TROSynapseSuperHTTPChannel

 

Standard component constructor

constructor Create(aOwner: TComponent)

Parameters:

• aOwner: Owner

---

Allows to get channel's activity state, whether the channel active i.e. attempts to connect or already connected. Allows to activate and deactivate the channel.

property Active: Boolean read write

---

Allows to use GZIP compression

property AllowGzipEncoding: Boolean read write

---

Copies the contents of another, similar object.

procedure Assign(Source: TPersistent)

Parameters:

• Source: Instance whose properties will be copied

---

Copies the events of another, similar object.

procedure AssignEvents(aSource: TROTransportChannel)

Parameters:

• aSource: Instance whose properties will be copied

---

Copies the specific properties of another, similar object.

procedure AssignSpecificProperties(aSource: TROTransportChannel)

Parameters:

• aSource: Instance whose properties will be copied

---

Notifies about an exception in an asynchronous mode.

procedure AsyncException(aAsyncInterface: IROAsyncInterface; AsyncException: Exception)

Parameters:

• aAsyncInterface: Exception source
• AsyncException: Exception data

---

Specifies whether to use auto reconnect feature if the specified server is not available.

property AutoReconnect: Boolean read write

---

Controls the auto-reconnect behavior, if enabled. For possible auto-reconnect modes see TROSCAutoReconnectBehavior enum.

property AutoReconnectBehavior: TROSCAutoReconnectBehavior read write

---

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

procedure BeforeDispatch(aMessage: IROMessage)

Parameters:

• aMessage: Message

---

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

---

Calculates size of incoming package.

function CalcRequestStreamSize(const aData: TStream): Integer

Parameters:

• aData: Incoming package

---

Sends event to each registered IROEventReceiver

procedure CallbackEvents(aData: TStream; aThread: TThread)

Parameters:

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

---

Cancels the specified request to stop the threads when overridden.

procedure CancelRequest(aWaitingThread: Boolean)

Parameters:

• aWaitingThread: Specified waiting thread that should be stopped

---

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

Parameters:

• aFaultStartLocatorIdx:
• aRetry:
• aException:

---

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

---

class function ChannelMatchingTargetUrl(const aUrl: string): TROTransportChannel

Parameters:

• aUrl:

---

Validates channel properties

procedure CheckProperties

---

Indicates whether an answer is received after an InvokeRequest.

function CheckStatus(const aMessageID: string): Boolean

Parameters:

• aMessageID: Value of the previously called InvokeRequest result

---

The unique identifier of the client and it's session on the server. See TROMessage description for more details. The property is assigned automatically during the process of data exchange between the client and the server.

property ClientId: TGUID read write

---

Provides direct access to the underlying Synapse implementation. You can use this property to control advanced settings on the Synapse object.

property ClientRequest: THTTPSend read

---

Provides direct access to the underlying Synapse implementation. You can use this property to control advanced settings on the Synapse object.

property ClientWait: THTTPSend read

---

Returns true if the channel is connected to the server.

property Connected: Boolean read

---

property ConnectEvent: TROEvent read

---

Identifies a connection to this client on the server. Note that the value of this property does not necessarily correspond with the session ID on the server side.

property ConnectionId: TGUID read write

---

The timeout to establish connection to the server. Expressed in milliseconds, the default value is 10000 (10 sec).

property ConnectionWaitTimeout: Integer read write

---

Connection timeout

property ConnectTimeout: Integer read write

---

function CreateWorkerThread: TThread

---

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

---

Decrypt stream

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

Parameters:

• Source: Source
• Dest: Destination

---

Decrypt stream

procedure DecryptStream(const Stream: TStream)

Parameters:

• Stream: Stream

---

Controls whether data packets are sent individually or if small packets are held back to send as part of fewer larger data packets. Normally, you will want this disabled as it can have a significant effect on performance. The only time when its worth keeping the property enabled is when there are many small packets to be sent and you need to keep network bandwidth to a minimum.

See more at Nagle's algorithm

property DisableNagle: Boolean read write

---

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

---

Dispatches the HTTP request to the server and gets the response when overridden.

procedure DispatchHTTPRequest(aWaitingThread: Boolean; aRequest: TStream; out aResponse: TStream)

Parameters:

• aWaitingThread: If true, this parameter uses the HTTP client for the waiting thread instead of the requesting thread
• aRequest: Request body
• aResponse: Response data

---

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

---

Fires OnAfterProbingServer event

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

Parameters:

• aServerLocator: Server locator
• aFailed:

---

Fires OnAfterProbingServer event

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

Parameters:

• aProbedCount:
• aEnabledCount:
• aDisabledCount:

---

procedure DoBeforeDecryptEvent(aEncryptedStream: TStream)

Parameters:

• aEncryptedStream: Stream

---

Fires OnBeforeProbingServer event

procedure DoBeforeProbingServerEvent(const aServerLocator: TROServerLocator)

Parameters:

• aServerLocator: Server locator

---

Fires OnBeforeProbingServers event

procedure DoBeforeProbingServersEvent

---

Performs GZIP decoding

procedure DoDecodeStream(const aSource: TStream; const aDest: TStream)

Parameters:

• aSource: Source
• aDest: Destination

---

Performs GZIP encoding

procedure DoEncodeStream(const aSource: TStream)

Parameters:

• aSource: Source

---

Calls OnInvalidClientID event

procedure DoInvalidClientIDEvent(var aReconnect: Boolean)

Parameters:

• aReconnect: Allows reconnect

---

Detects SSL state

function DoNeedSSL: Boolean

---

function DoProcessError(const aId: Integer; const aErrorNo: Integer): Boolean

Parameters:

• aId:
• aErrorNo:

---

Fires OnSendStream event

procedure DoReceiveStreamEvent(const Dest: TStream)

Parameters:

• Dest: Stream

---

procedure DoReconnect(var aRestartLoop: Boolean)

Parameters:

• aRestartLoop:

---

Fires OnSendStream event

procedure DoSendStreamEvent(const Source: TStream)

Parameters:

• Source: Stream

---

Fires OnServerLocatorAssignment event

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

Parameters:

• aLocator:
• aException:

---

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

---

Encrypt stream

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

Parameters:

• Source: Source
• Dest: Destination

---

Encrypt stream

procedure EncryptStream(const Stream: TStream)

Parameters:

• Stream: Stream

---

Provides a list of registered IROEventReceiver

property EventReceiverList: TInterfaceList read

---

Refers to the TROThreadPool instance to provide a thread pool to execute event handling routines on. If the thread pool is not set explicitly it is created autromatically upon access.

property EventThreadPool: TROThreadPool read write

---

property FaultToleranceLocatorIdx: Integer read write

---

function FindWaitingRequest(aList: TList<TROWaitingRequest>; aId: Integer): TROWaitingRequest

Parameters:

• aList:
• aId:

---

Returns current channel state

function GetBusy: Boolean

---

Gets CanUseContentEncoding value.

function GetCanUseContentEncoding: Boolean

---

function GetChannelFromPool: TROTransportChannel

---

Returns the host URL with the prefix 'http' when overridden.

function GetLocation: string

---

Returns the virtual path to the specified service when overridden.

function GetPathInfo: string

---

Returns the request query parameter with the specified name.

function GetQueryParameter(const aName: string): string

Parameters:

• aName: Name of parameter

---

Returns the corresponding part of the HTTP query string.

function GetQueryString: string

---

function GetStrippedTargetUrl: string

---

Returns itself.

function GetTransportObject: TObject

---

Returns the User-Agent header value of the current request when overridden.

function GetUserAgent: string

---

This method is called when incoming data is present.

procedure HasData(aId: Integer; aData: TStream)

Parameters:

• aId:
• aData:

---

The timeout, in milliseconds, after which the client channel will abort the request. This ensures that for unresponsive servers, the client will not hang indefinitely waiting for a reply.

The default value is 10000 (milliseconds, i.e. 10 seconds).

property HTTPRequestTimeout: Integer read write

---

Returns current state

function InDestroyingState: Boolean

---

function InitialConnect: Boolean

---

Sets CurrentLocator

function InitServerLocator: Integer

---

procedure InitWorkerThread

---

Indicates whether an answer is received after an InvokeRequest.

function InvokeRequest(aRequest: TStream; aGetResponse: Boolean): string

Parameters:

• aRequest: Id of a waiting response
• aGetResponse: Response data

---

Checks if encryption was used

function IsEncryptionUsed: Boolean

---

property IsProbeMode: Boolean read

---

Checks state of stream

function IsStreamEncrypted(Source: TStream): Boolean

Parameters:

• Source: Stream

---

procedure LaunchAsyncTask(aRequest: IROAsyncRequest)

Parameters:

• aRequest:

---

property LoadBalancerLocatorIdx: Integer read write

---

Loads SSL library if SSL protocol is used

procedure LoadSSL

---

Sets the maximum size for data packages that the channel will transport (default is 10485760, 10 MB).

property MaxPackageSize: Integer read write

---

The minimal size when GZIP encoding will be used (default is 4096 bytes)

property MinSizeForGzipEncoding: Integer read write

---

Specifies that server response should be decoded

property NeedDecodeResponse: Boolean read write

---

Forwards notification messages to all owned components.

procedure Notification(AComponent: TComponent; Operation: TOperation)

Parameters:

• AComponent: component
• Operation: operation

---

Fired after stream was encrypted

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

---

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

---

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

---

Fires when exception is raised in asynchronous mode

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

---

Fired before stream will be decrypted

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

---

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

• check or adjust the server configuration
• to include/exclude the server from being probed by changing the TROServerLocator property.

property OnBeforeProbingServer: TROBeginProbeServerEvent read write

---

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

---

Fires when channel is connected to server

property OnConnected: TNotifyEvent read write

---

Fires when the active connection to the server has been dropped or lost.

property OnDisconnected: TNotifyEvent read write

---

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)

---

Fires when the server returns a response with error code for an unregistered connection with the client.

property OnInvalidClientID: TROOnInvalidClientIdHandler read write
delegate:  procedure OnInvalidClientID(Sender: TObject; var aReconnect: Boolean)

---

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

---

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

---

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

---

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

---

Fires before changing of a server locator.

property OnServerLocatorAssignment: TServerLocatorAssignment read write

---

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

---

Checks the availability of all known servers.

procedure ProbeAll

---

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

---

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

---

procedure ProcessEvent(aData: TStream)

Parameters:

• aData:

---

The time interval to pass between reconnect attempts, in millisecnds. The default is 500 (0.5 second).

property ReconnectDelay: Integer read write

---

property ReconnectEvent: TROEvent read

---

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.

---

The timeout to complete the remote request on the server. Expressed in milliseconds, the default value is 60000 (60 sec). All requests that last longer than the timeout specified are considered failed.

property RequestTimeout: Integer read write

---

Resets channel that is used for probing

procedure ResetProbingClone(aProbe: TROTransportChannel)

Parameters:

• aProbe: Probing clone

---

Returns server-side RODL.

procedure RetrieveMetadata(out Dest: TStream)

Parameters:

• Dest: Stream

---

Indicates whether an answer is received after an InvokeRequest.

procedure RetrieveResponse(const aMessageID: string; aResponse: TStream)

Parameters:

• aMessageID: Id of a waiting response
• aResponse: Response data

---

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

---

procedure ReturnChannelToPool(aChannel: TROTransportChannel)

Parameters:

• aChannel:

---

function ROActiveAsyncTransportChannel_InvokeRequest(aRequest: TStream; aGetResponse: Boolean; aEvent: TROEvent): string

Parameters:

• aRequest:
• aGetResponse:
• aEvent:

---

Forwards notification messages to all owned components.

procedure ROFreeNotification(aComponent: TComponent)

Parameters:

• aComponent: component

---

Forwards notification messages to all owned components.

procedure RORemoveFreeNotification(aComponent: TComponent)

Parameters:

• aComponent: component

---

Forwards notification messages to all owned components.

procedure SendRemoveNotification(aComponent: TComponent)

Parameters:

• aComponent: component

---

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 ServerAcceptEncodingModes: TROHTTPAcceptEncodingModes read write

---

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

---

GUID that uniquely identifies each client and allows the server to determine which calls are received from the same client. This property is used for Session Management.

property SessionId: TGUID read write

---

procedure SetAsyncBusy(const Value: Boolean)

Parameters:

• Value:

---

procedure SetConnectedState

---

Sets the new value of the client's header with the specified value when overridden.

procedure SetHeaders(aWaitingThread: Boolean; const aName: string; const aValue: string)

Parameters:

• aWaitingThread: Specifies which implementation will be used
• aName: Specified client's header name
• aValue: Specified client's header value

---

procedure SetInactive

---

Sets a virtual path to the specified service when overridden.

procedure SetPathInfo(const aValue: string)

Parameters:

• aValue: Specified virtual path

---

Retrieves the location details of a server from aServerLocator.

procedure SetServerLocator(aServerLocator: TROServerLocator; anException: Exception)

Parameters:

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

---

Sets the new value of the User-Agent header of the current request when overridden.

procedure SetUserAgent(const aValue: string)

Parameters:

• aValue: Specified value of the User-Agent header

---

Controls whether the Active property value is stored in the dfm file.

property StoreActive: Boolean read write

---

procedure SuperChannel_RaiseError(aCode: Integer)

Parameters:

• aCode:

---

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

---

According to the superchannel nature every remote request is processed using it's own background thread. This property controls on which thread to execute the event handlers for events connected with each remote request. If the property is set to true than all event handlers are executed on the main application thread, otherwise they are executed on the request's background thread.
WARNING: This property has no effect on OnSendStream and OnReceiveStream events, they are always executed in main thread.

property SynchronizeEvents: Boolean read write

---

Target URI

property TargetUri: TROUri read write

---

The address of the server.

property TargetUrl: string read write

---

procedure TerminateWorkerThread

---

property ThreadSafe: Boolean read write

---

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

---

Unregisters the specified IROEventReceiver aReceiver in the specified channel.

procedure UnregisterEventReceiver(aReceiver: IROEventReceiver)

Parameters:

• aReceiver: The event receiver that should be unregistered.

---

Unregisters the all event receivers in the specified channel.

procedure UnregisterEventReceivers

---

procedure WaitForActive(const aTimeout: Integer)

Parameters:

• aTimeout:

---

Internal storage of remote requests awaiting for response.

property WaitingRequests: TThreadList<TROWaitingRequest> read

---

Internal background threads management property.

property WorkerThread: TThread read

 

Allows to get channel's activity state, whether the channel active i.e. attempts to connect or already connected. Allows to activate and deactivate the channel.

property Active: Boolean read write

---

Allows to use GZIP compression

property AllowGzipEncoding: Boolean read write

---

Specifies whether to use auto reconnect feature if the specified server is not available.

property AutoReconnect: Boolean read write

---

Controls the auto-reconnect behavior, if enabled. For possible auto-reconnect modes see TROSCAutoReconnectBehavior enum.

property AutoReconnectBehavior: TROSCAutoReconnectBehavior read write

---

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

---

The unique identifier of the client and it's session on the server. See TROMessage description for more details. The property is assigned automatically during the process of data exchange between the client and the server.

property ClientId: TGUID read write

---

Provides direct access to the underlying Synapse implementation. You can use this property to control advanced settings on the Synapse object.

property ClientRequest: THTTPSend read

---

Provides direct access to the underlying Synapse implementation. You can use this property to control advanced settings on the Synapse object.

property ClientWait: THTTPSend read

---

Returns true if the channel is connected to the server.

property Connected: Boolean read

---

Identifies a connection to this client on the server. Note that the value of this property does not necessarily correspond with the session ID on the server side.

property ConnectionId: TGUID read write

---

The timeout to establish connection to the server. Expressed in milliseconds, the default value is 10000 (10 sec).

property ConnectionWaitTimeout: Integer read write

---

Connection timeout

property ConnectTimeout: Integer read write

---

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

---

Controls whether data packets are sent individually or if small packets are held back to send as part of fewer larger data packets. Normally, you will want this disabled as it can have a significant effect on performance. The only time when its worth keeping the property enabled is when there are many small packets to be sent and you need to keep network bandwidth to a minimum.

See more at Nagle's algorithm

property DisableNagle: Boolean read write

---

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

---

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

---

Provides a list of registered IROEventReceiver

property EventReceiverList: TInterfaceList read

---

Refers to the TROThreadPool instance to provide a thread pool to execute event handling routines on. If the thread pool is not set explicitly it is created autromatically upon access.

property EventThreadPool: TROThreadPool read write

---

property FaultToleranceLocatorIdx: Integer read write

---

The timeout, in milliseconds, after which the client channel will abort the request. This ensures that for unresponsive servers, the client will not hang indefinitely waiting for a reply.

The default value is 10000 (milliseconds, i.e. 10 seconds).

property HTTPRequestTimeout: Integer read write

---

property IsProbeMode: Boolean read

---

property LoadBalancerLocatorIdx: Integer read write

---

Sets the maximum size for data packages that the channel will transport (default is 10485760, 10 MB).

property MaxPackageSize: Integer read write

---

The minimal size when GZIP encoding will be used (default is 4096 bytes)

property MinSizeForGzipEncoding: Integer read write

---

Specifies that server response should be decoded

property NeedDecodeResponse: Boolean read write

---

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

---

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

---

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

• check or adjust the server configuration
• to include/exclude the server from being probed by changing the TROServerLocator property.

property OnBeforeProbingServer: TROBeginProbeServerEvent read write

---

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

---

Fires when channel is connected to server

property OnConnected: TNotifyEvent read write

---

Fires when the active connection to the server has been dropped or lost.

property OnDisconnected: TNotifyEvent read write

---

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

---

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

---

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

---

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

---

Fires before changing of a server locator.

property OnServerLocatorAssignment: TServerLocatorAssignment read write

---

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

---

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

---

The time interval to pass between reconnect attempts, in millisecnds. The default is 500 (0.5 second).

property ReconnectDelay: Integer read write

---

The timeout to complete the remote request on the server. Expressed in milliseconds, the default value is 60000 (60 sec). All requests that last longer than the timeout specified are considered failed.

property RequestTimeout: Integer read write

---

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 ServerAcceptEncodingModes: TROHTTPAcceptEncodingModes read write

---

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

---

GUID that uniquely identifies each client and allows the server to determine which calls are received from the same client. This property is used for Session Management.

property SessionId: TGUID read write

---

Controls whether the Active property value is stored in the dfm file.

property StoreActive: Boolean read write

---

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

---

According to the superchannel nature every remote request is processed using it's own background thread. This property controls on which thread to execute the event handlers for events connected with each remote request. If the property is set to true than all event handlers are executed on the main application thread, otherwise they are executed on the request's background thread.
WARNING: This property has no effect on OnSendStream and OnReceiveStream events, they are always executed in main thread.

property SynchronizeEvents: Boolean read write

---

Target URI

property TargetUri: TROUri read write

---

The address of the server.

property TargetUrl: string read write

---

property ThreadSafe: Boolean read write

---

Internal storage of remote requests awaiting for response.

property WaitingRequests: TThreadList<TROWaitingRequest> read

---

Internal background threads management property.

property WorkerThread: TThread read

 

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

---

class function ChannelMatchingTargetUrl(const aUrl: string): TROTransportChannel

Parameters:

• aUrl:

 

Standard component constructor

constructor Create(aOwner: TComponent)

Parameters:

• aOwner: Owner

---

Copies the contents of another, similar object.

procedure Assign(Source: TPersistent)

Parameters:

• Source: Instance whose properties will be copied

---

Copies the events of another, similar object.

procedure AssignEvents(aSource: TROTransportChannel)

Parameters:

• aSource: Instance whose properties will be copied

---

Copies the specific properties of another, similar object.

procedure AssignSpecificProperties(aSource: TROTransportChannel)

Parameters:

• aSource: Instance whose properties will be copied

---

Notifies about an exception in an asynchronous mode.

procedure AsyncException(aAsyncInterface: IROAsyncInterface; AsyncException: Exception)

Parameters:

• aAsyncInterface: Exception source
• AsyncException: Exception data

---

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

procedure BeforeDispatch(aMessage: IROMessage)

Parameters:

• aMessage: Message

---

Calculates size of incoming package.

function CalcRequestStreamSize(const aData: TStream): Integer

Parameters:

• aData: Incoming package

---

Sends event to each registered IROEventReceiver

procedure CallbackEvents(aData: TStream; aThread: TThread)

Parameters:

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

---

Cancels the specified request to stop the threads when overridden.

procedure CancelRequest(aWaitingThread: Boolean)

Parameters:

• aWaitingThread: Specified waiting thread that should be stopped

---

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

Parameters:

• aFaultStartLocatorIdx:
• aRetry:
• aException:

---

Validates channel properties

procedure CheckProperties

---

Indicates whether an answer is received after an InvokeRequest.

function CheckStatus(const aMessageID: string): Boolean

Parameters:

• aMessageID: Value of the previously called InvokeRequest result

---

function CreateWorkerThread: TThread

---

Decrypt stream

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

Parameters:

• Source: Source
• Dest: Destination

---

Decrypt stream

procedure DecryptStream(const Stream: TStream)

Parameters:

• Stream: Stream

---

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

---

Dispatches the HTTP request to the server and gets the response when overridden.

procedure DispatchHTTPRequest(aWaitingThread: Boolean; aRequest: TStream; out aResponse: TStream)

Parameters:

• aWaitingThread: If true, this parameter uses the HTTP client for the waiting thread instead of the requesting thread
• aRequest: Request body
• aResponse: Response data

---

Fires OnAfterProbingServer event

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

Parameters:

• aServerLocator: Server locator
• aFailed:

---

Fires OnAfterProbingServer event

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

Parameters:

• aProbedCount:
• aEnabledCount:
• aDisabledCount:

---

procedure DoBeforeDecryptEvent(aEncryptedStream: TStream)

Parameters:

• aEncryptedStream: Stream

---

Fires OnBeforeProbingServer event

procedure DoBeforeProbingServerEvent(const aServerLocator: TROServerLocator)

Parameters:

• aServerLocator: Server locator

---

Fires OnBeforeProbingServers event

procedure DoBeforeProbingServersEvent

---

Performs GZIP decoding

procedure DoDecodeStream(const aSource: TStream; const aDest: TStream)

Parameters:

• aSource: Source
• aDest: Destination

---

Performs GZIP encoding

procedure DoEncodeStream(const aSource: TStream)

Parameters:

• aSource: Source

---

Calls OnInvalidClientID event

procedure DoInvalidClientIDEvent(var aReconnect: Boolean)

Parameters:

• aReconnect: Allows reconnect

---

Detects SSL state

function DoNeedSSL: Boolean

---

function DoProcessError(const aId: Integer; const aErrorNo: Integer): Boolean

Parameters:

• aId:
• aErrorNo:

---

Fires OnSendStream event

procedure DoReceiveStreamEvent(const Dest: TStream)

Parameters:

• Dest: Stream

---

procedure DoReconnect(var aRestartLoop: Boolean)

Parameters:

• aRestartLoop:

---

Fires OnSendStream event

procedure DoSendStreamEvent(const Source: TStream)

Parameters:

• Source: Stream

---

Fires OnServerLocatorAssignment event

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

Parameters:

• aLocator:
• aException:

---

Encrypt stream

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

Parameters:

• Source: Source
• Dest: Destination

---

Encrypt stream

procedure EncryptStream(const Stream: TStream)

Parameters:

• Stream: Stream

---

function FindWaitingRequest(aList: TList<TROWaitingRequest>; aId: Integer): TROWaitingRequest

Parameters:

• aList:
• aId:

---

Returns current channel state

function GetBusy: Boolean

---

Gets CanUseContentEncoding value.

function GetCanUseContentEncoding: Boolean

---

function GetChannelFromPool: TROTransportChannel

---

Returns the host URL with the prefix 'http' when overridden.

function GetLocation: string

---

Returns the virtual path to the specified service when overridden.

function GetPathInfo: string

---

Returns the request query parameter with the specified name.

function GetQueryParameter(const aName: string): string

Parameters:

• aName: Name of parameter

---

Returns the corresponding part of the HTTP query string.

function GetQueryString: string

---

function GetStrippedTargetUrl: string

---

Returns itself.

function GetTransportObject: TObject

---

Returns the User-Agent header value of the current request when overridden.

function GetUserAgent: string

---

This method is called when incoming data is present.

procedure HasData(aId: Integer; aData: TStream)

Parameters:

• aId:
• aData:

---

Returns current state

function InDestroyingState: Boolean

---

function InitialConnect: Boolean

---

Sets CurrentLocator

function InitServerLocator: Integer

---

procedure InitWorkerThread

---

Indicates whether an answer is received after an InvokeRequest.

function InvokeRequest(aRequest: TStream; aGetResponse: Boolean): string

Parameters:

• aRequest: Id of a waiting response
• aGetResponse: Response data

---

Checks if encryption was used

function IsEncryptionUsed: Boolean

---

Checks state of stream

function IsStreamEncrypted(Source: TStream): Boolean

Parameters:

• Source: Stream

---

procedure LaunchAsyncTask(aRequest: IROAsyncRequest)

Parameters:

• aRequest:

---

Loads SSL library if SSL protocol is used

procedure LoadSSL

---

Forwards notification messages to all owned components.

procedure Notification(AComponent: TComponent; Operation: TOperation)

Parameters:

• AComponent: component
• Operation: operation

---

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

---

Checks the availability of all known servers.

procedure ProbeAll

---

procedure ProcessEvent(aData: TStream)

Parameters:

• aData:

---

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.

---

Resets channel that is used for probing

procedure ResetProbingClone(aProbe: TROTransportChannel)

Parameters:

• aProbe: Probing clone

---

Returns server-side RODL.

procedure RetrieveMetadata(out Dest: TStream)

Parameters:

• Dest: Stream

---

Indicates whether an answer is received after an InvokeRequest.

procedure RetrieveResponse(const aMessageID: string; aResponse: TStream)

Parameters:

• aMessageID: Id of a waiting response
• aResponse: Response data

---

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

---

procedure ReturnChannelToPool(aChannel: TROTransportChannel)

Parameters:

• aChannel:

---

function ROActiveAsyncTransportChannel_InvokeRequest(aRequest: TStream; aGetResponse: Boolean; aEvent: TROEvent): string

Parameters:

• aRequest:
• aGetResponse:
• aEvent:

---

Forwards notification messages to all owned components.

procedure ROFreeNotification(aComponent: TComponent)

Parameters:

• aComponent: component

---

Forwards notification messages to all owned components.

procedure RORemoveFreeNotification(aComponent: TComponent)

Parameters:

• aComponent: component

---

Forwards notification messages to all owned components.

procedure SendRemoveNotification(aComponent: TComponent)

Parameters:

• aComponent: component

---

procedure SetAsyncBusy(const Value: Boolean)

Parameters:

• Value:

---

procedure SetConnectedState

---

Sets the new value of the client's header with the specified value when overridden.

procedure SetHeaders(aWaitingThread: Boolean; const aName: string; const aValue: string)

Parameters:

• aWaitingThread: Specifies which implementation will be used
• aName: Specified client's header name
• aValue: Specified client's header value

---

procedure SetInactive

---

Sets a virtual path to the specified service when overridden.

procedure SetPathInfo(const aValue: string)

Parameters:

• aValue: Specified virtual path

---

Retrieves the location details of a server from aServerLocator.

procedure SetServerLocator(aServerLocator: TROServerLocator; anException: Exception)

Parameters:

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

---

Sets the new value of the User-Agent header of the current request when overridden.

procedure SetUserAgent(const aValue: string)

Parameters:

• aValue: Specified value of the User-Agent header

---

procedure SuperChannel_RaiseError(aCode: Integer)

Parameters:

• aCode:

---

procedure TerminateWorkerThread

---

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

---

Unregisters the specified IROEventReceiver aReceiver in the specified channel.

procedure UnregisterEventReceiver(aReceiver: IROEventReceiver)

Parameters:

• aReceiver: The event receiver that should be unregistered.

---

Unregisters the all event receivers in the specified channel.

procedure UnregisterEventReceivers

---

procedure WaitForActive(const aTimeout: Integer)

Parameters:

• aTimeout:

 

property ConnectEvent: TROEvent read

---

Fired after stream was encrypted

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

---

Fires when exception is raised in asynchronous mode

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

---

Fired before stream will be decrypted

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

---

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)

---

Fires when the server returns a response with error code for an unregistered connection with the client.

property OnInvalidClientID: TROOnInvalidClientIdHandler read write
delegate:  procedure OnInvalidClientID(Sender: TObject; var aReconnect: Boolean)

---

property ReconnectEvent: TROEvent read