TRODLLChannel

Overview

TRODLLChannel implements a channel that talks to Services located in a local DLL file.

The server must be a .dll created using the DLL Server New Project Template.

Location


 

constructor Create  override

Standard component constructor

constructor Create(aOwner: TComponent)

Parameters:

  • aOwner: Owner

ActiveClientID

property ActiveClientID: TGUID read write

ActiveEvents

Allows to support IROActiveEventChannel

property ActiveEvents: Boolean read write

Assign  override    (declared in TROTransportChannel)

Copies the contents of another, similar object.

procedure Assign(Source: TPersistent)

Parameters:

  • Source: Instance whose properties will be copied

AssignEvents  protected override

Copies the events of another, similar object.

procedure AssignEvents(aSource: TROTransportChannel)

Parameters:

  • aSource: Instance whose properties will be copied

AssignSpecificProperties  protected override

Copies the specific properties of another, similar object.

procedure AssignSpecificProperties(aSource: TROTransportChannel)

Parameters:

  • aSource: Instance whose properties will be copied

AsyncException  protected virtual    (declared in TROTransportChannel)

Notifies about an exception in an asynchronous mode.

procedure AsyncException(aAsyncInterface: IROAsyncInterface; AsyncException: Exception)

Parameters:

  • aAsyncInterface: Exception source
  • AsyncException: Exception data

BeforeDispatch  protected override

Allows an implimentation to do necessary preparatory actions (checking the readiness of the channel, restore session data, etc.).

procedure BeforeDispatch(aMessage: IROMessage)

Parameters:


Busy    (declared in TROTransportChannel)

Informs whether the channel is currently busy executing a remote request (true) or not (false). Most channels (except most notably the TROSuperTCPChannel) are only capable of performing one request at a time; if a second request is attempted while the channel is Busy, an EROChannelBusy exception will be raised.

property Busy: Boolean read

CallbackEvents  protected    (declared in TROBaseActiveEventChannel)

Sends event to each registered IROEventReceiver

procedure CallbackEvents(aData: TStream; aThread: TThread)

Parameters:

  • aData: Data stream
  • aThread: Working thread to process the event

ChangeServerLocator  protected virtual    (declared in TROTransportChannel)

procedure ChangeServerLocator(var aFaultStartLocatorIdx: Integer; var aRetry: Boolean; const aException: Exception)

Parameters:

  • aFaultStartLocatorIdx:
  • aRetry:
  • aException:

ChannelMatchingTargetUri    (declared in TROTransportChannel)

Creates a client channel instance with type, target host and target port matching the provided target Uri.
F.e. for provided uri supertcp://192.168.1.100:7020/bin this method will return an instance of the Super Tcp channel with target host set to 192.168.1.100 and port set to 7020.

class function ChannelMatchingTargetUri(const aUri: TROUri): TROTransportChannel

Parameters:

  • aUri: Server Uri

ChannelMatchingTargetUrl    (declared in TROTransportChannel)

class function ChannelMatchingTargetUrl(const aUrl: string): TROTransportChannel

Parameters:

  • aUrl:

CheckProperties  override

Validates channel properties

procedure CheckProperties

ClientId

Contains the Client ID.

property ClientId: TGUID read write

CurrentLocator    (declared in TROTransportChannel)

Returns which of the fail-over/load balancing servers configured in the ServerLocators is currently active. Depending on the DispatchOptions defined, this value might change with each request, or only if the current server fails.

property CurrentLocator: TROServerLocator read write

DecryptStream (TStream, TStream)  protected overload    (declared in TROBaseConnection)

Decrypt stream

procedure DecryptStream(const Source: TStream; const Dest: TStream)

Parameters:

  • Source: Source
  • Dest: Destination

DecryptStream (TStream)  protected overload    (declared in TROBaseConnection)

Decrypt stream

procedure DecryptStream(const Stream: TStream)

Parameters:

  • Stream: Stream

Dispatch (IROMessage)  protected reintroduce overload    (declared in TROTransportChannel)

Sends a request message through the Self channel for processing and gets back an aMessage. CodeGen uses this method when generating a proxy from RODL Files.

procedure Dispatch(aMessage: IROMessage)

Parameters:

  • aMessage: (In/out) message data

DispatchOptions

Configures the available fail-over and load balancing options provided by the Remoting SDK. By default, channels are set up to talk to one specific server only. Two independent options are available to provide fail-over and load balancing:

  • Enables fail-over support. If the connection to any given server fails, the channel will automatically keep trying the next server specified in ServerLocators, until a working server is found or all servers have been tried.
  • Enables load-balancing support. Each request dispatched through the channel will go to a different server configured in ServerLocators, resulting in calls being more or less equally distributed over the available servers.

Enabling any of these options obviously requires the server to be implemented in a stateless way, so that it does not depend on all requests from a client going to the same server. This implies using a class factory different from Per-Client and, if sessions are used, a session manager that allows sharing of session state between servers.

property DispatchOptions: TRODispatchOptions read write

DLLHandle

The handle of the loaded server DLL, or 0 if no DLL is loaded.

property DLLHandle: THandle read

DLLLoaded

Indicates whether the server DLL is currently loaded.

property DLLLoaded: Boolean read

DLLName

Specifies the name of the DLL that contains the server. The name can be a fully qualified file name, or the name of a DLL in the processes search path.

property DLLName: string read write

DoAfterProbingServerEvent  protected virtual    (declared in TROTransportChannel)

Fires OnAfterProbingServer event

procedure DoAfterProbingServerEvent(const aServerLocator: TROServerLocator; const aFailed: Boolean)

Parameters:

  • aServerLocator: Server locator
  • aFailed:

DoAfterProbingServersEvent  protected virtual    (declared in TROTransportChannel)

Fires OnAfterProbingServer event

procedure DoAfterProbingServersEvent(const aProbedCount: Integer; const aEnabledCount: Integer; const aDisabledCount: Integer)

Parameters:

  • aProbedCount:
  • aEnabledCount:
  • aDisabledCount:

DoBeforeDecryptEvent  protected virtual    (declared in TROBaseConnection) obsolete

procedure DoBeforeDecryptEvent(aEncryptedStream: TStream)

Parameters:

  • aEncryptedStream: Stream

DoBeforeProbingServerEvent  protected virtual    (declared in TROTransportChannel)

Fires OnBeforeProbingServer event

procedure DoBeforeProbingServerEvent(const aServerLocator: TROServerLocator)

Parameters:

  • aServerLocator: Server locator

DoBeforeProbingServersEvent  protected virtual    (declared in TROTransportChannel)

Fires OnBeforeProbingServers event

procedure DoBeforeProbingServersEvent

DoNeedSSL  protected virtual    (declared in TROTransportChannel)

Detects SSL state

function DoNeedSSL: Boolean

DoReceiveStreamEvent  protected virtual    (declared in TROTransportChannel)

Fires OnSendStream event

procedure DoReceiveStreamEvent(const Dest: TStream)

Parameters:

  • Dest: Stream

DoSendStreamEvent  protected virtual    (declared in TROTransportChannel)

Fires OnSendStream event

procedure DoSendStreamEvent(const Source: TStream)

Parameters:

  • Source: Stream

DoServerLocatorAssignmentEvent  protected virtual    (declared in TROTransportChannel)

Fires OnServerLocatorAssignment event

procedure DoServerLocatorAssignmentEvent(const aLocator: TROServerLocator; const aException: Exception)

Parameters:

  • aLocator:
  • aException:

Encryption    (declared in TROBaseConnection) obsolete

This is DES based enscryption, it is obsolete because works only for Delphi. Use message envelope AES Encryption Envelope instead.

property Encryption: TROEncryption read write

EncryptStream (TStream, TStream)  protected overload    (declared in TROBaseConnection)

Encrypt stream

procedure EncryptStream(const Source: TStream; const Dest: TStream)

Parameters:

  • Source: Source
  • Dest: Destination

EncryptStream (TStream)  protected overload    (declared in TROBaseConnection)

Encrypt stream

procedure EncryptStream(const Stream: TStream)

Parameters:

  • Stream: Stream

EventReceiverList  protected    (declared in TROBaseActiveEventChannel)

Provides a list of registered IROEventReceiver

property EventReceiverList: TInterfaceList read

FaultToleranceLocatorIdx    (declared in TROTransportChannel)

property FaultToleranceLocatorIdx: Integer read write

GetBusy  protected virtual    (declared in TROTransportChannel)

Returns current channel state

function GetBusy: Boolean

GetChannelFromPool  protected virtual    (declared in TROTransportChannel)

function GetChannelFromPool: TROTransportChannel

GetTransportObject  protected virtual    (declared in TROTransportChannel)

Returns itself.

function GetTransportObject: TObject

InitServerLocator  protected virtual    (declared in TROTransportChannel)

Sets CurrentLocator

function InitServerLocator: Integer

IsEncryptionUsed  protected    (declared in TROBaseConnection)

Checks if encryption was used

function IsEncryptionUsed: Boolean

IsProbeMode  protected    (declared in TROTransportChannel)

property IsProbeMode: Boolean read

IsStreamEncrypted  protected    (declared in TROBaseConnection)

Checks state of stream

function IsStreamEncrypted(Source: TStream): Boolean

Parameters:

  • Source: Stream

KeepDLLLoaded

Determines whether the DLL should be kept in memory once it was loaded (true, default), or if it should be unloaded after each request (false). Set this property to false if you expect the DLL to be changed between requests.

property KeepDLLLoaded: Boolean read write

LaunchAsyncTask  protected    (declared in TROTransportChannel)

procedure LaunchAsyncTask(aRequest: IROAsyncRequest)

Parameters:

  • aRequest:

LoadBalancerLocatorIdx    (declared in TROTransportChannel)

property LoadBalancerLocatorIdx: Integer read write

LoadDLL  protected

procedure LoadDLL

LoadSSL  protected virtual    (declared in TROTransportChannel)

Loads SSL library if SSL protocol is used

procedure LoadSSL

Notification  protected override    (declared in TROBaseActiveEventChannel)

Forwards notification messages to all owned components.

procedure Notification(AComponent: TComponent; Operation: TOperation)

Parameters:

  • AComponent: component
  • Operation: operation

OnAfterEncrypt    (declared in TROBaseConnection)

Fired after stream was encrypted

property OnAfterEncrypt: TROBaseConnectionOperation read write
delegate: procedure OnAfterEncrypt(Sender: TROBaseConnection; aEncryptedStream: TStream)

OnAfterProbingServer    (declared in TROTransportChannel)

Fires after the channel is done probing a specific server for availability. You can use this event to check the result of the probing, possibly to update internal data structures or to display server status in the user interface.

property OnAfterProbingServer: TROEndProbeServerEvent read write
delegate: procedure OnAfterProbingServer(Sender: TROTransportChannel; aServerLocator: TROServerLocator; Failed: Boolean)

OnAfterProbingServers    (declared in TROTransportChannel)

Fires after the channel is done probing all servers for availability. You can use this event to check the result of the probing, possibly to update internal data structures or to display server status in the user interface.

property OnAfterProbingServers: TROEndProbeServersEvent read write
delegate: procedure OnAfterProbingServers(Sender: TROTransportChannel; ProbedCount: Integer; EnabledCount: Integer; DisabledCount: Integer)

OnAsyncException    (declared in TROTransportChannel)

Fires when exception is raised in asynchronous mode

property OnAsyncException: TROAsyncExceptionEvent read write
delegate: procedure OnAsyncException(Sender: TROTransportChannel; Async: IROAsyncInterface; anException: Exception)

OnBeforeDecrypt    (declared in TROBaseConnection)

Fired before stream will be decrypted

property OnBeforeDecrypt: TROBaseConnectionOperation read write
delegate: procedure OnBeforeDecrypt(Sender: TROBaseConnection; aEncryptedStream: TStream)

OnBeforeProbingServer    (declared in TROTransportChannel)

Fires before the channel starts probing a specific server for availability. You can use this event to:

property OnBeforeProbingServer: TROBeginProbeServerEvent read write
delegate: procedure OnBeforeProbingServer(Sender: TROTransportChannel; aServerLocator: TROServerLocator)

OnBeforeProbingServers    (declared in TROTransportChannel)

Fires before the channel starts probing all servers for availability. You can use this event:

  • to check or adjust the server configurations
  • to include/exclude individual server from being probed by changing their TROServerLocator properties.
property OnBeforeProbingServers: TROBeginProbeServersEvent read write
delegate: procedure OnBeforeProbingServers(Sender: TROTransportChannel)

OnDLLLoaded

Fires after the server DLL has been successfully loaded.

property OnDLLLoaded: TDLLLoadEvent read write
delegate: procedure OnDLLLoaded(Sender: TObject; DLLHandle: THandle)

OnDLLUnloaded

Fires after the server DLL has been successfully unloaded.

property OnDLLUnloaded: TDLLUnloadEvent read write

OnException    (declared in TROTransportChannel)

Fires if an exception is raised during the execution of a remote request. This could be an exception returned from the server, a communication problem or an error within the client. Depending on the type of error, your event handler can try to rectify the problem, and set aRetry to true to have the channel try and perform the request again. For example, an application could show a dialog asking the user to confirm if his internet connection is available, with Cancel and Retry buttons.
If aRetry is set to true and the call succeeds at the second attempt, the call will return to the original code that initiated the request, as if the exception never happened.

property OnException: TROExceptionEvent read write
delegate: procedure OnException(Sender: TROTransportChannel; anException: Exception; var aRetry: Boolean)

OnLoginNeeded    (declared in TROTransportChannel)

Fires if an EROSessionNotFound (or the descendant SessionNotFoundException) exception is raised during the execution of a remote request. This usually indicates that the server cannot authenticate the client or that the session has expired. The most common use for this event is to perform a call to a special Login service provided by the server (possibly after prompting the user to enter username and password), and to set the aRetry parameter to true if login was successful.

property OnLoginNeeded: TROExceptionEvent read write
delegate: procedure OnLoginNeeded(Sender: TROTransportChannel; anException: Exception; var aRetry: Boolean)

OnProgress    (declared in TROTransportChannel)

This event fires as the channel is transferring data for a request or response to or from the server, informing of the current progress. It can be used to keep the user interface updated during lengthy transfers,e.g. by showing a progress bar or the remaining transfer volume. Note: the accuracy and frequency of calls to OnProgress depends on the channel type; since channels transport data packets in different sized chunks (or even all-at-once), OnProgress might show a very fine progress for some channels, while jumping from 0 to 100% in one step with others.

property OnProgress: TProgressEvent read write
delegate: procedure OnProgress(aSender: TObject; aType: TProgressType; aDirection: TProgressDirection; aTransferred: Integer; aTotal: Integer)

OnReceiveStream    (declared in TROTransportChannel)

Fires after a stream with a response message has been received from the server. Use this event handler to inspect and possibly modify the stream, before it continues to be processed by the higher levels of the Remoting SDK framework.

property OnReceiveStream: TStreamDispatch read write
delegate: procedure OnReceiveStream(aStream: TStream)

OnSendStream    (declared in TROTransportChannel)

Fires just as a stream with a request message will be sent to the server. The event handler can inspect and possibly modify the stream, before it continues to be sent off to the server.

property OnSendStream: TStreamDispatch read write
delegate: procedure OnSendStream(aStream: TStream)

OnServerLocatorAssignment    (declared in TROTransportChannel)

Fires before changing of a server locator.

property OnServerLocatorAssignment: TServerLocatorAssignment read write
delegate: procedure OnServerLocatorAssignment(Sender: TROTransportChannel; aLocator: TROServerLocator; aException: Exception)

Probe  protected    (declared in TROTransportChannel)

Checks the accessibility of servers from the ServerLocators. This method is intended to provide fail-over and load balancing support in the Remoting SDK Architecture.

function Probe(aServerLocator: TROServerLocator): Boolean

Parameters:

  • aServerLocator: Server locator

ProbeAll  protected    (declared in TROTransportChannel)

Checks the availability of all known servers.

procedure ProbeAll

ProbeFrequency    (declared in TROTransportChannel)

Sets at what intervals, in milliseconds, the channel will probe the servers configured in ServerLocators for availability. The default value is 60,000 (60 seconds). See the ProbeServers property for a more detailed description. Although somewhat misnamed, this property defines the Interval between probes, not the actual probing Frequency. The property name is persisted for backward compatibility.

property ProbeFrequency: Cardinal read write

ProbeServers    (declared in TROTransportChannel)

Toggles whether the channel will continuously probe the servers configured in ServerLocators for availability. If enabled (true), the channel will ping all servers at a regular interval to determine if they are reachable. If a server fails to respond, it will be disabled for future calls until a later probe can reach it again. The interval between probes can be configured using the ProbeFrequency property. By default, server probing is turned off.

property ProbeServers: Boolean read write

ProcessEvent  protected

Receives an event from the TRODLLServer.

procedure ProcessEvent(Data: Pointer; DataSize: Integer)

Parameters:

  • Data: Points to the buffer where the data is stored.
  • DataSize: Indicates the size of the data in the buffer.

RegisterEventReceiver  protected override

Registers a new event receiver object aReceiver in the specified channel. This procedure is needed to further use the aReceiver as receiver for callback events.

procedure RegisterEventReceiver(aReceiver: IROEventReceiver)

Parameters:

  • aReceiver: the event receiver that should be registered.

ResetProbingClone  protected virtual    (declared in TROTransportChannel)

Resets channel that is used for probing

procedure ResetProbingClone(aProbe: TROTransportChannel)

Parameters:

  • aProbe: Probing clone

RetrieveMetadata  protected virtual    (declared in TROTransportChannel)

Returns server-side RODL.

procedure RetrieveMetadata(out Dest: TStream)

Parameters:

  • Dest: Stream

RetrieveRODL  protected    (declared in TROTransportChannel)

This method is used for to obtaining the RODL library from the server without havin to rely on a channel-specific mechanism (such as a HTTP request to http://servername:port/rodl).

procedure RetrieveRODL(out RODLLibrary: TRODLLibrary)

Parameters:

  • RODLLibrary: Result

ReturnChannelToPool  protected virtual    (declared in TROTransportChannel)

procedure ReturnChannelToPool(aChannel: TROTransportChannel)

Parameters:

  • aChannel:

ROFreeNotification    (declared in TROComponent)

Forwards notification messages to all owned components.

procedure ROFreeNotification(aComponent: TComponent)

Parameters:

  • aComponent: component

RORemoveFreeNotification    (declared in TROComponent)

Forwards notification messages to all owned components.

procedure RORemoveFreeNotification(aComponent: TComponent)

Parameters:

  • aComponent: component

SendRemoveNotification  protected    (declared in TROComponent)

Forwards notification messages to all owned components.

procedure SendRemoveNotification(aComponent: TComponent)

Parameters:

  • aComponent: component

ServerLocators

Optionally, this collection property can be filled to contain a list of possible servers to be used for fail-over or load balancing purposes. Depending on the settings configured in DispatchOptions, the channel will automatically spread calls over the available servers, or fall back to another server if one fails.

property ServerLocators: TROServerLocatorCollection read write

SetAsyncBusy  protected virtual    (declared in TROTransportChannel)

procedure SetAsyncBusy(const Value: Boolean)

Parameters:

  • Value:

SetServerLocator  protected    (declared in TROTransportChannel)

Retrieves the location details of a server from aServerLocator.

procedure SetServerLocator(aServerLocator: TROServerLocator; anException: Exception)

Parameters:

  • aServerLocator: Configuration data of the server
  • anException: Exception

SupportsActiveEvents

Returns false if active events aren't supported by the server

property SupportsActiveEvents: Boolean read

SynchronizedProbing    (declared in TROTransportChannel)

Determines whether server probing happens in the context of the main VCL thread (true, default) or in a background worker thread. See the ProbeServers property for a more detailed description.

property SynchronizedProbing: Boolean read write

TargetUri    (declared in TROTransportChannel)

Target URI

property TargetUri: TROUri read write

TargetUrl  protected    (declared in TROTransportChannel)

The address of the server.

property TargetUrl: string read write

ThreadSafe  protected    (declared in TROTransportChannel)

property ThreadSafe: Boolean read write

TriggerProgress  protected virtual    (declared in TROTransportChannel)

Fires OnProgress event

procedure TriggerProgress(aType: TProgressType; aDirection: TProgressDirection; aTransfered: Integer; aTotal: Integer)

Parameters:

  • aType: progress type
  • aDirection: direction
  • aTransfered: transfered bytes
  • aTotal: total bytes

UnloadDLL

Forces an unload of the DLL. Call this method manually if you need to change or update the DLL before the next call, or if you need to have it unloaded from the process.

procedure UnloadDLL

UnregisterEventReceiver  protected override

Unregisters the specified IROEventReceiver aReceiver in the specified channel.

procedure UnregisterEventReceiver(aReceiver: IROEventReceiver)

Parameters:

  • aReceiver: The event receiver that should be unregistered.

UnregisterEventReceivers  protected    (declared in TROBaseActiveEventChannel)

Unregisters the all event receivers in the specified channel.

procedure UnregisterEventReceivers

 

ActiveClientID

property ActiveClientID: TGUID read write

ActiveEvents

Allows to support IROActiveEventChannel

property ActiveEvents: Boolean read write

Busy    (declared in TROTransportChannel)

Informs whether the channel is currently busy executing a remote request (true) or not (false). Most channels (except most notably the TROSuperTCPChannel) are only capable of performing one request at a time; if a second request is attempted while the channel is Busy, an EROChannelBusy exception will be raised.

property Busy: Boolean read

ClientId

Contains the Client ID.

property ClientId: TGUID read write

CurrentLocator    (declared in TROTransportChannel)

Returns which of the fail-over/load balancing servers configured in the ServerLocators is currently active. Depending on the DispatchOptions defined, this value might change with each request, or only if the current server fails.

property CurrentLocator: TROServerLocator read write

DispatchOptions

Configures the available fail-over and load balancing options provided by the Remoting SDK. By default, channels are set up to talk to one specific server only. Two independent options are available to provide fail-over and load balancing:

  • Enables fail-over support. If the connection to any given server fails, the channel will automatically keep trying the next server specified in ServerLocators, until a working server is found or all servers have been tried.
  • Enables load-balancing support. Each request dispatched through the channel will go to a different server configured in ServerLocators, resulting in calls being more or less equally distributed over the available servers.

Enabling any of these options obviously requires the server to be implemented in a stateless way, so that it does not depend on all requests from a client going to the same server. This implies using a class factory different from Per-Client and, if sessions are used, a session manager that allows sharing of session state between servers.

property DispatchOptions: TRODispatchOptions read write

DLLHandle

The handle of the loaded server DLL, or 0 if no DLL is loaded.

property DLLHandle: THandle read

DLLLoaded

Indicates whether the server DLL is currently loaded.

property DLLLoaded: Boolean read

DLLName

Specifies the name of the DLL that contains the server. The name can be a fully qualified file name, or the name of a DLL in the processes search path.

property DLLName: string read write

Encryption    (declared in TROBaseConnection) obsolete

This is DES based enscryption, it is obsolete because works only for Delphi. Use message envelope AES Encryption Envelope instead.

property Encryption: TROEncryption read write

EventReceiverList  protected    (declared in TROBaseActiveEventChannel)

Provides a list of registered IROEventReceiver

property EventReceiverList: TInterfaceList read

FaultToleranceLocatorIdx    (declared in TROTransportChannel)

property FaultToleranceLocatorIdx: Integer read write

IsProbeMode  protected    (declared in TROTransportChannel)

property IsProbeMode: Boolean read

KeepDLLLoaded

Determines whether the DLL should be kept in memory once it was loaded (true, default), or if it should be unloaded after each request (false). Set this property to false if you expect the DLL to be changed between requests.

property KeepDLLLoaded: Boolean read write

LoadBalancerLocatorIdx    (declared in TROTransportChannel)

property LoadBalancerLocatorIdx: Integer read write

ProbeFrequency    (declared in TROTransportChannel)

Sets at what intervals, in milliseconds, the channel will probe the servers configured in ServerLocators for availability. The default value is 60,000 (60 seconds). See the ProbeServers property for a more detailed description. Although somewhat misnamed, this property defines the Interval between probes, not the actual probing Frequency. The property name is persisted for backward compatibility.

property ProbeFrequency: Cardinal read write

ProbeServers    (declared in TROTransportChannel)

Toggles whether the channel will continuously probe the servers configured in ServerLocators for availability. If enabled (true), the channel will ping all servers at a regular interval to determine if they are reachable. If a server fails to respond, it will be disabled for future calls until a later probe can reach it again. The interval between probes can be configured using the ProbeFrequency property. By default, server probing is turned off.

property ProbeServers: Boolean read write

ServerLocators

Optionally, this collection property can be filled to contain a list of possible servers to be used for fail-over or load balancing purposes. Depending on the settings configured in DispatchOptions, the channel will automatically spread calls over the available servers, or fall back to another server if one fails.

property ServerLocators: TROServerLocatorCollection read write

SupportsActiveEvents

Returns false if active events aren't supported by the server

property SupportsActiveEvents: Boolean read

SynchronizedProbing    (declared in TROTransportChannel)

Determines whether server probing happens in the context of the main VCL thread (true, default) or in a background worker thread. See the ProbeServers property for a more detailed description.

property SynchronizedProbing: Boolean read write

TargetUri    (declared in TROTransportChannel)

Target URI

property TargetUri: TROUri read write

TargetUrl  protected    (declared in TROTransportChannel)

The address of the server.

property TargetUrl: string read write

ThreadSafe  protected    (declared in TROTransportChannel)

property ThreadSafe: Boolean read write

 

ChannelMatchingTargetUri    (declared in TROTransportChannel)

Creates a client channel instance with type, target host and target port matching the provided target Uri.
F.e. for provided uri supertcp://192.168.1.100:7020/bin this method will return an instance of the Super Tcp channel with target host set to 192.168.1.100 and port set to 7020.

class function ChannelMatchingTargetUri(const aUri: TROUri): TROTransportChannel

Parameters:

  • aUri: Server Uri

ChannelMatchingTargetUrl    (declared in TROTransportChannel)

class function ChannelMatchingTargetUrl(const aUrl: string): TROTransportChannel

Parameters:

  • aUrl:

 

constructor Create  override

Standard component constructor

constructor Create(aOwner: TComponent)

Parameters:

  • aOwner: Owner

Assign  override    (declared in TROTransportChannel)

Copies the contents of another, similar object.

procedure Assign(Source: TPersistent)

Parameters:

  • Source: Instance whose properties will be copied

AssignEvents  protected override

Copies the events of another, similar object.

procedure AssignEvents(aSource: TROTransportChannel)

Parameters:

  • aSource: Instance whose properties will be copied

AssignSpecificProperties  protected override

Copies the specific properties of another, similar object.

procedure AssignSpecificProperties(aSource: TROTransportChannel)

Parameters:

  • aSource: Instance whose properties will be copied

AsyncException  protected virtual    (declared in TROTransportChannel)

Notifies about an exception in an asynchronous mode.

procedure AsyncException(aAsyncInterface: IROAsyncInterface; AsyncException: Exception)

Parameters:

  • aAsyncInterface: Exception source
  • AsyncException: Exception data

BeforeDispatch  protected override

Allows an implimentation to do necessary preparatory actions (checking the readiness of the channel, restore session data, etc.).

procedure BeforeDispatch(aMessage: IROMessage)

Parameters:


CallbackEvents  protected    (declared in TROBaseActiveEventChannel)

Sends event to each registered IROEventReceiver

procedure CallbackEvents(aData: TStream; aThread: TThread)

Parameters:

  • aData: Data stream
  • aThread: Working thread to process the event

ChangeServerLocator  protected virtual    (declared in TROTransportChannel)

procedure ChangeServerLocator(var aFaultStartLocatorIdx: Integer; var aRetry: Boolean; const aException: Exception)

Parameters:

  • aFaultStartLocatorIdx:
  • aRetry:
  • aException:

CheckProperties  override

Validates channel properties

procedure CheckProperties

DecryptStream (TStream, TStream)  protected overload    (declared in TROBaseConnection)

Decrypt stream

procedure DecryptStream(const Source: TStream; const Dest: TStream)

Parameters:

  • Source: Source
  • Dest: Destination

DecryptStream (TStream)  protected overload    (declared in TROBaseConnection)

Decrypt stream

procedure DecryptStream(const Stream: TStream)

Parameters:

  • Stream: Stream

Dispatch (IROMessage)  protected reintroduce overload    (declared in TROTransportChannel)

Sends a request message through the Self channel for processing and gets back an aMessage. CodeGen uses this method when generating a proxy from RODL Files.

procedure Dispatch(aMessage: IROMessage)

Parameters:

  • aMessage: (In/out) message data

DoAfterProbingServerEvent  protected virtual    (declared in TROTransportChannel)

Fires OnAfterProbingServer event

procedure DoAfterProbingServerEvent(const aServerLocator: TROServerLocator; const aFailed: Boolean)

Parameters:

  • aServerLocator: Server locator
  • aFailed:

DoAfterProbingServersEvent  protected virtual    (declared in TROTransportChannel)

Fires OnAfterProbingServer event

procedure DoAfterProbingServersEvent(const aProbedCount: Integer; const aEnabledCount: Integer; const aDisabledCount: Integer)

Parameters:

  • aProbedCount:
  • aEnabledCount:
  • aDisabledCount:

DoBeforeDecryptEvent  protected virtual    (declared in TROBaseConnection) obsolete

procedure DoBeforeDecryptEvent(aEncryptedStream: TStream)

Parameters:

  • aEncryptedStream: Stream

DoBeforeProbingServerEvent  protected virtual    (declared in TROTransportChannel)

Fires OnBeforeProbingServer event

procedure DoBeforeProbingServerEvent(const aServerLocator: TROServerLocator)

Parameters:

  • aServerLocator: Server locator

DoBeforeProbingServersEvent  protected virtual    (declared in TROTransportChannel)

Fires OnBeforeProbingServers event

procedure DoBeforeProbingServersEvent

DoNeedSSL  protected virtual    (declared in TROTransportChannel)

Detects SSL state

function DoNeedSSL: Boolean

DoReceiveStreamEvent  protected virtual    (declared in TROTransportChannel)

Fires OnSendStream event

procedure DoReceiveStreamEvent(const Dest: TStream)

Parameters:

  • Dest: Stream

DoSendStreamEvent  protected virtual    (declared in TROTransportChannel)

Fires OnSendStream event

procedure DoSendStreamEvent(const Source: TStream)

Parameters:

  • Source: Stream

DoServerLocatorAssignmentEvent  protected virtual    (declared in TROTransportChannel)

Fires OnServerLocatorAssignment event

procedure DoServerLocatorAssignmentEvent(const aLocator: TROServerLocator; const aException: Exception)

Parameters:

  • aLocator:
  • aException:

EncryptStream (TStream, TStream)  protected overload    (declared in TROBaseConnection)

Encrypt stream

procedure EncryptStream(const Source: TStream; const Dest: TStream)

Parameters:

  • Source: Source
  • Dest: Destination

EncryptStream (TStream)  protected overload    (declared in TROBaseConnection)

Encrypt stream

procedure EncryptStream(const Stream: TStream)

Parameters:

  • Stream: Stream

GetBusy  protected virtual    (declared in TROTransportChannel)

Returns current channel state

function GetBusy: Boolean

GetChannelFromPool  protected virtual    (declared in TROTransportChannel)

function GetChannelFromPool: TROTransportChannel

GetTransportObject  protected virtual    (declared in TROTransportChannel)

Returns itself.

function GetTransportObject: TObject

InitServerLocator  protected virtual    (declared in TROTransportChannel)

Sets CurrentLocator

function InitServerLocator: Integer

IsEncryptionUsed  protected    (declared in TROBaseConnection)

Checks if encryption was used

function IsEncryptionUsed: Boolean

IsStreamEncrypted  protected    (declared in TROBaseConnection)

Checks state of stream

function IsStreamEncrypted(Source: TStream): Boolean

Parameters:

  • Source: Stream

LaunchAsyncTask  protected    (declared in TROTransportChannel)

procedure LaunchAsyncTask(aRequest: IROAsyncRequest)

Parameters:

  • aRequest:

LoadDLL  protected

procedure LoadDLL

LoadSSL  protected virtual    (declared in TROTransportChannel)

Loads SSL library if SSL protocol is used

procedure LoadSSL

Notification  protected override    (declared in TROBaseActiveEventChannel)

Forwards notification messages to all owned components.

procedure Notification(AComponent: TComponent; Operation: TOperation)

Parameters:

  • AComponent: component
  • Operation: operation

Probe  protected    (declared in TROTransportChannel)

Checks the accessibility of servers from the ServerLocators. This method is intended to provide fail-over and load balancing support in the Remoting SDK Architecture.

function Probe(aServerLocator: TROServerLocator): Boolean

Parameters:

  • aServerLocator: Server locator

ProbeAll  protected    (declared in TROTransportChannel)

Checks the availability of all known servers.

procedure ProbeAll

ProcessEvent  protected

Receives an event from the TRODLLServer.

procedure ProcessEvent(Data: Pointer; DataSize: Integer)

Parameters:

  • Data: Points to the buffer where the data is stored.
  • DataSize: Indicates the size of the data in the buffer.

RegisterEventReceiver  protected override

Registers a new event receiver object aReceiver in the specified channel. This procedure is needed to further use the aReceiver as receiver for callback events.

procedure RegisterEventReceiver(aReceiver: IROEventReceiver)

Parameters:

  • aReceiver: the event receiver that should be registered.

ResetProbingClone  protected virtual    (declared in TROTransportChannel)

Resets channel that is used for probing

procedure ResetProbingClone(aProbe: TROTransportChannel)

Parameters:

  • aProbe: Probing clone

RetrieveMetadata  protected virtual    (declared in TROTransportChannel)

Returns server-side RODL.

procedure RetrieveMetadata(out Dest: TStream)

Parameters:

  • Dest: Stream

RetrieveRODL  protected    (declared in TROTransportChannel)

This method is used for to obtaining the RODL library from the server without havin to rely on a channel-specific mechanism (such as a HTTP request to http://servername:port/rodl).

procedure RetrieveRODL(out RODLLibrary: TRODLLibrary)

Parameters:

  • RODLLibrary: Result

ReturnChannelToPool  protected virtual    (declared in TROTransportChannel)

procedure ReturnChannelToPool(aChannel: TROTransportChannel)

Parameters:

  • aChannel:

ROFreeNotification    (declared in TROComponent)

Forwards notification messages to all owned components.

procedure ROFreeNotification(aComponent: TComponent)

Parameters:

  • aComponent: component

RORemoveFreeNotification    (declared in TROComponent)

Forwards notification messages to all owned components.

procedure RORemoveFreeNotification(aComponent: TComponent)

Parameters:

  • aComponent: component

SendRemoveNotification  protected    (declared in TROComponent)

Forwards notification messages to all owned components.

procedure SendRemoveNotification(aComponent: TComponent)

Parameters:

  • aComponent: component

SetAsyncBusy  protected virtual    (declared in TROTransportChannel)

procedure SetAsyncBusy(const Value: Boolean)

Parameters:

  • Value:

SetServerLocator  protected    (declared in TROTransportChannel)

Retrieves the location details of a server from aServerLocator.

procedure SetServerLocator(aServerLocator: TROServerLocator; anException: Exception)

Parameters:

  • aServerLocator: Configuration data of the server
  • anException: Exception

TriggerProgress  protected virtual    (declared in TROTransportChannel)

Fires OnProgress event

procedure TriggerProgress(aType: TProgressType; aDirection: TProgressDirection; aTransfered: Integer; aTotal: Integer)

Parameters:

  • aType: progress type
  • aDirection: direction
  • aTransfered: transfered bytes
  • aTotal: total bytes

UnloadDLL

Forces an unload of the DLL. Call this method manually if you need to change or update the DLL before the next call, or if you need to have it unloaded from the process.

procedure UnloadDLL

UnregisterEventReceiver  protected override

Unregisters the specified IROEventReceiver aReceiver in the specified channel.

procedure UnregisterEventReceiver(aReceiver: IROEventReceiver)

Parameters:

  • aReceiver: The event receiver that should be unregistered.

UnregisterEventReceivers  protected    (declared in TROBaseActiveEventChannel)

Unregisters the all event receivers in the specified channel.

procedure UnregisterEventReceivers

 

OnAfterEncrypt    (declared in TROBaseConnection)

Fired after stream was encrypted

property OnAfterEncrypt: TROBaseConnectionOperation read write
delegate: procedure OnAfterEncrypt(Sender: TROBaseConnection; aEncryptedStream: TStream)

OnAfterProbingServer    (declared in TROTransportChannel)

Fires after the channel is done probing a specific server for availability. You can use this event to check the result of the probing, possibly to update internal data structures or to display server status in the user interface.

property OnAfterProbingServer: TROEndProbeServerEvent read write
delegate: procedure OnAfterProbingServer(Sender: TROTransportChannel; aServerLocator: TROServerLocator; Failed: Boolean)

OnAfterProbingServers    (declared in TROTransportChannel)

Fires after the channel is done probing all servers for availability. You can use this event to check the result of the probing, possibly to update internal data structures or to display server status in the user interface.

property OnAfterProbingServers: TROEndProbeServersEvent read write
delegate: procedure OnAfterProbingServers(Sender: TROTransportChannel; ProbedCount: Integer; EnabledCount: Integer; DisabledCount: Integer)

OnAsyncException    (declared in TROTransportChannel)

Fires when exception is raised in asynchronous mode

property OnAsyncException: TROAsyncExceptionEvent read write
delegate: procedure OnAsyncException(Sender: TROTransportChannel; Async: IROAsyncInterface; anException: Exception)

OnBeforeDecrypt    (declared in TROBaseConnection)

Fired before stream will be decrypted

property OnBeforeDecrypt: TROBaseConnectionOperation read write
delegate: procedure OnBeforeDecrypt(Sender: TROBaseConnection; aEncryptedStream: TStream)

OnBeforeProbingServer    (declared in TROTransportChannel)

Fires before the channel starts probing a specific server for availability. You can use this event to:

property OnBeforeProbingServer: TROBeginProbeServerEvent read write
delegate: procedure OnBeforeProbingServer(Sender: TROTransportChannel; aServerLocator: TROServerLocator)

OnBeforeProbingServers    (declared in TROTransportChannel)

Fires before the channel starts probing all servers for availability. You can use this event:

  • to check or adjust the server configurations
  • to include/exclude individual server from being probed by changing their TROServerLocator properties.
property OnBeforeProbingServers: TROBeginProbeServersEvent read write
delegate: procedure OnBeforeProbingServers(Sender: TROTransportChannel)

OnDLLLoaded

Fires after the server DLL has been successfully loaded.

property OnDLLLoaded: TDLLLoadEvent read write
delegate: procedure OnDLLLoaded(Sender: TObject; DLLHandle: THandle)

OnDLLUnloaded

Fires after the server DLL has been successfully unloaded.

property OnDLLUnloaded: TDLLUnloadEvent read write

OnException    (declared in TROTransportChannel)

Fires if an exception is raised during the execution of a remote request. This could be an exception returned from the server, a communication problem or an error within the client. Depending on the type of error, your event handler can try to rectify the problem, and set aRetry to true to have the channel try and perform the request again. For example, an application could show a dialog asking the user to confirm if his internet connection is available, with Cancel and Retry buttons.
If aRetry is set to true and the call succeeds at the second attempt, the call will return to the original code that initiated the request, as if the exception never happened.

property OnException: TROExceptionEvent read write
delegate: procedure OnException(Sender: TROTransportChannel; anException: Exception; var aRetry: Boolean)

OnLoginNeeded    (declared in TROTransportChannel)

Fires if an EROSessionNotFound (or the descendant SessionNotFoundException) exception is raised during the execution of a remote request. This usually indicates that the server cannot authenticate the client or that the session has expired. The most common use for this event is to perform a call to a special Login service provided by the server (possibly after prompting the user to enter username and password), and to set the aRetry parameter to true if login was successful.

property OnLoginNeeded: TROExceptionEvent read write
delegate: procedure OnLoginNeeded(Sender: TROTransportChannel; anException: Exception; var aRetry: Boolean)

OnProgress    (declared in TROTransportChannel)

This event fires as the channel is transferring data for a request or response to or from the server, informing of the current progress. It can be used to keep the user interface updated during lengthy transfers,e.g. by showing a progress bar or the remaining transfer volume. Note: the accuracy and frequency of calls to OnProgress depends on the channel type; since channels transport data packets in different sized chunks (or even all-at-once), OnProgress might show a very fine progress for some channels, while jumping from 0 to 100% in one step with others.

property OnProgress: TProgressEvent read write
delegate: procedure OnProgress(aSender: TObject; aType: TProgressType; aDirection: TProgressDirection; aTransferred: Integer; aTotal: Integer)

OnReceiveStream    (declared in TROTransportChannel)

Fires after a stream with a response message has been received from the server. Use this event handler to inspect and possibly modify the stream, before it continues to be processed by the higher levels of the Remoting SDK framework.

property OnReceiveStream: TStreamDispatch read write
delegate: procedure OnReceiveStream(aStream: TStream)

OnSendStream    (declared in TROTransportChannel)

Fires just as a stream with a request message will be sent to the server. The event handler can inspect and possibly modify the stream, before it continues to be sent off to the server.

property OnSendStream: TStreamDispatch read write
delegate: procedure OnSendStream(aStream: TStream)

OnServerLocatorAssignment    (declared in TROTransportChannel)

Fires before changing of a server locator.

property OnServerLocatorAssignment: TServerLocatorAssignment read write
delegate: procedure OnServerLocatorAssignment(Sender: TROTransportChannel; aLocator: TROServerLocator; aException: Exception)