AzureRelayReceiver Component

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An Azure Relay Service listener to accept and communicate with clients.

Syntax

TipqAzureRelayReceiver

Remarks

The AzureRelayReceiver component implements the listener role in the Azure Relay service. The component will connect to the server and listen for incoming connections. Once a connection is established data can be exchange freely in both directions allowing a flexible messaging environment.

Authenticating and Listening

Authentication to Azure Relay is performed using the Shared Access Key Name and Shared Access Key created from the Azure portal for the Relay. To begin listening for incoming connections set Listening to True.

When set to True the component will immediately attempt to make a connection to the Azure Relay Service and begin listening. The following properties are applicable when setting Listening:

• AccessKey (required)
• AccessKeyName (required)
• HybridConnection (required)
• NamespaceAddress (required)
• DefaultTimeout
• ForwardingHost
• ForwardingPort

To stop listening set Listening to False. To shutdown the server including existing connections call Shutdown.

Handling Connections

When a connection is made the ConnectionRequest event fires with information about the connecting client. From within this event the client connection may be accepted (default) or rejected.

If the client connection is accepted the ConnectionConnected and ConnectionReadyToSend events fire when the connection completes and is ready to send and receive data.

When data is received from the client the ConnectionDataIn event fires with the received data.

To send data to the client set DataToSend or call Send, SendFile, or SendText.

When the client disconnects the ConnectionDisconnected event fires. To initiate the client disconnection call Disconnect.

Handling HTTP Connections

Azure Relay also supports HTTP connections which follow a request/response model. When an HTTP request is received the HTTPRequest event fires with information about the request including the request body. Save the ConnectionId value obtained within HTTPRequest for use with SendHTTPResponse.

To send a HTTP response call SendHTTPResponse with the ConnectionId, status code and description, and any response day to be sent back to the client.

Forwarding Connections

The component supports forwarding incoming connection to a separate destination. This functionality allows AzureRelayReceiver to act as a proxy for incoming requests. When ForwardingHost and ForwardingPort are set anytime a connection is made the component will establish a separate connection to the ForwardingHost and forward all incoming traffic. Responses from the ForwardingHost are then automatically sent back over the connection.

When connection forwarding is used no special steps are needed to send or receive data. Data flows freely between the connected client and the ForwardingHost.

Note: Forwarding is not supported for HTTP requests.

Code Example (WebSockets)

Azurerelayreceiver listener = new Azurerelayreceiver(); listener.AccessKey = "9oKRDwjl0s440MlLUi4qHxDL34j1FS6K3t5TRoJ216c="; listener.AccessKeyName = "RootManageSharedAccessKey"; listener.NamespaceAddress = "myrelay.servicebus.windows.net"; listener.HybridConnection = "hc1"; listener.OnConnectionRequest += (s, e) => { Console.WriteLine("Connection Request From: " + e.RemoteAddress + ":" + e.RemotePort); e.Accept = true; }; listener.OnConnectionReadyToSend += (s, e) => { Console.WriteLine("Connection [" + e.ConnectionId + "] connected and ready to send and receive."); }; listener.OnConnectionDataIn += (s, e) => { Console.WriteLine("Received data from " + e.ConnectionId + ": " + e.Text); //echo the data back listener.SendText(e.ConnectionId, e.Text); Console.WriteLine("Echoed received data back"); }; listener.Listening = true; while (true) listener.DoEvents();

Code Example (HTTP)

Azurerelaylistener listener = new Azurerelaylistener(); listener.AccessKey = "9oKRDwjl0s440MlLUi4qHxDL34j1FS6K3t5TRoJ216c="; listener.AccessKeyName = "RootManageSharedAccessKey"; listener.NamespaceAddress = "myrelay.servicebus.windows.net"; listener.HybridConnection = "hc1"; listener.OnHTTPRequest += (s, e) => { Console.WriteLine("HTTP Request from " + e.RemoteAddress + ":" + e.RemotePort); Console.WriteLine("HTTP Method: " + e.RequestMethod); Console.WriteLine("HTTP Request: " + e.RequestData); myConnectionId = e.ConnectionId; }; //Send a response using the ConnectionId value from the HTTPRequest event listener.SendHTTPResponse(myConnectionId, 200, "OK", myResponseBody);

Property List

The following is the full list of the properties of the component with short descriptions. Click on the links for further details.

Method List

The following is the full list of the methods of the component with short descriptions. Click on the links for further details.

Event List

The following is the full list of the events fired by the component with short descriptions. Click on the links for further details.

Config Settings

The following is a list of config settings for the component with short descriptions. Click on the links for further details.

AccessKey Property (AzureRelayReceiver Component)

The Shared Access Key.

Syntax

property AccessKey: String read get_AccessKey write set_AccessKey;

Default Value

''

Remarks

This property specifies the Shared Access Key to use when authenticating. This is the primary or secondary key of the shared access policy created in the Azure portal. For instance 8oKRDwkl0s440MlLUi4qHxDL34j1FS6K3t5TRoJ216c=.

AccessKeyName Property (AzureRelayReceiver Component)

The Shared Access Key Name.

Syntax

property AccessKeyName: String read get_AccessKeyName write set_AccessKeyName;

Default Value

''

Remarks

This property specifies the Shared Access Key name to use when authenticating. This is the name of the shared access policy created in the Azure portal. For instance RootManageSharedAccessKey.

Connected Property (AzureRelayReceiver Component)

Whether the component is connected.

Syntax

property Connected: Boolean read get_Connected;

Default Value

false

Remarks

This property is used to determine whether or not the component is connected to the remote host. Use the Connect and Disconnect methods to manage the connection.

This property is read-only and not available at design time.

Connections Property (AzureRelayReceiver Component)

A collection of currently connected clients.

Syntax

property Connections: TipqAzureRelayConnectionList read get_Connections;

Remarks

This property is a collection of currently connected clients. All of the connections may be managed using this property. Each connection is described by the different fields of the AzureRelayConnection type.

This collection is a hashtable type of collection, in which the connection Id string is used as the key to the desired connection. The connection Id is present when events such as the ConnectionConnected event fires.

This property is read-only.

DefaultTimeout Property (AzureRelayReceiver Component)

An initial timeout value to be used by incoming connections.

Syntax

property DefaultTimeout: Integer read get_DefaultTimeout write set_DefaultTimeout;

Default Value

0

Remarks

This property is used by the component to set the operational timeout value of all inbound connections once they are established.

By default, the timeout is 0, meaning that all inbound connections will behave asynchronously.

Firewall Property (AzureRelayReceiver Component)

A set of properties related to firewall access.

Syntax

property Firewall: TipqFirewall read get_Firewall write set_Firewall;

Remarks

This is a Firewall-type property, which contains fields describing the firewall through which the component will attempt to connect.

ForwardingHost Property (AzureRelayReceiver Component)

The address to which traffic will automatically be forwarded.

Syntax

property ForwardingHost: String read get_ForwardingHost write set_ForwardingHost;

Default Value

''

Remarks

ForwardingHost optionally specifies an address to which traffic will be automatically forwarded. Traffic will only be forwarded if both ForwardingHost and ForwardingPort are specified.

When a connection is made the component will automatically establish a connection to ForwardingHost on the port specified by ForwardingPort. Data will then flow freely between the connected client and the ForwardingHost.

Note: This functionality is not applicable to HTTP requests.

ForwardingPort Property (AzureRelayReceiver Component)

The port to which traffic will automatically be forwarded.

Syntax

property ForwardingPort: Integer read get_ForwardingPort write set_ForwardingPort;

Default Value

0

Remarks

ForwardingPort is used together with ForwardingHost to define a location where traffic is automatically forwarded.

ForwardingHost optionally specifies an address to which traffic will be automatically forwarded. Traffic will only be forwarded if both ForwardingHost and ForwardingPort are specified.

When a connection is made the component will automatically establish a connection to ForwardingHost on the port specified by ForwardingPort. Data will then flow freely between the connected client and the ForwardingHost.

Note: This functionality is not applicable to HTTP requests.

HybridConnection Property (AzureRelayReceiver Component)

The hybrid connection name.

Syntax

property HybridConnection: String read get_HybridConnection write set_HybridConnection;

Default Value

''

Remarks

This setting specifies the name of the hybrid connection that was created in the Azure portal. For instance hc1.

Listening Property (AzureRelayReceiver Component)

If , the component is listening for incoming connections.

Syntax

property Listening: Boolean read get_Listening write set_Listening;

Default Value

false

Remarks

This setting indicates whether the component accepts incoming connections. When True the component has connected to the Azure Service and started listening for incoming connections. The initiate the connection and begin listening call the StartListening method.

Use the StartListening and StopListening methods to control whether the component is listening.

This property is not available at design time.

LocalHost Property (AzureRelayReceiver Component)

The name of the local host or user-assigned IP interface through which connections are initiated or accepted.

Syntax

property LocalHost: String read get_LocalHost write set_LocalHost;

Default Value

''

Remarks

This property contains the name of the local host as obtained by the gethostname() system call, or if the user has assigned an IP address, the value of that address.

In multihomed hosts (machines with more than one IP interface) setting LocalHost to the IP address of an interface will make the component initiate connections (or accept in the case of server components) only through that interface. It is recommended to provide an IP address rather than a hostname when setting this property to ensure the desired interface is used.

If the component is connected, the LocalHost property shows the IP address of the interface through which the connection is made in internet dotted format (aaa.bbb.ccc.ddd). In most cases, this is the address of the local host, except for multihomed hosts (machines with more than one IP interface).

Note: LocalHost is not persistent. You must always set it in code, and never in the property window.

NamespaceAddress Property (AzureRelayReceiver Component)

The namespace address of the relay.

Syntax

property NamespaceAddress: String read get_NamespaceAddress write set_NamespaceAddress;

Default Value

''

Remarks

This property specifies the full fully qualified domain name of the relay namespace. For instance myrelay.servicebus.windows.net.

Proxy Property (AzureRelayReceiver Component)

A set of properties related to proxy access.

Syntax

property Proxy: TipqProxy read get_Proxy write set_Proxy;

Remarks

This property contains fields describing the proxy through which the component will attempt to connect.

SSLAcceptServerCert Property (AzureRelayReceiver Component)

Instructs the component to unconditionally accept the server certificate that matches the supplied certificate.

Syntax

property SSLAcceptServerCert: TipqCertificate read get_SSLAcceptServerCert write set_SSLAcceptServerCert;

Remarks

If it finds any issues with the certificate presented by the server, the component will normally terminate the connection with an error.

You may override this behavior by supplying a value for SSLAcceptServerCert. If the certificate supplied in SSLAcceptServerCert is the same as the certificate presented by the server, then the server certificate is accepted unconditionally, and the connection will continue normally.

Note: This functionality is provided only for cases in which you otherwise know that you are communicating with the right server. If used improperly, this property may create a security breach. Use it at your own risk.

SSLCert Property (AzureRelayReceiver Component)

The certificate to be used during Secure Sockets Layer (SSL) negotiation.

Syntax

property SSLCert: TipqCertificate read get_SSLCert write set_SSLCert;

Remarks

This property includes the digital certificate that the component will use during SSL negotiation. Set this property to a valid certificate before starting SSL negotiation. To set a certificate, you may set the Encoded field to the encoded certificate. To select a certificate, use the store and subject fields.

SSLProvider Property (AzureRelayReceiver Component)

The Secure Sockets Layer/Transport Layer Security (SSL/TLS) implementation to use.

Syntax

property SSLProvider: TipqTSSLProviders read get_SSLProvider write set_SSLProvider;

TipqTSSLProviders = (
  sslpAutomatic,
  sslpPlatform,
  sslpInternal
);

Default Value

sslpAutomatic

Remarks

This property specifies the SSL/TLS implementation to use. In most cases the default value of 0 (Automatic) is recommended and should not be changed. When set to 0 (Automatic), the component will select whether to use the platform implementation or the internal implementation depending on the operating system as well as the TLS version being used.

Possible values are as follows:

In most cases using the default value (Automatic) is recommended. The component will select a provider depending on the current platform.

When Automatic is selected, on Windows, the component will use the platform implementation. On Linux/macOS, the component will use the internal implementation. When TLS 1.3 is enabled via SSLEnabledProtocols, the internal implementation is used on all platforms.

SSLServerCert Property (AzureRelayReceiver Component)

The server certificate for the last established connection.

Syntax

property SSLServerCert: TipqCertificate read get_SSLServerCert;

Remarks

This property contains the server certificate for the last established connection.

SSLServerCert is reset every time a new connection is attempted.

This property is read-only.

Config Method (AzureRelayReceiver Component)

Sets or retrieves a configuration setting.

Syntax

function Config(ConfigurationString: String): String;

Remarks

Config is a generic method available in every component. It is used to set and retrieve configuration settings for the component.

These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the component, access to these internal properties is provided through the Config method.

To set a configuration setting named PROPERTY, you must call Config("PROPERTY=VALUE"), where VALUE is the value of the setting expressed as a string. For boolean values, use the strings "True", "False", "0", "1", "Yes", or "No" (case does not matter).

To read (query) the value of a configuration setting, you must call Config("PROPERTY"). The value will be returned as a string.

Disconnect Method (AzureRelayReceiver Component)

This method disconnects the specified client.

Syntax

procedure Disconnect(ConnectionId: Integer);

Remarks

Calling this method will disconnect the client specified by the ConnectionId parameter.

DoEvents Method (AzureRelayReceiver Component)

This method processes events from the internal message queue.

Syntax

procedure DoEvents();

Remarks

When DoEvents is called, the component processes any available events. If no events are available, it waits for a preset period of time, and then returns.

Interrupt Method (AzureRelayReceiver Component)

Interrupts a synchronous send to the remote host.

Syntax

procedure Interrupt(ConnectionId: Integer);

Remarks

This property is called using the Connection ID if you wish to interrupt a connection and stop a file from uploading without disconnecting the client connected to the component. If you use SendFile to upload a file, the component will run synchronously on that Connection ID until it is completed.

PauseData Method (AzureRelayReceiver Component)

This method pauses data reception.

Syntax

procedure PauseData(ConnectionId: Integer);

Remarks

This method pauses data reception for the connection identified by ConnectionId when called. While data reception is paused, the DataIn event will not fire for the specified connection. Call ProcessData to reenable data reception.

ProcessData Method (AzureRelayReceiver Component)

This method reenables data reception after a call to PauseData .

Syntax

procedure ProcessData(ConnectionId: Integer);

Remarks

This method reenables data reception for the connection identified by ConnectionId after a previous call to PauseData. When PauseData is called, the DataIn event will not fire for the specified connection. To reenable data reception and allow DataIn to fire, call this method.

Note: This method is used only after previously calling PauseData. It does not need to be called to process incoming data by default.

Send Method (AzureRelayReceiver Component)

This method sends binary data to the client.

Syntax

procedure Send(ConnectionId: Integer; Data: TBytes);

Remarks

This method sends the binary data specified by Data to the client specified by ConnectionId.

SendBytes Method (AzureRelayReceiver Component)

This method sends binary data to the specified client.

Syntax

procedure SendBytes(ConnectionId: Integer; Data: TBytes);

Remarks

This method sends binary data to the client identified by ConnectionId. To send text, use the SendText method instead.

When Timeout is set to 0, the component will behave asynchronously. If you are sending data to the remote host faster than it can process it, or faster than the network's bandwidth allows, the outgoing queue might fill up. When this happens, the operation raises the exception with errorcode 10035 and message '[10035] Operation would block' (WSAEWOULDBLOCK). You can handle this exception, and then try to send the data again. . The BytesSent property shows how many bytes were sent (if any). If 0 bytes were sent, then you can wait for the ReadyToSend event before attempting to send data again.

Note: The ReadyToSend event is not fired when part of the data is sent successfully.

SendFile Method (AzureRelayReceiver Component)

This method sends the file to the remote host.

Syntax

procedure SendFile(ConnectionId: Integer; FileName: String);

Remarks

This method sends the file to the client specified by the ConnectionId.

SendHTTPResponse Method (AzureRelayReceiver Component)

Send the HTTP response.

Syntax

procedure SendHTTPResponse(ConnectionId: Integer; StatusCode: Integer; StatusDescription: String; ResponseData: TBytes);

Remarks

This method sends an HTTP response to the HTTP request identified by ConnectionId.

The response status code and description, as well as the response body, are sent to the client using this method. The ConnectionId value should be obtained from the HTTPRequest event.

StatusCode is the three digit HTTP status code to return, for instance 200.

StatusDescription is the text corresponding to the StatusCode. For instance OK.

ResponseBody specifies the body to be sent back to the client (if any).

Code Example (HTTP)

Azurerelaylistener listener = new Azurerelaylistener(); listener.AccessKey = "9oKRDwjl0s440MlLUi4qHxDL34j1FS6K3t5TRoJ216c="; listener.AccessKeyName = "RootManageSharedAccessKey"; listener.NamespaceAddress = "myrelay.servicebus.windows.net"; listener.HybridConnection = "hc1"; listener.OnHTTPRequest += (s, e) => { Console.WriteLine("HTTP Request from " + e.RemoteAddress + ":" + e.RemotePort); Console.WriteLine("HTTP Method: " + e.RequestMethod); Console.WriteLine("HTTP Request: " + e.RequestData); myConnectionId = e.ConnectionId; }; //Send a response using the ConnectionId value from the HTTPRequest event listener.SendHTTPResponse(myConnectionId, 200, "OK", myResponseBody);

SendText Method (AzureRelayReceiver Component)

This method sends text data to the client.

Syntax

procedure SendText(ConnectionId: Integer; Text: String);

Remarks

This method sends text to the client identified by ConnectionId. To send binary data, use the SendBytes method instead.

When Timeout is set to 0, the component will behave asynchronously. If you are sending data to the remote host faster than it can process it, or faster than the network's bandwidth allows, the outgoing queue might fill up. When this happens, the operation raises the exception with errorcode 10035 and message '[10035] Operation would block' (WSAEWOULDBLOCK). You can handle this exception, and then try to send the data again. . The BytesSent property shows how many bytes were sent (if any). If 0 bytes were sent, then you can wait for the ReadyToSend event before attempting to send data again.

Note: The ReadyToSend event is not fired when part of the data is sent successfully.

This method sends text to the client identified by ConnectionId. Data sent with this method will always be treated as text data regardless of the value of DataFormat. The component will UTF-8 encode the supplied text.

Shutdown Method (AzureRelayReceiver Component)

This method shuts down the server.

Syntax

procedure Shutdown();

Remarks

This method shuts down the server. Calling this method is equivalent to calling StopListening and then breaking every client connection by calling Disconnect.

StartListening Method (AzureRelayReceiver Component)

Starts listening for incoming connections.

Syntax

procedure StartListening();

Remarks

This method begins listening for incoming connections on the port specified by LocalPort. Once listening events will fire as new clients connect and data is transferred.

To stop listening for new connections call StopListening. To stop listening for new connections and disconnect all existing clients call Shutdown.

The following properties are applicable when calling this method:

• AccessKey (required)
• AccessKeyName (required)
• HybridConnection (required)
• NamespaceAddress (required)
• DefaultTimeout
• ForwardingHost
• ForwardingPort

StopListening Method (AzureRelayReceiver Component)

This method stops listening for new connections.

Syntax

procedure StopListening();

Remarks

This method stops listening for new connections. After being called, any new connection attempts will be rejected. Calling this method does not disconnect existing connections.

To stop listening and to disconnect all existing clients, call Shutdown instead.

Connected Event (AzureRelayReceiver Component)

This event is fired immediately after the WebSocket handshake completes (or fails).

Syntax

type TConnectedEvent = procedure (
  Sender: TObject;
  StatusCode: Integer;
  const Description: String
) of Object;

property OnConnected: TConnectedEvent read FOnConnected write FOnConnected;

Remarks

The Connected event will fire after the entire WebSocket connection and handshake process finishes (or fails). This consists of three steps: (1) the initial TCP connection (along with SSL negotiation, if used), (2) the HTTP "Upgrade" request, and (3) the 101 HTTP response.

If the connection is made normally, StatusCode is 0 and Description is 'OK'.

If the connection fails, StatusCode has the error code returned by the TCP/IP stack. Description contains a description of this code. The value of StatusCode is equal to the value of the error.

Note: Please refer to the Error Codes section for more information.

ConnectionConnected Event (AzureRelayReceiver Component)

Fired when a client has connected.

Syntax

type TConnectionConnectedEvent = procedure (
  Sender: TObject;
  ConnectionId: Integer
) of Object;

property OnConnectionConnected: TConnectionConnectedEvent read FOnConnectionConnected write FOnConnectionConnected;

Remarks

This event fires when a client has successfully established a WebSocket connection.

ConnectionId identifies the connection.

ConnectionDataIn Event (AzureRelayReceiver Component)

Fired when data is received.

Syntax

type TConnectionDataInEvent = procedure (
  Sender: TObject;
  ConnectionId: Integer;
  DataFormat: Integer;
  const Text: String;
  const TextB: TBytes;
  EOM: Boolean
) of Object;

property OnConnectionDataIn: TConnectionDataInEvent read FOnConnectionDataIn write FOnConnectionDataIn;

Remarks

The DataIn event provides the data received from the client identified by the ConnectionId parameter.

The incoming data are provided through the Text parameter.

The DataFormat parameter identifies the encoding (if any) of the data. Possible value are as follows:

The EOM parameter stands for End of Message. By default, the component will fire the DataIn event as data are received. Larger messages will be fragmented and will cause the event to fire multiple times. When EOM is True within the event, this indicates the current fragment is also the final fragment of the message. The component may also be configured to buffer the message internally until the complete message is received. To enable this, set BufferMessage to True.

The EOL parameter stands for End of Line. When LineMode is False, EOL will always be False. When LineMode is True, EOL will be True if the DataIn event fired because an EOL was received and will be False if the DataIn event fired because MaxLineLength was reached.

ConnectionDisconnected Event (AzureRelayReceiver Component)

Fired when a WebSocket connection is disconnected.

Syntax

type TConnectionDisconnectedEvent = procedure (
  Sender: TObject;
  ConnectionId: Integer;
  StatusCode: Integer;
  const Description: String
) of Object;

property OnConnectionDisconnected: TConnectionDisconnectedEvent read FOnConnectionDisconnected write FOnConnectionDisconnected;

Remarks

When the connection is closed the StatusCode parameter may be used to determine if the disconnect occurred normally or if there was an error condition. If the connection is closed normally the StatusCode will be 1000. The Description parameter will contain a textual description returned by the server. Common StatusCode values are:

ConnectionError Event (AzureRelayReceiver Component)

Information about errors during data delivery.

Syntax

type TConnectionErrorEvent = procedure (
  Sender: TObject;
  ConnectionId: Integer;
  ErrorCode: Integer;
  const Description: String
) of Object;

property OnConnectionError: TConnectionErrorEvent read FOnConnectionError write FOnConnectionError;

Remarks

The Error event is fired in case of exceptional conditions during message processing. Normally the component raises an exception.

ConnectionId contains an error code and Description contains a textual description of the error. For a list of valid error codes and their descriptions, please refer to the Error Codes section.

ErrorCode contains an error code and Description contains a textual description of the error. For a list of valid error codes and their descriptions, please refer to the Error Codes section.

ConnectionReadyToSend Event (AzureRelayReceiver Component)

Fired when the component is ready to send data.

Syntax

type TConnectionReadyToSendEvent = procedure (
  Sender: TObject;
  ConnectionId: Integer
) of Object;

property OnConnectionReadyToSend: TConnectionReadyToSendEvent read FOnConnectionReadyToSend write FOnConnectionReadyToSend;

Remarks

The ReadyToSend event indicates that the underlying TCP/IP subsystem is ready to accept data after a failed Send. The event is also fired immediately after a connection is established.

ConnectionRequest Event (AzureRelayReceiver Component)

Fires when a WebSocket connection is requested.

Syntax

type TConnectionRequestEvent = procedure (
  Sender: TObject;
  var Accept: Boolean;
  const RendezvousAddress: String;
  const Id: String;
  const ConnectHeaders: String;
  const SubProtocols: String;
  const Extensions: String;
  const Host: String;
  const RemoteAddress: String;
  RemotePort: Integer;
  var StatusCode: Integer;
  var StatusDescription: String
) of Object;

property OnConnectionRequest: TConnectionRequestEvent read FOnConnectionRequest write FOnConnectionRequest;

Remarks

This event fires when a client requests a connection. The parameters of this event may be used to determine whether to accept or reject the connection.

To accept a connection set Accept to True (default). To reject a connection set Accept to False and set StatusCode and StatusDescription.

Accept defines whether the connection request is accepted or rejected. The default value is True. Set this to False to reject the connection.

RendezvousAddress holds the rendezvous URL to which the connection specific websocket connection will be made. This is informational only.

Id holds the Id of the connection. If an Id was specified by the client it is present here, otherwise the Azure Relay Service generates a value. For instance: b3ac97ea-d0f0-4286-bf1d-d493a4a22c27_G23_G22.

ConnectHeaders contains a JSON object with the HTTP headers that have been supplied by the sender to the Azure Relay service. For instance:

"connectHeaders": {
	"Sec-WebSocket-Key": "wIdDlRBg\/J\/Hx12q6iFdUQ==",
	"Sec-WebSocket-Version": "13",
	"Origin": "null",
	"Connection": "Upgrade",
	"Upgrade": "websocket",
	"Accept-Encoding": "gzip, deflate",
	"Host": "nstest.servicebus.windows.net",
	"User-Agent": "IPWorks HTTP Component - www.nsoftware.com"
}

SubProtocols holds the subprotocols (application-level protocols layered over the WebSocket Protocol) sent by the client in the initial WebSocket connection request.

Extensions holds the WebSocket extensions sent by the client in the initial WebSocket connection request.

Host is the Host header value of the connected client.

RemoteAddress is the IP address of the connecting client.

RemotePort is the port used by the connecting client.

StatusCode is a 3 digit HTTP status code used when Accept is set to False. Set this to any 3 digit HTTP status code when rejecting a connection. For instance: 404.

StatusDescription should be set to the text description corresponding to the StatusCode value when rejecting a connection. For instance: Not Found.

ConnectionStatus Event (AzureRelayReceiver Component)

This event is fired to indicate changes in connection state.

Syntax

type TConnectionStatusEvent = procedure (
  Sender: TObject;
  const ConnectionEvent: String;
  StatusCode: Integer;
  const Description: String
) of Object;

property OnConnectionStatus: TConnectionStatusEvent read FOnConnectionStatus write FOnConnectionStatus;

Remarks

The ConnectionStatus event is fired when the connection state changes, such as completion of a firewall or proxy connection or completion of a security handshake.

The ConnectionEvent parameter indicates the type of connection event. Values may include the following:

Disconnected Event (AzureRelayReceiver Component)

Fired when a connection is closed.

Syntax

type TDisconnectedEvent = procedure (
  Sender: TObject;
  StatusCode: Integer;
  const Description: String
) of Object;

property OnDisconnected: TDisconnectedEvent read FOnDisconnected write FOnDisconnected;

Remarks

If the connection is broken normally, StatusCode is 0 and Description is 'OK'.

If the connection is broken for any other reason, StatusCode has the error code returned by the Transmission Control Protocol (TCP/IP) subsystem. Description contains a description of this code. The value of StatusCode is equal to the value of the TCP/IP error.

Please refer to the Error Codes section for more information.

Error Event (AzureRelayReceiver Component)

Fired when information is available about errors during data delivery.

Syntax

type TErrorEvent = procedure (
  Sender: TObject;
  ErrorCode: Integer;
  const Description: String
) of Object;

property OnError: TErrorEvent read FOnError write FOnError;

Remarks

The Error event is fired in case of exceptional conditions during message processing. Normally the component raises an exception.

The ErrorCode parameter contains an error code, and the Description parameter contains a textual description of the error. For a list of valid error codes and their descriptions, please refer to the Error Codes section.

Header Event (AzureRelayReceiver Component)

Fired every time a header line comes in.

Syntax

type THeaderEvent = procedure (
  Sender: TObject;
  const Field: String;
  const Value: String
) of Object;

property OnHeader: THeaderEvent read FOnHeader write FOnHeader;

Remarks

The Field parameter contains the name of the HTTP header (which is the same as it is delivered). The Value parameter contains the header contents.

If the header line being retrieved is a continuation header line, then the Field parameter contains '' (empty string).

HTTPRequest Event (AzureRelayReceiver Component)

Fires when an HTTP request is received.

Syntax

type THTTPRequestEvent = procedure (
  Sender: TObject;
  ConnectionId: Integer;
  const RendezvousAddress: String;
  const Id: String;
  const RequestHeaders: String;
  const RequestTarget: String;
  const RequestMethod: String;
  const Host: String;
  const RemoteAddress: String;
  RemotePort: Integer;
  const RequestData: String;
  const RequestDataB: TBytes
) of Object;

property OnHTTPRequest: THTTPRequestEvent read FOnHTTPRequest write FOnHTTPRequest;

Remarks

This event fires when an HTTP request is received. The parameters of this event describe the details of the HTTP request.

The ConnectionId value must be saved and used when calling SendHTTPResponse.

Parameter Descriptions

ConnectionId contains an identifier generated by the component to identify each connection. This identifier is unique to this connection.

RendezvousAddress holds the rendezvous URL to which the connection specific websocket connection may be made. This is for information only, no action needs to be taken based on this value. For instance: wss://g2-prod-by3-003-sb.servicebus.windows.net/$hc/hc1?sb-hc-action=request&sb-hc-id=e1df5efe-0988-450c-9512-f9f1d91b39a0_G2

Id holds the Id of the connection. If an Id was specified by the client it is present here, otherwise the Azure Relay service generates a value. For instance: 2d4acb89-7d15-4aeb-bcd5-66e031580a90_G21_G1.

RequestHeaders contains a JSON object containing the HTTP headers supplied to the Azure Relay service by the sender. Note that authorization values used to authenticate to the Azure Relay service, as well as all headers defined in RFC 7230 with the exception of Via are also stripped. For instance headers such as Content-Length are stripped by the relay and are not present in this value. For instance:

"requestHeaders": {
	"Accept-Encoding": "gzip, deflate",
	"Host": "nstest.servicebus.windows.net",
	"User-Agent": "IPWorks HTTP Component - www.nsoftware.com",
	"Via": "1.1 nstest.servicebus.windows.net"
}

RequestTarget is the request target including query string params, as defined in RFC 7230 section 5.3. For instance /hc1.

RequestMethod contains HTTP method sent in the request. For instance POST or GET.

Hostholds the Host header value of the connected client.

RemoteHost contains the IP address of the remote host that initiated the HTTP request (the client).

RemotePort contains the port used by the remote host to establish the connection.

RequestData holds the body of the HTTP request (if any).

Log Event (AzureRelayReceiver Component)

This event fires once for each log message.

Syntax

type TLogEvent = procedure (
  Sender: TObject;
  ConnectionId: Integer;
  LogLevel: Integer;
  const Message: String;
  const LogType: String
) of Object;

property OnLog: TLogEvent read FOnLog write FOnLog;

Remarks

This event fires once for each log message generated by the component. The verbosity is controlled by the LogLevel setting.

LogLevel indicates the level of message. Possible values are as follows:

The value 1 (Info) logs basic information including the URL, HTTP version, and connection status details.

The value 2 (Verbose) logs additional information about the initial HTTP request.

The value 3 (Debug) logs additional debug information (if available).

Message is the log entry.

LogType identifies the type of log entry. Possible values are as follows:

• "Info"
• "Error"
• "Verbose"
• "Debug"

Redirect Event (AzureRelayReceiver Component)

Fired when a redirection is received from the server.

Syntax

type TRedirectEvent = procedure (
  Sender: TObject;
  const Location: String;
  var Accept: Boolean
) of Object;

property OnRedirect: TRedirectEvent read FOnRedirect write FOnRedirect;

Remarks

This event is fired in cases in which the client can decide whether or not to continue with the redirection process. The Accept parameter is always True by default, but if you do not want to follow the redirection, Accept may be set to False, in which case the component raises an exception. Location is the location to which the client is being redirected. Further control over redirection is provided in the FollowRedirects property.

SSLServerAuthentication Event (AzureRelayReceiver Component)

Fired after the server presents its certificate to the client.

Syntax

type TSSLServerAuthenticationEvent = procedure (
  Sender: TObject;
  const CertEncoded: String;
  const CertEncodedB: TBytes;
  const CertSubject: String;
  const CertIssuer: String;
  const Status: String;
  var Accept: Boolean
) of Object;

property OnSSLServerAuthentication: TSSLServerAuthenticationEvent read FOnSSLServerAuthentication write FOnSSLServerAuthentication;

Remarks

During this event, the client can decide whether or not to continue with the connection process. The Accept parameter is a recommendation on whether to continue or close the connection. This is just a suggestion: application software must use its own logic to determine whether or not to continue.

When Accept is False, Status shows why the verification failed (otherwise, Status contains the string OK). If it is decided to continue, you can override and accept the certificate by setting the Accept parameter to True.

SSLStatus Event (AzureRelayReceiver Component)

Fired when secure connection progress messages are available.

Syntax

type TSSLStatusEvent = procedure (
  Sender: TObject;
  const Message: String
) of Object;

property OnSSLStatus: TSSLStatusEvent read FOnSSLStatus write FOnSSLStatus;

Remarks

The event is fired for informational and logging purposes only. This event tracks the progress of the connection.

AzureRelayConnection Type

A currently connected client.

Remarks

This type describes the connection of a client which is currently connected to the component. You may use the different fields of this type to manage the connection.

Fields

"connectHeaders": {
	"Sec-WebSocket-Key": "QocLBwK5J40Qp35L2duoBg==",
	"Sec-WebSocket-Version": "13",
	"Origin": "null",
	"Connection": "Upgrade",
	"Upgrade": "websocket",
	"Accept-Encoding": "gzip, deflate",
	"Host": "nstest.servicebus.windows.net",
	"User-Agent": "IPWorks HTTP Component - www.nsoftware.com"
}

Constructors

constructor Create();

Certificate Type

This is the digital certificate being used.

Remarks

This type describes the current digital certificate. The certificate may be a public or private key. The fields are used to identify or select certificates.

Fields

Constructors

>

constructor Create();

constructor Create(valEncoded: TBytes);

constructor Create(valStoreType: TipqCertStoreTypes; valStore: String; valStorePassword: String; valSubject: String);

constructor Create(valStoreType: TipqCertStoreTypes; valStore: TBytes; valStorePassword: String; valSubject: String);

Firewall Type

The firewall the component will connect through.

Remarks

When connecting through a firewall, this type is used to specify different properties of the firewall, such as the firewall Host and the FirewallType.

Fields

Constructors

constructor Create();

Proxy Type

The proxy the component will connect to.

Remarks

When connecting through a proxy, this type is used to specify different properties of the proxy, such as the Server and the AuthScheme.

Fields

Constructors

constructor Create();

constructor Create(valServer: String; valPort: Integer);

constructor Create(valServer: String; valPort: Integer; valUser: String; valPassword: String);

Config Settings (AzureRelayReceiver Component)

AzureRelayReceiver Config Settings

WebSocketServer Config Settings

TCPServer Config Settings

SSL Config Settings

-----BEGIN CERTIFICATE-----
MIIEKzCCAxOgAwIBAgIRANTET4LIkxdH6P+CFIiHvTowDQYJKoZIhvcNAQELBQAw
... Intermediate Cert ...
eWHV5OW1K53o/atv59sOiW5K3crjFhsBOd5Q+cJJnU+SWinPKtANXMht+EDvYY2w
F0I1XhM+pKj7FjDr+XNj
-----END CERTIFICATE-----
\r \n
-----BEGIN CERTIFICATE-----
MIIEFjCCAv6gAwIBAgIQetu1SMxpnENAnnOz1P+PtTANBgkqhkiG9w0BAQUFADBp
... Root Cert ...
d8q23djXZbVYiIfE9ebr4g3152BlVCHZ2GyPdjhIuLeH21VbT/dyEHHA
-----END CERTIFICATE-----

-----BEGIN CERTIFICATE-----
MIIEKzCCAxOgAwIBAgIRANTET4LIkxdH6P+CFIiHvTowDQYJKoZIhvcNAQELBQAw
... Intermediate Cert ...
eWHV5OW1K53o/atv59sOiW5K3crjFhsBOd5Q+cJJnU+SWinPKtANXMht+EDvYY2w
F0I1XhM+pKj7FjDr+XNj
-----END CERTIFICATE-----
\r \n
-----BEGIN CERTIFICATE-----
MIIEFjCCAv6gAwIBAgIQetu1SMxpnENAnnOz1P+PtTANBgkqhkiG9w0BAQUFADBp
... Root Cert ...
d8q23djXZbVYiIfE9ebr4g3152BlVCHZ2GyPdjhIuLeH21VbT/dyEHHA
-----END CERTIFICATE-----

-----BEGIN CERTIFICATE-----
MIIEKzCCAxOgAwIBAgIRANTET4LIkxdH6P+CFIiHvTowDQYJKoZIhvcNAQELBQAw
... Intermediate Cert...
eWHV5OW1K53o/atv59sOiW5K3crjFhsBOd5Q+cJJnU+SWinPKtANXMht+EDvYY2w
F0I1XhM+pKj7FjDr+XNj
-----END CERTIFICATE-----
\r \n
-----BEGIN CERTIFICATE-----
MIIEFjCCAv6gAwIBAgIQetu1SMxpnENAnnOz1P+PtTANBgkqhkiG9w0BAQUFADBp
... Root Cert...
d8q23djXZbVYiIfE9ebr4g3152BlVCHZ2GyPdjhIuLeH21VbT/dyEHHA
-----END CERTIFICATE-----

Trappable Errors (AzureRelayReceiver Component)

WebSocketServer Errors

TCPServer Errors

SSL Errors

TCP/IP Errors