public List <CustomizableFieldValue> CheckCustomizableFields(OCustomizableFieldEntities entity, CustomClass customFields,
                                                                     CollectionList customizableFieldsCollections, int linkId, char linkType)
        {
            List <CustomizableFieldValue> fieldValues = new List <CustomizableFieldValue>();

            var customizableFieldsServices = ServicesProvider.GetInstance().GetCustomizableFieldsServices();
            List <CustomizableField> customizableFields = customizableFieldsServices.
                                                          SelectCustomizableFields((int)Enum.Parse(typeof(OCustomizableFieldEntities), entity.ToString()));

            if (customizableFields != null)
            {
                foreach (CustomizableField field in customizableFields)
                {
                    CustomizableFieldValue customizableFieldValue = new CustomizableFieldValue {
                        Field = field
                    };

                    var fieldName = field.Name;
                    switch (field.Type)
                    {
                    case OCustomizableFieldTypes.Boolean:
                        customizableFieldValue.Value = ((bool)customFields.GetPropertyValueByName(fieldName)).ToString(CultureInfo.InvariantCulture);
                        break;

                    case OCustomizableFieldTypes.Number:
                        customizableFieldValue.Value = ((string)customFields.GetPropertyValueByName(fieldName));
                        break;

                    case OCustomizableFieldTypes.String:
                        customizableFieldValue.Value = (string)customFields.GetPropertyValueByName(fieldName);
                        break;

                    case OCustomizableFieldTypes.Date:
                        DateTime dateValue = (DateTime)customFields.GetPropertyValueByName(fieldName);
                        customizableFieldValue.Value = Converter.CustomFieldDateToString(dateValue);
                        break;

                    case OCustomizableFieldTypes.Client:
                        customizableFieldValue.Value = customFields.GetPropertyValueByName(fieldName).ToString();
                        break;

                    case OCustomizableFieldTypes.Collection:
                    {
                        int index = customizableFieldsCollections.GetItemIndexByName(fieldName, (string)customFields.GetPropertyValueByName(fieldName));
                        if (index != -1)
                        {
                            customizableFieldValue.Value = index.ToString(CultureInfo.InvariantCulture);
                        }
                    }
                    break;
                    }

                    var fieldType  = field.Type;
                    var fieldValue = customizableFieldValue.Value;
                    if (customizableFieldValue.Field.IsMandatory)
                    {
                        if (
                            (fieldType == OCustomizableFieldTypes.Number && fieldValue == string.Empty) ||
                            (fieldType == OCustomizableFieldTypes.String && fieldValue == string.Empty) ||
                            (fieldType == OCustomizableFieldTypes.Date && Converter.CustomFieldValueToDate(fieldValue) == DateTime.MinValue) ||
                            (fieldType == OCustomizableFieldTypes.Collection && fieldValue == null) ||
                            (fieldType == OCustomizableFieldTypes.Client && fieldValue == string.Empty)
                            )
                        {
                            throw new OpenCbsContractSaveException(OpenCbsContractSaveExceptionEnum.FieldIsMandatory);
                        }
                    }

                    if (fieldType == OCustomizableFieldTypes.Number)
                    {
                        if (fieldValue != string.Empty)
                        {
                            decimal result;
                            if (!Converter.CustomFieldDecimalParse(out result, fieldValue))
                            {
                                throw new OpenCbsContractSaveException(
                                          OpenCbsContractSaveExceptionEnum.NumberFieldIsNotANumber);
                            }
                        }
                    }

                    if (fieldType == OCustomizableFieldTypes.String)
                    {
                        if (fieldValue.Length > 300)
                        {
                            throw new OpenCbsCustomFieldNameException(OCustomFieldExceptionEnum.FieldLimited);
                        }
                    }

                    if (field.IsUnique)
                    {
                        if (
                            fieldType == OCustomizableFieldTypes.Number ||
                            fieldType == OCustomizableFieldTypes.String ||
                            fieldType == OCustomizableFieldTypes.Date ||
                            fieldType == OCustomizableFieldTypes.Client
                            )
                        {
                            if (customizableFieldsServices.FieldValueExists(linkId, linkType, customizableFieldValue.Field.Id, fieldValue))
                            {
                                throw new OpenCbsContractSaveException(OpenCbsContractSaveExceptionEnum.FieldIsNotUnique);
                            }
                        }
                    }

                    fieldValues.Add(customizableFieldValue);
                }
            }
            return(fieldValues);
        }