Breaking Changes

Breaking Changes in the Release

Data Abstract for Delphi

  • Generation of specific update SQL for ORACLE was removed. for reverting old behavior add {$DEFINE DA3_ORACLE_SUPPORT} into and launch C:\Program Files (x86)\RemObjects Software\Build\install_DA.cmd with admin rights.

Breaking Changes in the Release

Remoting SDK for Delphi

  • breaking feature: generation of RODL in run-time from CodeFirst services was changed old behavior can be reverted via disabling CodeFirst_Use_RODL_Uses & CodeFirst_Generate_Abstract_Services in

Data Abstract for Delphi

  • Ancestor for TBaseLoginService was changed from TDataAbstractService to TBaseDataAbstractService.

Breaking Changes in the Release

Remoting SDK for .NET

  • Changed property names of the CustomCrossOriginEventArgs from Allow* to Allowed* to better reflect their purpose

Data Abstract for .NET

  • Changed visibility of the REST serializer:

    • Removed the RestMessage class
    • Changed visibility of the JsonRestMessage class to private
    • REST dispatcher: removed Message property
  • REST and OData dispatchers: Renamed Event Argument classes to conform to the .NET naming guidelines:

    • ODataOnGetServiceSchemaArgs to ODataGetServiceSchemaEventArgs
    • RestOnGetSchemaDataTableArgs to RestGetSchemaDataTableEventArgs
    • RestOnLoginNeededArgs to RestLoginNeededEventArgs
    • RestOnProcessTargetUrlArgs to RestProcessTargetUrlEventArgs
    • RestOnUnknownRequestArgs to RestUnknownRequestEventArgs
  • REST and OData dispatchers: Event handler types for corresponding events are now based on the EventHandler<T> type

These changes are a part of the planned integration of REST dispatcher into HttpAPI.

Breaking Changes in the Release

Data Abstract for Delphi

  • uDAActiveScriptProvider was removed

Breaking Changes in the Release

Remoting SDK for Delphi

  • Channels were renamed:
    • Indy prefix was added to Indy Super TCP channels:
      • TROSuperTCPServer -> TROIndySuperTCPServer
      • TROSuperTCPChannel -> TROIndySuperTCPChannel
    • Prefix of Synapse-based servers was changed from Ip with Synapse:
      • TROIpHTTPServer -> TROSynapseHTTPServer
      • TROIpSuperHTTPServer -> TROSynapseSuperHTTPServer
      • TROIpTCPServer -> TROSynapseTCPServer
  • TROIcsAsyncSuperTCPServer server was removed
  • Backward_compatibility define and all related aliases were removed.

Data Abstract for Delphi

Custom SQL macro (processing of custom SQL macro statement terms like {macro_name_here}, done via OnUnknownSqlMacroIdentifier event handler) is now DISABLED by default.

This is done for security reasons, as improper use of this feature (like allowing users to set values that will be later substituted as the macro value) results in SQL injection vulnerability.

Feature can be re-enabled by explicitly setting Data Service property AllowCustomSqlMacros to true. The default value of this property is false, which means that an exception will be raised if custom macro is encountered in the schema SQL statement.

Note: old name of this event is OnUnknownMacroVariable. this name wasn't removed for backward compatibility.

Breaking Changes in the May 2019 Release

Remoting SDK for Delphi

  • TROAsyncCallback declaration was changed. old:
TROAsyncCallback = procedure (const aRequest: IROAsyncRequest) of object;


{$IFDEF TROAsyncCallback_as_reqular_method}
TROAsyncCallback = procedure (const aRequest: IROAsyncRequest) of object;
TROAsyncCallback = {$IFDEF DELPHI2009UP}reference to{$ENDIF} 
                                         procedure (const aRequest: IROAsyncRequest);

for reverting old behavior, just declare TROAsyncCallback_as_reqular_method in your project or uncomment the same condition in

Breaking Changes in the The March 2019 Release

Remoting SDK for Delphi

  • TROUri.PathElements property was removed. workaround: use TROUri.ParsePathElements method instead of.
  • ReadVariantFromBinary/WriteVariantToBinary reads/writes varBoolean value as Integer instead of Byte. This change was made for compatibility with Remoting SDK for NET.

Streams with session, stored with TROSession.SaveToStream can not be read properly after this change.

Workaround: store boolean values into session as Integer like

Session.Values['xxx'] := Integer(ord(boolean_value));

and re-read/re-write such session streams before installing this release.

Breaking Changes in the November 2018 Releases

Data Abstract for Delphi

Parameter of the TDARemoteCommand.Execute method was changed from in to out direction:


function Execute(aCommandName: string; aInputParameters: DataParameterArray;aOutputParameters: DataParameterArray): Integer; override;


function Execute(aCommandName: string; aInputParameters: DataParameterArray;out aOutputParameters: DataParameterArray): Integer; override;

If you are using this overload method, workaround will be in not creating aOutputParameters.

old code:

lInput := DataParameterArray.Create;
lOutput := DataParameterArray.Create;
  // initializing input parameters
  DARemoveCommand.Execute(l_CommandName, lInput, lOutput);
  // processing output parameters

fixed code:

lInput := DataParameterArray.Create;
lOutput := nil; // changed
  // initializing input parameters
  DARemoveCommand.Execute(l_CommandName, lInput, lOutput);
  // processing output parameters

Breaking Changes in the October 2017 Releases

Remoting SDK for Delphi

We have introduced new types: ROAnsiString and ROUTF8String. They are aliases for String type and used as a replacement for legacy AnsiString/UTF8String. Since this version, codegen generates _Intf, _Invk and _Impl with these types. Notwithstanding, these types are written/read to stream as before. pay attention to last parameter:

    property fld_ansi: ROAnsiString read ffld_ansi write ffld_ansi;
    property fld_utf8: ROUTF8String read ffld_utf8 write ffld_utf8;
    __Serializer.WriteLegacyString('fld_ansi', l_fld_ansi, [paAsAnsiString]);
    __Serializer.WriteLegacyString('fld_utf8', l_fld_utf8, [paAsUTF8String]);

You may need to update method declarations in your _Impl if you have errors that some methods aren't found in _impl.

Breaking Changes in the April 2017 Releases

Remoting SDK for Delphi

TROSession class was updated and now it uses the TDictionary class for storing session values. this is applicable for Delphi XE6+ or Nextgen compiler. The TROSession.Keys property was added. old TROSession.Names property was deprecated.

Note: for using old implementation, uncomment ROUseGenerics in or add {$UNDEF ROUseGenerics} after {$I} line in uROSessions.pas

Breaking Changes in the March 2015 Releases

Remoting SDK for Delphi

TROProxy doesn't ignore RemoteService.ServiceName

as a result, this code:

RemoteService.ServiceName := 'ServiceA';
(RemoteService as IServiceB).MyMethod;

will call ServiceA.MyMethod instead of ServiceB.MyMethod as it was earlier.

possible problems: Unknown method XXXX for interface YYYY can be raised for working code.


  • validate that RemoteService.ServiceName specified correctly
  • revert old behavior via editing uROProxy.pas as:
constructor TROProxy.Create(const aRemoteService: IRORemoteService);
  Create(aRemoteService.Message, aRemoteService.Channel);
  fCloneMessage := aRemoteService.CloneMessage;
  //fInterfaceName := aRemoteService.ServiceName;

Breaking Changes in the June 2014 Releases

Remoting SDK for Delphi

  • D6 support were removed
  • Sources were split to
    • Client part
    • Server part
  • Encryption support (property of channels and servers) is installed only if legacy component is selected in setup. also it is affected to
    • RODEC folder
    • uROEncryption.pas
    • uROEncryptionEnvelope.pas
  • TROAESEncryptionEnvelope class were moved to uROAESEncryptionEnvelope.pas
  • <eventsink>_writer interface were moved from _intf to _invk file
  • ZeroConfHub support was removed:
    • uROZeroConfHub.pas
    • uROZeroConfHubSynapse.pas
    • uROZeroConfStreamWorker.pas

Data Abstract for Delphi

  • D6 support were removed
  • Sources were split to

    • Client part
    • Server part (files were moved to Server subfolder)
    • BaseLoginService_Impl.pas
    • Data AbstractService_Impl.pas
    • MultiDbLoginService_Impl.pas
    • MultiDbLoginServiceV5_Impl.pas
    • SimpleData AbstractService_Impl.pas
    • SimpleLoginService_Impl.pas
    • uDAADOInterfaces.pas
    • uDABusinessProcessor.pas
    • uDAConnectionManager.pas
    • uDAConnections.pas
    • uDADataDictionary.pas
    • uDADatasetWrapper.pas
    • uDADataTableReferenceCollection.pas
    • uDADB2Interfaces.pas
    • uDADBEventRepository.pas
    • uDADBSessionManager.pas
    • uDADiagrams.pas
    • uDADriverForeignKey.pas
    • uDADriverManager.pas
    • uDAEBaseDataset.pas
    • uDAEBaseStoredProcedure.pas
    • uDAEConnection.pas
    • uDAElevateDBInterfaces.pas
    • uDAEngine.pas
    • uDAESQLCommand.pas
    • uDAHelpers.pas
    • uDAHETConnections.pas
    • uDAHETDriver.pas
    • uDAIBInterfaces.pas
    • uDAJavaScriptHttpDispatcher.pas
    • uDALocalCommand.pas
    • uDALocalDataAdapter.pas
    • uDALocalHelpers.pas
    • uDAMySQLInterfaces.pas
    • uDANativeDatabaseAccessSupport.pas
    • uDAOData.pas
    • uDAODataDispatcher.pas
    • uDAODataGenerator.pas
    • uDAODataMetadata.pas
    • uDAOracleInterfaces.pas
    • uDAPostgresInterfaces.pas
    • uDAQueryBuilder.pas
    • uDASchema.pas
    • uDAScriptContext.pas
    • uDAServerLog.pas
    • uDASimpleDataStreamer.pas
    • uDASimpleQueryBuilder.pas
    • uDASQL92Interfaces.pas
    • uDASQL92QueryBuilder.pas
    • uDASQLiteInterfaces.pas
    • uDASQLMacroProcessor.pas
    • uDASybaseInterfaces.pas
    • uDAUnionDataset.pas
    • uDAUtils.pas
    • Legacy part (files were moved to Legacy subfolder):
    • DALoginService_Impl.pas
    • DARemoteService_Impl.pas
    • Data Abstract3_Async.pas
    • Data Abstract3_Intf.pas
    • Data Abstract3_Invk.pas
    • uDAActiveScriptProvider.pas
    • uDAADODataTable.pas
    • uDABinAdapter.pas
    • uDACache.pas
    • uDACDSDataTable.pas
    • uDADatasetProvider.pas
    • uDALegacySupport.pas
    • uDAMSScriptControl_TLB.pas
    • uDAObjAuto.pas
    • uDAPlainWhere.pas
    • uDAXMLAdapter.pas
  • some interfaces from uDAInterfaces.pas were moved to uDAServerInterfaces.pas

  • deprecated properties of TDADatatable were removed in favour of TDALocalDataAdapter:

    • LocalDAConnection
    • LocalSchema
    • LocalDataStreamer
    • LocalConnection
    • OnLocalUpdateDataBeginTransaction
    • OnLocalUpdateDataCommitTransaction
    • OnLocalUpdateDataRollBackTransaction
  • uDAClasses.pas unit was removed. content was moved to following files. Compiler can fail at compiling some forms. In this case, modify unit via adding a space in code or similar and save unit, IDE will add required units to uses section automatically.

    • uDACore.pas
    • uDAStreamableComponent.pas
    • uDAConnectionManager.pas
    • uDADataDictionary.pas
    • uDADiagrams.pas
    • uDAUpdateRule.pas
    • uDADatasetRelationship.pas
    • uDASchema.pas
  • some server-side properties of IDADataset interface were moved to IDAServerDataset. casting <IDADataset> as IDAServerDataset will return valid IDAServerDataset interface, e.g.

lsql := (ldataset as IDAServerDataset).SQL;
  • support of TDAWhere was removed from IDAServerDataset in favour DynamicWhere property. for backward compatibility is possible to set prepared where statement via IDALegacyWhereSupport interface as
(ldataset as IDALegacyWhereSupport).WhereClause := 'ID > 100'
  • support of TDAWhere was removed from TDADataTable. for backward compatibily, class helper for TDADataTable with Where property was added into uDAPlainWhere.pas

Internet Pack for .NET

  • The HttpRequestInvalidException exception class now accepts only System.Net.HttpStatusCode as Http status code instead of arbitrary integer values

Remoting SDK for .NET

Http Codes
  • Properties pair Code/Status that represents HTTP return code has been replaced with single property HttpCode of type System.Net.HttpStatusCode. Old properties are marked as obsolete and are still accessible. However it is strongly recommended to use the HttpCode property.
MasterServer support
  • Classes related to the MasterServer Session Manager were removed from Remoting SDK
Moved Classes And Interfaces
  • Interface IRodlProvider has been moved from namespace RemObjects.SDK.Server.Extensibility to namespace RemObjects.SDK.Server
  • Interface IServiceManagerExtender has been moved from namespace RemObjects.SDK.Server.Extensibility to namespace RemObjects.SDK.Server
Obsolete Methods and Properties
  • Property ComplexType.TypeName has been removed
  • Property Service.IsAbstract has been removed
Renamed Classes
  • Exception SessionsHasBeedDisposedException has been renamed to SessionDisposedException. Dummy exception class SessionsHasBeedDisposedException is still available as obsolete one.
Service Activation/Deactivation methods
  • Methods Service.Activate and Service.Deactivate are no longer virtual and cannot be overridden. Instead virtual protected methods Service.InternalActivate and Service.InternalDeactivate were introduced. This change was introduced to remove possibility of undefined behavior in case the Service.Activate and Service.Deactivate methods are overridden and their new implementation doesn't call the corresponding base method. Important: Do not call the base.Activate or base.Deactivate methods in their Internal* counterparts
Session And Event Management
  • Session properties LastAccessedTime and Created now return UTC time, not local
  • Remoting SDK now uses the ISessionManager interface to access the global session manager instead of the reference of the base SessionManager class type.
  • Remoting SDK now uses the IMessageQueueManager interface to access the global message queue manager instead of the reference of the base MessageQueueManager class type.
  • The IStremableSession interface has been removed.
  • The IEventNotification interface has been renamed to IEventDataProvider
  • Obsolete method void SessionManager.GetAllSessions(IList) has been removed. Method IList&lt;Guid&gt; SessionManager.GetAllSessions() should be used instead.
  • Unused method MessageQueueManager.ExpireSessions has been removed.
  • Remoting SDK now uses the IEventSinkManager interface to access the global session manager instead of the reference of the base EventSinkManager class type.
ZeroConf support
  • ROZeroConfHub has been phased out and is not shipped anymore
  • Enum ZeroConfEngine is now marked as obsolete. Please consider to remove all references to values of this type. This enumeration will be completely removed from Remoting SDK in the late 2014 releases.
  • Nested type RemObjects.SDK.ZeroConf.ZeroConfRegistration.ZeroConfRegistrationErrorArgs was moved out and is now named RemObjects.SDK.ZeroConf.ZeroConfRegistrationErrorArgs
  • Property ZeroConfRegistration.AutoStartZeroConfHub is now obsolete and will be completely removed from Remoting SDK in one of the late 2014 releases.

Data Abstract for .NET

  • The RemObjects.Data Abstract.Linq assembly has been merged into the RemObjects.Data Abstract assembly
  • The RemObjects.Data Abstract assembly now requires at least .NET 3.5
Business Processor
  • Event handler definition for the BeforeGetTableData event now requires sender ans 1st argument and is defined (for consistency reasons) as
method BeforeGetTableDataEventHandler = public delegate(sender: BusinessProcessor;  e: BeforeGetTableDataEventArgs);
Moved Classes: Local Data Adapters and Commands
  • The RemObjects.Data Abstract.LocalCommand (RemObjects.Data Abstract assembly) class has been moved to the RemObjects.Data Abstract.Server assembly
  • The RemObjects.Data Abstract.Linq.LinqLocalDataAdapter (RemObjects.Data Abstract.Linq assembly) class has been moved to the RemObjects.Data Abstract.Server assembly
  • The RemObjects.Data Abstract.LocalDataAdapter (RemObjects.Data Abstract assembly) class has been moved to the RemObjects.Data Abstract.Server assembly
  • The RemObjects.Data Abstract.IData AbstractLocalServiceAccess interface (RemObjects.Data Abstract assembly) has been moved to the RemObjects.Data Abstract.Server.IData AbstractLocalServiceAccess interface in the RemObjects.Data Abstract.Server assembly
  • The RemObjects.Data Abstract.Linq assembly is now a stub and there is no need to reference it.
Obsolete Classes, Methods and Properties
  • Obsolete class BaseLoginService.LoginString was finally removed. Use the RemObjects.Data Abstract.Server.LoginStringParser class instead.
  • Obsolete (and unused) SchemRelationship.RelationshipType property and corresponding enumeration type were removed
  • Obsolete (and unused) BusinessProcessor.IgnoreStaticCommands property was removed
  • Property BusinessProcessor.ServerEvents is no longer available in the designer
  • Bin1 Streamer was removed and is no longer available.
  • RemObjects.Data Abstract.Web assembly has been removed. Consider using ordinal Data Abstract infrastructure to access server data.
Renamed Classes and Enumerations
  • Enumeration RemoteDataAdapterStatus was renamed to DataAdapterStatus

Breaking Changes in the Fall 2012 Releases

Interface code needs regeneration for .NET projects in some cases

Since URL Schemes feature was introduced the code generation facility generates two additional constructors to allow convenient service Proxy instances creation passing System.Uri or URL string as a parameter. The generated code looks like this:

public partial class MegaDemoService_Proxy : RemObjects.SDK.Proxy, IMegaDemoService {
    // ...
    public MegaDemoService_Proxy(System.Uri aUri) :
            base(aUri) {
    public MegaDemoService_Proxy(string aUrl) :
            base(aUrl) {
    // ...

Affected users: Users who created a custom service hierarchy where the final service is derived from other custom service(s). This causes the corresponding proxy class to be derived from other custom proxy classes, not from the Proxy class directly.
Required actions: Regenerate the interface code for all RODL files used in the project or solution.

NOT affected users:

  • Users of platforms other than .NET
  • The majority of users who don't use custom inherited services
  • Data Abstract users who derive their services from Data Abstract built-in ones directly

Existing iOS projects must be linked against Security.framework

Since Remoting SDK for Xcode allows to deal with SSL certificates it requires the Security.framework API for internal operations. But iOS implementation is a static library and contains no linking information inside. New applications created with RO templates have all requred library references out-of-the-box.

Breaking Changes in the Summer 2012 Releases

RemoteService class property CloneMesage removed

Misspelled property CloneMesage was removed from the RemoteService. Please use the RemoteService.CloneMessage property instead.

Removed property was marked as obsolete since 2009.

Breaking Changes in the Spring 2012 Releases

Relativity Server Default Channel type changed to SuperHttp

Relativity default channel now registers itself as superhttp in ZeroConf environment, not as http like earliser.

This change does not break server access for existing Relativity clients because Relativity default channel now accepts both SimpleHttp and SuperHttp connections.

OlympiaServerSessionManager.GetAllSessions result changed

The OlympiaServerSessionManager.GetAllSession(IList) method now puts only session identifiers in the list provided instead of downloading entire sessions objects from the Olympia server as earlier.

It is highly recommended to use the strongly-typed IList<Guid> GetAllSession() method overload instead.

RemoteDataAdapter ReconcileDialog events changes

  • Obsolete RemoteDataAdapter.ShowReconcleDialog event was removed
  • RemoteDataAdapter.ShowReconcileDialog event handler signature changed from delegate(RemoteDataAdapter, DataSet, List, Boolean) to delegate(Object, ShowReconcleDialogEventArgs)
  • RemoteDataAdapter.ShowReconcileRecordInAppUI event handler signature changed from delegate(RemoteDataAdapter, DataSet, DeltaChange, Boolean, ReconcileDialogAction) to delegate(Object, ShowReconcileRecordInAppUIEventArgs)
  • Obsolete delegate types ShowReconcleDialogEventHandler and ShowReconcileRecordInAppUIEventHandler are no longer available

Breaking Changes in the Fall 2011 Releases

RemObjects.SDK.Server.Session class renamed to SessionRolesHelper

The RemObjects.SDK.Server.Session class has been renamed to RemObjects.SDK.Server.SessionRolesHelper and changed to be a static class. This change affects code that checked Session security roles using one of the RemObjects.SDK.Server.Session.ValidateRoles methods directly. Please consider using method Service.ServiceValidateRoles instead or fix code that called RemObjects.SDK.Server.Session.ValidateRoles by replacing RemObjects.SDK.Server.Session with RemObjects.SDK.Server.SessionRolesHelper.

Breaking Changes in the Winter 2010 Releases

Default port changed for the IpSuperHttpServerChannel

Default port was changed for the IpSuperHttpServerChannel server channel from 80 to 8099. This potentially affects Remoting SDK for .NET server applications created using pre-Winter 2010 releases if they were using IpSuperHttpServerChannel server channel on port 80. To resolve this, simply set port 80 in the Server Channel's properties explicitly, if you want to keep using this port.

Pre-compiled binaries for Hydra / Remoting SDK Integration

Starting from the Winter 2010 release we no longer provide pre-compiled *.bpl's for the Hydra - Remoting SDK Integration Library, in order to minimize build dependencies between the products. To use Remoting SDK for Delphi functionality in Hydra, you will need to manually compile and install Hydra_RO_D1* and Hydra_RO_IDE_D* into the Delphi IDE.

Poll Interval on ROEventReceiver in RO/Xcode now uses Seconds

For consistency with other Cocoa APIs, the poll interval setting on the ROEventReceiver is now specified in seconds, not milliseconds. If you were manually setting this value in code, your numbers might need adjustment to be 1/1000 of the values in use now.

Breaking Changes in the Summer 2010 Releases

Obsolete RemObjects.Common.Pooling namespace removed from RO/.NET

The obsolete namespace RemObjects.Common.Pooling was removed from Remoting SDK for .NET. This potentially affects Remoting SDK and Data Abstract for .NET server applications created using pre-Spring 2010 releases. Members of this namespace were used to specify PoolingBehavior for the ConnectionManager. Build error may occur in case non-default values like RaiseError or IgnoreAndReturn were used for this property. To resolve this error it is enough to just replace RemObjects.Common.Pooling with RemObjects.SDK.Pooling.

RemObjects.Common.Pooling had already been marked as "obsolete" and emitted warnings, in previous releases.

BPDX Channels Have Been Discontinued for RO/Delphi

As per request form the original author, we are no longer shipping the BPDX based server channels in Remoting SDK for Delphi, nor the underlying RO/DXSock libraries. This affects the \BPDX and \RODX folders of the source tree, as well as the RemObjects_RODX_* and RemObjects_BPDX_* packages.

If you are upgrading from a previous version of Remoting SDK, the source files will not be removed, and you can of course continue using them, while they still work with the current RO code base (Over time, and as Remoting SDK for Delphi adapts to newer versions of Delphi and different platforms supported by Delphi or FPC, they may cease working).

We recommend that users migrate to one of the other choices of channels we provide, such as Indy, Synapse or IP based channels.

We are working with the authors of DXSock to create new channels based on their latest DXSock 6.0, for a future release, but do not as of yet have a definitive timeline to announce.

RO/.NET Variant Serialization Incompatibly was Fixed

In Remoting SDK for .NET, the Variant class is designed to provide compatibility with the Delphi variant type. When the variant instance contains boolean value, it was erroneously (de)serialized as Int32 by error, i.e. the boolean value occupied 4 bytes in a stream. This was incompatible with the behavior of Remoting SDK for Delphi. This has been changed in the current release, so variants containing boolean values are now serialized as Byte occupying 1 byte in the stream.

Gthis change restores binary compatibility with Remoting SDK for Delphi (and also the new Variant support in Remoting SDK for Xcode added in this release, but may break in the unlikely event of variants being sent between .NET servers and .NET clients, if not both client and server are updated to use Summer 2010 release.

Breaking Changes in the Spring 2010 Releases

Method Signature Changes in Data Abstract for Xcode

The [DADataTable getDataTables*] methods have been changed to return an NSDictionary instead of an NSArray. We realize this is a breaking change, but given the relative newness of the DA/OX API and that a return value of an array was really quite unhelpful (there's no easy way to get at the appropriate tables by name), we decided this was worth changing now, while the product is still young.

Only the synchronous versions of the methods are affected.

Events Subscription and Compatibility between Delphi and .NET

This change is not really breaking, all existing functionality has been left intact. However, the explanations below are important to understand to succeed in cross-platform events implementation.


If you have used both Remoting SDK for Delphi and .NET simultaneously, you may have noticed that the callback events processing approach differs slightly and it was impossible to, for example, build a Delphi server that sends callback events to a .NET client application.

In this release we have fixed this problem, but discovered a security flaw in the Delphi events approach: the client application was allowed to manipulate with its own events subscription. It allows to create a malicious client application that will flood the server with millions of subscriptions causing the denial of service and the server has no ability to resist it. That's why we have decided to not propagate the Delphi events approach to the .NET side. The .NET approach has been implemented in RO SDK for Delphi instead.


  • Remoting SDK for .NET was not affected at all.
  • The LegacyEvents property of boolean type was added to the TROEventReceiver class. This property is true by default and allows to switch the receiver's operation mode from the legacy Delphi style to the new .NET style.
  • The LegacyEvents property of boolean type was added to the TRORemoteDataModule class. This property is true by default and when set to false disallows the self-subscription of events for the client applications.
Directions for developers
  • In order to provide compatibility between a Delphi client and a .NET server, the TROEventReceiver.LegacyEvents property must be set to false and the client application has to be recompiled with version 6.0.45 or later of Remoting SDK for Delphi.
  • To provide compatibility between a .NET client and a Delphi server, the server application must be recompiled with with version 6.0.45 or later. It is also advised to set the LegacyEvents property of the service implementation class to false if there are no legacy clients (ie clients written with prior versions of Remoting SDK for Delphi) connecting to the server.
  • Even in the single platform scenario (both client and server applications are Delphi-written), it is advised to set both mentioned properties to false and recompile both applications with the latest version of Remoting SDK. This will remove the events security flaw. NOTE: If the client application can't be upgraded for some reason, there is nothing to be done, because setting LegacyEvents to false on the server side will only make the server incompatible with legacy clients.
  • After the server upgrade it is vitally important to take control over the clients subscription/unsubscription on the server side. The TRORemoteDataModule.RegisterEventClient method must be called from inside the service before any events are sent to the client. The opposite method is TRORemoteDataModule.UnregisterEventClient. In the most common case, developers don't need to pay no attention to the unsubscription because the client will be unsubscribed automatically when its session dies.

Example (based on the File Broadcast sample of how to change the method in the FileBroadcastService_Impl.pas file:

procedure TFileBroadcastService.uploadfinished(const filename: Unicodestring; const filesize: Int64);
  // This line should be added so the event can reach the client:
  RegisterEventClient(GuidToString(ClientID), EID_FileEvents);
  (EventRepository as IFileEvents_Writer).OnNewFileAvailable(Session.SessionID, filename, filesize);

WideString vs UnicodeString types in Unicode versions of Delphi (2009 and later)


In Delphi 2009, a new data type for wide strings - UnicodeString was introduced, which is more efficient than the old WideString. During the migration Remoting SDK to Unicode, a mistake was made, and RODL codegen was not changed to use the new UnicodeString type (with an alias being provided for Delphi 2007 and below), as was intended; instead WideString was still used. Starting with the Spring 2010 releases, this has been rectified, and RODL-generated code now uses UnicodeString.


  • For fields, parameters and array elements in RODL with type WideString, generated code will now use UnicodeString type.
  • This will affect all auto-generated sources: interface, async interface and implementation files.
Directions for developers
  • For developers using Delphi 2007 or older, no change is required. Your Intf files will be rewritten to contain UnicodeString, but that is defined as an alias to WideString, and remains compatible.
  • For developers using Delphi 2009 or newer, you may need to manually adjust your Impl files (which are not updated automatically) to replace WideString with UnicodeString, to match regenerated Intf units.