtils.getProperty(curObj, name);
            if (i == noOfNames) {
              if (value instanceof ModelObject || value instanceof Collection) {
                throw new RuntimeException(
                    "reached the end of chainedNames but found no simple value");
              }
              if (value != null) {
                props.put(wantedField, value);
                break;
              }
            } else {
              if (value instanceof ModelObject) {
                curObj = (ModelObject) value;
              } else {
                throw new RuntimeException(
                    "not reached the end of chainedNames but found a simple value");
              }
            }
            i++;
          }
        }
      }

      return props;
    } catch (Exception ex) {
      throw new RuntimeException(ex);
    }
  }
  public static void form2To(ModelObject dest, Map<String, Object> orig) {

    debug("form2To-- props:" + orig);

    try {

      HashMap<String, Object> _props = new HashMap<String, Object>();

      PropertyDescriptor srcDescriptors[] =
          BeanUtilsBean.getInstance().getPropertyUtils().getPropertyDescriptors(dest);

      for (PropertyDescriptor pd : srcDescriptors) {
        String fn = pd.getName();
        if ("class".equals(fn)) {
          continue;
        }
        Class type = pd.getPropertyType();

        debug("fn:" + fn + " type:" + type);
        if (!orig.containsKey(fn)) {
          continue;
        }

        Object value = orig.get(fn);
        if (value == null) {
          _props.put(fn, value);
          continue;
        }

        if (ModelObject.class.isAssignableFrom(type)) {
          String bean = type.getSimpleName();
          if (value instanceof String) {
            // the value is ID
            debug("form2To-- type=" + type);
            ModelObject mo = (ModelObject) type.newInstance();
            mo.setModelId((String) value);
            //                    ModelObject mo = getModelObject(bean, (String)value);
            _props.put(fn, mo);
          } else if (value instanceof Map) {
            Map<String, Object> cprops = (Map<String, Object>) value;
            ModelObject mo = (ModelObject) type.newInstance();
            form2To(mo, cprops);
            _props.put(fn, mo);
          } else {
            throw new RuntimeException(
                "Unknown value type: " + value + "," + value.getClass() + " bean:" + bean);
          }
        } else if (Collection.class.isAssignableFrom(type)) {
          Collection col = null;
          if (value != null) {
            if (MyPropertyUtil.isFieldCollectionOfModel(dest.getClass().getDeclaredField(fn))) {
              // NOTE: this means always Add/Update child ModelObject separately
              continue;
            } else {
              //                      String bean = config.getItemType(obj.getModelName(), fn);
              if (value instanceof String) {
                col = (Collection) PropertyUtils.getProperty(dest, fn);
                String val = (String) value;
                if (((String) val).indexOf(",") > 0) {
                  // for properties like Goods.categoryIds which is internally list of String,
                  // and submitted in the format of comma-separated string
                  // TODO escape ","
                  String[] values = ConvertUtil.split(val, ",");
                  col.addAll(Arrays.asList(values));
                } else {
                  col.add(value);
                }

              } else if (value instanceof Collection) {

                Collection c = (Collection) value;
                col = (Collection) PropertyUtils.getProperty(dest, fn);
                debug("size: " + c.size());
                col.addAll(c);
                //                            _props.put(fn, c);
              }
            }

            //            		else {
            ////                      throw new RuntimeException("Unknown value type: " +
            // value+","+value.getClass()+" bean:"+bean);
            //              		 throw new RuntimeException("Unknown value type: " +
            // value+","+value.getClass());
            //                  }
          } else {
            // keep the old value
            col = (Collection) PropertyUtils.getProperty(dest, fn);
          }
          //                _props.put(fn, col);
        } else {
          _props.put(fn, value);
        }
      }

      debug("form2To-- _props:" + _props);

      BeanUtils.populate(dest, _props);

    } catch (Exception e) {
      e.printStackTrace();
    }
  }