chilkat.WebSocket

Controls whether Chilkat automatically answers an incoming Close control frame.

• When true, an incoming Close is answered automatically if the client did not already initiate the close. After a Close has been both received and sent, Chilkat closes the underlying connection.
• When false, the application can detect the received Close through CloseReceived or FrameOpcode and call SendClose itself.

The default is true.

Returns the UTF-8 reason text contained in the received Close control frame.

The value is empty when the peer supplied no reason or when no Close frame has been received. A reason is diagnostic text and should not be treated as a stable machine-readable error identifier; use CloseStatusCode for protocol-level handling.

true after a Close control frame has been received on the current WebSocket connection.

When CloseAutoRespond is false, use this property to determine whether the application needs to call SendClose to complete the closing handshake. The received status code and reason, if present, are available through CloseStatusCode and CloseReason.

Returns the status code contained in the received Close control frame.

Returns 0 when no Close frame has been received or when the received Close frame did not include a status code.

If set to a file path, this property logs the LastErrorText of each Chilkat method or property call to the specified file. This logging helps identify the context and history of Chilkat calls leading up to any crash or hang, aiding in debugging.

Enabling the VerboseLogging property provides more detailed information. This property is mainly used for debugging rare instances where a Chilkat method call causes a hang or crash, which should generally not happen.

Possible causes of hangs include:

• A timeout property set to 0, indicating an infinite timeout.
• A hang occurring within an event callback in the application code.
• An internal bug in the Chilkat code causing the hang.

true if the frame most recently delivered by ReadFrame had its WebSocket FIN bit set; otherwise false.

For a fragmented data message, continue reading while this property is false. The fragment with true completes the message. Unfragmented messages have true on their only frame.

Returns the number of payload bytes currently accumulated in the internal receive buffer.

The value can represent data from one frame or from multiple calls to ReadFrame, which is useful when receiving a fragmented message. The accumulated bytes remain available until retrieved by GetFrameData, GetFrameDataSb, or GetFrameDataBd.

Returns the symbolic opcode of the frame most recently delivered by ReadFrame.

Before any frame has been received, the value is the empty string. Ping or Pong frames handled internally by the auto-response/auto-consume options may not be returned as the current frame.

Returns the numeric opcode of the frame most recently delivered by ReadFrame.

Use FrameOpcode when a readable symbolic value is preferred.

Specifies the interval, in milliseconds, between AbortCheck event callbacks during supported blocking operations.

The default is 0, which disables periodic AbortCheck callbacks. Set a positive value when the application needs an opportunity to cancel a long-running send or receive operation.

Specifies the maximum number of milliseconds an active send or receive operation may remain stalled while waiting for additional network progress.

The default is 30000 milliseconds (30 seconds). This is an inactivity timeout, not a total limit on the duration of the operation. An operation may continue longer than this value as long as data continues to be transferred.

true when the underlying WebSocket network connection is currently open; otherwise false.

Provides HTML-formatted information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.

Provides plain text information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.

Provides XML-formatted information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.

Indicates the success or failure of the most recent method call: true means success, false means failure. This property remains unchanged by property setters or getters. This method is present to address challenges in checking for null or Nothing returns in certain programming languages. Note: This property does not apply to methods that return integer values or to boolean-returning methods where the boolean does not indicate success or failure.

true when a Ping frame has been received but no corresponding Pong has yet been sent.

This property is primarily useful when PingAutoRespond is false. Call SendPong as soon as practical; it automatically sends the received Ping payload in the Pong response.

Controls automatic handling of incoming Ping control frames.

• When true, Chilkat sends the required Pong automatically and ReadFrame consumes the Ping internally, continuing until another frame is available.
• When false, the Ping can be returned to the application. Check NeedSendPong and call SendPong as soon as practical.

The default is true.

Controls whether incoming Pong control frames are hidden from the application.

• When true, ReadFrame consumes Pong frames internally and continues reading until a non-Pong frame is available.
• When false, an incoming Pong can be returned normally with FrameOpcode equal to Pong.

The default is true. Check PongConsumed after ReadFrame to learn whether one or more Pong frames were consumed during that call.

true if the most recent call to ReadFrame internally consumed a Pong frame while PongAutoConsume was true.

The property is reset to false at the beginning of each ReadFrame call and set to true if a Pong is consumed during that call.

When ReadFrame returns false, this property categorizes the reason:

Use this value for programmatic branching and inspect LastErrorText for detailed diagnostics.

Contains a comma-separated list of rarely needed compatibility or platform options. The default is the empty string and should normally remain unchanged.

If set to true, then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. The default value is false. Verbose logging should only be used for debugging. The potentially large quantity of logged information may adversely affect peformance.

Version of the component/library, such as "10.1.0"

Adds the standard client opening-handshake headers to the Rest object supplied to UseConnection:

Upgrade: websocket
Connection: Upgrade
Sec-WebSocket-Key: ...
Sec-WebSocket-Version: 13

Sec-WebSocket-Key contains a newly generated client nonce used by the server to produce Sec-WebSocket-Accept.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Immediately closes the underlying network connection without completing the WebSocket closing handshake.

Use this method when the connection must be abandoned because of a fatal error, timeout, application shutdown, or an unresponsive peer.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Returns the bytes accumulated by successful calls to ReadFrame as a string, then clears the internal receive buffer.

This method is intended for WebSocket text-message data. For arbitrary binary payloads, use GetFrameDataBd to avoid interpreting binary bytes as text.

Returns the string, or nil, err on failure (or when nothing is found). The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Appends the bytes accumulated by successful calls to ReadFrame to binData, then clears the internal receive buffer.

Use this method for binary messages or whenever the exact received bytes must be preserved. Existing data in the destination BinData is retained because the received bytes are appended.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Appends the text represented by the bytes accumulated by successful calls to ReadFrame to sb, then clears the internal receive buffer.

Existing text in the destination StringBuilder is retained. This method is most appropriate for text-message data; use GetFrameDataBd for arbitrary binary payloads.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Checks whether bytes are currently waiting to be read from the underlying WebSocket connection.

Returns true when incoming data is available and false when no data is presently waiting.

Returns true or false: an answer, not a success flag.

Reads the next WebSocket frame from the connected server. On success, the method updates FrameOpcode, FrameOpcodeInt, FinalFrame, and FrameDataLen.

Frame payload bytes are added to an internal receive buffer. The buffer may therefore contain data accumulated by multiple calls to ReadFrame. Retrieve and clear it with GetFrameData, GetFrameDataSb, or GetFrameDataBd.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Sends a WebSocket Close control frame and begins or completes the closing handshake.

• If includeStatus is false, the Close frame contains no status code and statusCode and reason are ignored.
• If includeStatus is true, the frame contains statusCode followed by the UTF-8 bytes of reason.

The complete Close payload cannot exceed 125 bytes, leaving at most 123 bytes for the UTF-8 reason after the two-byte status code. Chilkat truncates an overlong reason. The API accepts status-code integers from 0 through 16383.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Sends one WebSocket text data frame containing stringToSend. WebSocket text data is UTF-8 on the wire.

• Set finalFrame to true when this frame completes the message.
• Set finalFrame to false when additional frames will follow as part of the same fragmented message.

For a normal unfragmented text message, call this method once with finalFrame set to true. For a fragmented message, call it repeatedly and set true only for the final fragment.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Sends one WebSocket binary data frame containing the current bytes in bdToSend.

• Set finalFrame to true when this frame completes the binary message.
• Set finalFrame to false when additional binary-message fragments will follow.

For an ordinary single-frame binary message, set finalFrame to true.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Sends one WebSocket text data frame containing the current contents of sbToSend.

• Set finalFrame to true when this frame completes the message.
• Set finalFrame to false when more fragments will follow.

For an ordinary single-frame text message, set finalFrame to true. WebSocket text data is UTF-8 on the wire.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Sends a WebSocket Ping control frame. If pingData is non-empty, its UTF-8 bytes are included as the Ping payload.

WebSocket control-frame payloads are limited to 125 bytes. If the UTF-8 representation exceeds this limit, Chilkat truncates it to 125 bytes.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Sends a WebSocket Pong control frame.

When a Ping has been received and has not yet been answered, this method automatically uses the previously received Ping payload as the Pong payload, as required for a Ping response.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Causes the calling WebSocket object to share the already-established WebSocket connection owned by ws.

This enables a bidirectional design in which separate WebSocket objects operate on the same connection—for example, one thread blocks in ReadFrame while another thread sends frames.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Associates this WebSocket object with an existing, connected Rest object and prepares it for a client-side WebSocket session.

The opening WebSocket handshake is an HTTP GET upgrade request. Using Rest for the underlying connection allows the application to configure TLS, proxies, authentication, custom request headers, IPv6, socket options, bandwidth limits, and other connection features before the upgrade is performed.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Validates the server's response to the WebSocket opening handshake sent through the associated Rest object.

Validation checks that the server accepted the HTTP upgrade and returned the expected WebSocket handshake response, including the value derived from the client's Sec-WebSocket-Key. If this method returns true, the connection has entered the WebSocket protocol and data or control frames may be exchanged.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Enables a method call to be aborted by triggering the AbortCheck event at intervals defined by the HeartbeatMs property. If HeartbeatMs is set to its default value of 0, no events will occur. For instance, set HeartbeatMs to 200 to trigger 5 AbortCheck events per second.

Example

local deadline = os.time() + 30                  -- give up after 30 seconds
web_socket.heartbeat_ms = 250                      -- call the handler 4 times per second
web_socket:set_event_handler({ abort_check = function() return os.time() > deadline end })

This provides the percentage completion for any method involving network communications or time-consuming processing, assuming the progress can be measured as a percentage. This event is triggered only when it's possible and logical to express the operation's progress as a percentage. The pctDone argument will range from 1 to 100. For methods that finish quickly, the number of PercentDone callbacks may vary, but the final callback will have pctDone equal to 100. For longer operations, callbacks will not exceed one per percentage point (e.g., 1, 2, 3, ..., 98, 99, 100).

The PercentDone callback also acts as an AbortCheck event. For fast methods where PercentDone fires, an AbortCheck event may not trigger since the PercentDone callback already provides an opportunity to abort. For longer operations, where time between PercentDone callbacks is extended, AbortCheck callbacks enable more responsive operation termination.

To abort the operation, set the abort output argument to true. This will cause the method to terminate and return a failure status or corresponding failure value.

Example

web_socket:set_event_handler({
    percent_done = function(pct_done)     -- 0 to 100
        print("Percent done: " .. pct_done)
        return false                       -- return true to abort the method in progress
    end,
})

This event callback provides tag name/value pairs that detail what occurs during a method call. To discover existing tag names, create code to handle the event, emit the pairs, and review them. Most tag names are self-explanatory.

Note: Some Chilkat methods don't fire any ProgressInfo events.

Example

web_socket:set_event_handler({
    progress_info = function(name, value) print(name .. ": " .. value) end,
})