STOMP Class

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A simple but powerful STOMP client implementation.

Syntax

class ipworksmq.STOMP

Remarks

The STOMP class provides an easy-to-use STOMP client implementation that supports STOMP versions 1.1 and 1.2. The class supports both plaintext and TLS-enabled connections over TCP.

Connecting

Connecting to a STOMP server is easy; in the simplest case just call the connect_to method, passing the server's hostname and port number.

When connecting to a STOMP server, the class sends information from the following properties, if populated:

• incoming_heartbeat
• outgoing_heartbeat
• user
• password

In addition to the above properties, the following configuration settings can be set before connecting (though in most cases this is not necessary):

• SupportedVersions: Controls which STOMP versions the class advertises support for.
• VirtualHost: Controls the virtual host to connect to. If left empty (default), the value from remote_host is used.

Subscriptions & Receiving Messages

When subscribe is called, it will return a subscription Id. To unsubscribe, pass this subscription Id to the unsubscribe method.

After subscribing to a message destination, any messages received will cause the on_message_in event to fire.

Basic Subscriptions Example stomp1.OnMessageIn += (s, e) => { Console.WriteLine("Received message from destination '" + e.Destination + "':"); Console.WriteLine(e.Data); }; string subId = stomp1.Subscribe("test/a/b", false); // Some time later... stomp1.Unsubscribe(subId);

Refer to subscribe, unsubscribe, and on_message_in for more information about subscriptions and receiving messages.

Sending Messages

To send messages, use the send_message and send_data methods. send_message is used to send messages with string payloads, while send_data is used to send messages with binary payloads.

Send String Message Example stomp1.SendMessage("test/a/b", "Hello, world!");

Send Binary Message Example byte[] fileContent = File.ReadAllBytes("C:\test\stuff.dat"); stomp1.SendData("test/a/b", fileContent);

Refer to send_message and send_data for more information about sending messages.

Using Transactions

STOMP transactions are used to group messages together for processing on the server. Messages sent as part of a transaction will not be delivered by the server until the transaction is committed. If the transaction is aborted, the server will discard the messages without attempting to deliver them.

Basic Transaction Example // Open a new transaction. stomp1.BeginTransaction("txn1"); // Set the Transaction property to make sure that messages are sent as part of the transaction. stomp1.Transaction = "txn1"; stomp1.SendMessage("test/a/b", "Hello, world!"); stomp1.SendMessage("test/a/b", "This is a test."); stomp1.SendMessage("test/a/b", "Another test!"); // At this point, none of the messages sent above would have been delivered to any clients // subscribed to the "test/a/b" destination yet, because the transaction is still open. // If we close and commit the transaction, the server will then deliver the messages to subscribers, // queue them, or process them in another manner; the behavior is server-dependent. stomp1.CommitTransaction("txn1"); // Or, the transaction can be aborted, in which case the server will discard the messages // without delivering them to the subscribers. //stomp1.AbortTransaction("txn1"); // Reset (or change) the Transaction property after committing or aborting a transaction // so that future messages are not associated with the previous transaction. stomp1.Transaction = "";

Refer to begin_transaction for more information about using transactions.

Property List

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

Method List

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

Event List

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

Config Settings

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

connected Property

Triggers a connection or disconnection.

Syntax

def get_connected() -> bool: ...
def set_connected(value: bool) -> None: ...

connected = property(get_connected, set_connected)

Default Value

FALSE

Remarks

This property triggers a connection or disconnection. Setting this property to True makes the class attempt to connect to the host identified by the remote_host property. If successful, after the connection is achieved the value of the property changes to True and the on_connected event is fired.

Setting this property to False closes the connection.

When connecting to a STOMP server, the class sends information from the following properties, if populated:

• incoming_heartbeat
• outgoing_heartbeat
• user
• password

In addition to the above properties, the following configuration settings can be set before connecting (though in most cases this is not necessary):

• SupportedVersions: Controls which STOMP versions the class advertises support for.
• VirtualHost: Controls the virtual host to connect to. If left empty (default), the value from remote_host is used.

content_type Property

The content type of the outgoing message.

Syntax

def get_content_type() -> str: ...
def set_content_type(value: str) -> None: ...

content_type = property(get_content_type, set_content_type)

Default Value

"text/plain"

Remarks

This property is used to specify the content type (MIME type) for outgoing messages sent using send_message. The default value is text/plain, which should be sufficient is most cases.

Note that this property is ignored for messages sent using send_data, as such messages do not have a content-type header added to them. The absence of a content-type header indicates to the server that the data should be treated as a binary blob.

firewall_auto_detect Property

This property tells the class whether or not to automatically detect and use firewall system settings, if available.

Syntax

def get_firewall_auto_detect() -> bool: ...
def set_firewall_auto_detect(value: bool) -> None: ...

firewall_auto_detect = property(get_firewall_auto_detect, set_firewall_auto_detect)

Default Value

FALSE

Remarks

This property tells the class whether or not to automatically detect and use firewall system settings, if available.

firewall_type Property

This property determines the type of firewall to connect through.

Syntax

def get_firewall_type() -> int: ...
def set_firewall_type(value: int) -> None: ...

firewall_type = property(get_firewall_type, set_firewall_type)

Default Value

0

Remarks

This property determines the type of firewall to connect through. The applicable values are as follows:

firewall_host Property

This property contains the name or IP address of firewall (optional).

Syntax

def get_firewall_host() -> str: ...
def set_firewall_host(value: str) -> None: ...

firewall_host = property(get_firewall_host, set_firewall_host)

Default Value

""

Remarks

This property contains the name or IP address of firewall (optional). If a firewall_host is given, the requested connections will be authenticated through the specified firewall when connecting.

If this property is set to a Domain Name, a DNS request is initiated. Upon successful termination of the request, this property is set to the corresponding address. If the search is not successful, the class fails with an error.

firewall_password Property

This property contains a password if authentication is to be used when connecting through the firewall.

Syntax

def get_firewall_password() -> str: ...
def set_firewall_password(value: str) -> None: ...

firewall_password = property(get_firewall_password, set_firewall_password)

Default Value

""

Remarks

This property contains a password if authentication is to be used when connecting through the firewall. If firewall_host is specified, the firewall_user and firewall_password properties are used to connect and authenticate to the given firewall. If the authentication fails, the class fails with an error.

firewall_port Property

This property contains the transmission control protocol (TCP) port for the firewall Host .

Syntax

def get_firewall_port() -> int: ...
def set_firewall_port(value: int) -> None: ...

firewall_port = property(get_firewall_port, set_firewall_port)

Default Value

0

Remarks

This property contains the transmission control protocol (TCP) port for the firewall firewall_host. See the description of the firewall_host property for details.

Note: This property is set automatically when firewall_type is set to a valid value. See the description of the firewall_type property for details.

firewall_user Property

This property contains a user name if authentication is to be used connecting through a firewall.

Syntax

def get_firewall_user() -> str: ...
def set_firewall_user(value: str) -> None: ...

firewall_user = property(get_firewall_user, set_firewall_user)

Default Value

""

Remarks

This property contains a user name if authentication is to be used connecting through a firewall. If the firewall_host is specified, this property and firewall_password properties are used to connect and authenticate to the given firewall. If the authentication fails, the class fails with an error.

header_count Property

The number of records in the Header arrays.

Syntax

def get_header_count() -> int: ...
def set_header_count(value: int) -> None: ...

header_count = property(get_header_count, set_header_count)

Default Value

0

Remarks

This property controls the size of the following arrays:

• header_key
• header_value

The array indices start at 0 and end at header_count - 1.

header_key Property

This header's key.

Syntax

def get_header_key(header_index: int) -> str: ...
def set_header_key(header_index: int, value: str) -> None: ...

Default Value

""

Remarks

This header's key.

This property holds this header's key (or name).

The header_index parameter specifies the index of the item in the array. The size of the array is controlled by the header_count property.

header_value Property

This header's value.

Syntax

def get_header_value(header_index: int) -> str: ...
def set_header_value(header_index: int, value: str) -> None: ...

Default Value

""

Remarks

This header's value.

This property holds this header's value.

The header_index parameter specifies the index of the item in the array. The size of the array is controlled by the header_count property.

incoming_heartbeat Property

Specifies the server-to-class heartbeat timing.

Syntax

def get_incoming_heartbeat() -> int: ...
def set_incoming_heartbeat(value: int) -> None: ...

incoming_heartbeat = property(get_incoming_heartbeat, set_incoming_heartbeat)

Default Value

0

Remarks

This property specifies the incoming heartbeat interval, which is the number of seconds without any server-to-class communication that the server will allow to elapse before sending the class a heartbeat (keepalive). If set to 0 (default), incoming heartbeats are disabled.

For information about outgoing (class-to-server) heartbeats; see the outgoing_heartbeat property.

Before Connecting

Before connecting, this property is used to specify the desired incoming heartbeat interval (in seconds). By default, this property is set to 0 (no heartbeat).

During the connection process, the incoming heartbeat interval requested by the class is compared to the minimum interval supported by the server, and the larger of the two values is selected. If one or both sides supply 0 as their value, then no server-to-class heartbeats will be sent.

After Connecting

After connecting, this property cannot be set. Instead, it reflects the incoming heartbeat interval agreed upon by the class and the server during the connection process.

As the incoming heartbeat interval negotiation notes above imply, it is possible that the agreed-upon incoming heartbeat interval may either be larger than what the class requested, or may be 0 (i.e., incoming heartbeats are disabled).

local_host Property

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

Syntax

def get_local_host() -> str: ...
def set_local_host(value: str) -> None: ...

local_host = property(get_local_host, set_local_host)

Default Value

""

Remarks

The local_host 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 multi-homed hosts (machines with more than one IP interface) setting LocalHost to the value of an interface will make the class initiate connections (or accept in the case of server classs) only through that interface.

If the class is connected, the local_host 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 multi-homed hosts (machines with more than one IP interface).

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

local_port Property

The TCP port in the local host where the class binds.

Syntax

def get_local_port() -> int: ...
def set_local_port(value: int) -> None: ...

local_port = property(get_local_port, set_local_port)

Default Value

0

Remarks

This property must be set before a connection is attempted. It instructs the class to bind to a specific port (or communication endpoint) in the local machine.

Setting this property to 0 (default) enables the system to choose an open port at random. The chosen port will be returned by the local_port property after the connection is established.

local_port cannot be changed once a connection is made. Any attempt to set this property when a connection is active will generate an error.

This property is useful when trying to connect to services that require a trusted port in the client side.

outgoing_heartbeat Property

Specifies the class-to-server heartbeat timing.

Syntax

def get_outgoing_heartbeat() -> int: ...
def set_outgoing_heartbeat(value: int) -> None: ...

outgoing_heartbeat = property(get_outgoing_heartbeat, set_outgoing_heartbeat)

Default Value

0

Remarks

This property specifies the outgoing heartbeat interval, which is the number of seconds without any class-to-server communication that the class will allow to elapse before sending the server a heartbeat (keepalive). If set to 0 (default), outgoing heartbeats are disabled.

For information about incoming (server-to-class) heartbeats; see the incoming_heartbeat property.

Before Connecting

Before connecting, this property is used to specify the minimum supported outgoing heartbeat interval (in seconds). By default, this property is set to 0 (no heartbeat).

During the connection process, the minimum outgoing heartbeat interval supported by the class is compared to the interval requested by the server, and the larger of the two values is selected. If one or both sides supply 0 as their value, then no class-to-server heartbeats will be sent.

After Connecting

After connecting, this property cannot be set. Instead, it reflects the outgoing heartbeat interval agreed upon by the class and the server during the connection process.

As the outgoing heartbeat interval negotiation notes above imply, it is possible that the agreed-upon outgoing heartbeat interval may either be larger than the class's supported minimum, or may be 0 (i.e., outgoing heartbeats are disabled).

parsed_header_count Property

The number of records in the ParsedHeader arrays.

Syntax

def get_parsed_header_count() -> int: ...

parsed_header_count = property(get_parsed_header_count, None)

Default Value

0

Remarks

This property controls the size of the following arrays:

• parsed_header_key
• parsed_header_value

The array indices start at 0 and end at parsed_header_count - 1.

This property is read-only.

parsed_header_key Property

This header's key.

Syntax

def get_parsed_header_key(parsed_header_index: int) -> str: ...

Default Value

""

Remarks

This header's key.

This property holds this header's key (or name).

The parsed_header_index parameter specifies the index of the item in the array. The size of the array is controlled by the parsed_header_count property.

This property is read-only.

parsed_header_value Property

This header's value.

Syntax

def get_parsed_header_value(parsed_header_index: int) -> str: ...

Default Value

""

Remarks

This header's value.

This property holds this header's value.

The parsed_header_index parameter specifies the index of the item in the array. The size of the array is controlled by the parsed_header_count property.

This property is read-only.

password Property

A password if authentication is to be used.

Syntax

def get_password() -> str: ...
def set_password(value: str) -> None: ...

password = property(get_password, set_password)

Default Value

""

Remarks

If this property is set when connecting, the class will send the password in the passcode header.

ready_to_send Property

Indicates whether the class is ready to send data.

Syntax

def get_ready_to_send() -> bool: ...

ready_to_send = property(get_ready_to_send, None)

Default Value

FALSE

Remarks

This property indicates that the underlying TCP/IP subsystem is ready to accept data. This is True after connecting to the remote host, and will become False if a call to send_data or send_message fails due to a WOULDBLOCK condition.

Once data can be sent again, the on_ready_to_send event will fire and this property will be True.

If a WOULDBLOCK error occurs while sending a message the class will automatically complete the transmission when sending is possible. No action needs to be taken to re-send the message. on_ready_to_send will fire after the class completes any partially sent messages.

This property is read-only.

remote_host Property

The address of the remote host. Domain names are resolved to IP addresses.

Syntax

def get_remote_host() -> str: ...
def set_remote_host(value: str) -> None: ...

remote_host = property(get_remote_host, set_remote_host)

Default Value

""

Remarks

This property specifies the IP address (IP number in dotted internet format) or Domain Name of the remote host. It is set before a connection is attempted and cannot be changed once a connection is established.

If this property is set to a Domain Name, a DNS request is initiated, and upon successful termination of the request, this property is set to the corresponding address. If the search is not successful, an error is returned.

If the class is configured to use a SOCKS firewall, the value assigned to this property may be preceded with an "*". If this is the case, the host name is passed to the firewall unresolved and the firewall performs the DNS resolution.

By default the class will connect in plaintext. To enable SSL set ssl_enabled to True.

remote_port Property

The port of the STOMP server (default is 61613). The default port for SSL is 61612.

Syntax

def get_remote_port() -> int: ...
def set_remote_port(value: int) -> None: ...

remote_port = property(get_remote_port, set_remote_port)

Default Value

61613

Remarks

This property specifies a service port on the remote host to connect to.

A valid port number (a value between 1 and 65535) is required for the connection to take place. The property must be set before a connection is attempted and cannot be changed once a connection is established. Any attempt to change this property while connected will fail with an error.

request_receipts Property

Whether the class should request that the server provide message receipts.

Syntax

def get_request_receipts() -> bool: ...
def set_request_receipts(value: bool) -> None: ...

request_receipts = property(get_request_receipts, set_request_receipts)

Default Value

FALSE

Remarks

This property is used to specify whether the class should request that the server send back confirmations (known as a "receipts" in STOMP terminology) when it receives messages from the class. This is done by adding a receipt header to the outgoing frame.

When this property is set to True, and a message is sent, the on_receipt_out event will fire immediately after the on_message_out event fires.

Note that, while this property only controls receipt requests for outgoing messages, the class is capable of requesting receipts for any outgoing frame type. Use this table to determine which API members control receipt request for each outgoing frame type (all are False by default):

Received Receipt Notes

When a receipt is received, the on_receipt_in event fires.

Note that receipts are cumulative, and a STOMP server is not required to send back discrete receipts for each frame it receives that has a receipt header. For example, if the class has sent four message frames with the following receipt header values (in chronological order):

1. SEND-3
2. SEND-4
3. SEND-5
4. SEND-6

ssl_accept_server_cert_encoded Property

This is the certificate (PEM/Base64 encoded).

Syntax

def get_ssl_accept_server_cert_encoded() -> bytes: ...
def set_ssl_accept_server_cert_encoded(value: bytes) -> None: ...

ssl_accept_server_cert_encoded = property(get_ssl_accept_server_cert_encoded, set_ssl_accept_server_cert_encoded)

Default Value

""

Remarks

This is the certificate (PEM/Base64 encoded). This property is used to assign a specific certificate. The ssl_accept_server_cert_store and ssl_accept_server_cert_subject properties also may be used to specify a certificate.

When ssl_accept_server_cert_encoded is set, a search is initiated in the current ssl_accept_server_cert_store for the private key of the certificate. If the key is found, ssl_accept_server_cert_subject is updated to reflect the full subject of the selected certificate; otherwise, ssl_accept_server_cert_subject is set to an empty string.

ssl_cert_encoded Property

This is the certificate (PEM/Base64 encoded).

Syntax

def get_ssl_cert_encoded() -> bytes: ...
def set_ssl_cert_encoded(value: bytes) -> None: ...

ssl_cert_encoded = property(get_ssl_cert_encoded, set_ssl_cert_encoded)

Default Value

""

Remarks

This is the certificate (PEM/Base64 encoded). This property is used to assign a specific certificate. The ssl_cert_store and ssl_cert_subject properties also may be used to specify a certificate.

When ssl_cert_encoded is set, a search is initiated in the current ssl_cert_store for the private key of the certificate. If the key is found, ssl_cert_subject is updated to reflect the full subject of the selected certificate; otherwise, ssl_cert_subject is set to an empty string.

ssl_cert_store Property

This is the name of the certificate store for the client certificate.

Syntax

def get_ssl_cert_store() -> bytes: ...
def set_ssl_cert_store(value: bytes) -> None: ...

ssl_cert_store = property(get_ssl_cert_store, set_ssl_cert_store)

Default Value

"MY"

Remarks

This is the name of the certificate store for the client certificate.

The ssl_cert_store_type property denotes the type of the certificate store specified by ssl_cert_store. If the store is password protected, specify the password in ssl_cert_store_password.

ssl_cert_store is used in conjunction with the ssl_cert_subject property to specify client certificates. If ssl_cert_store has a value, and ssl_cert_subject or ssl_cert_encoded is set, a search for a certificate is initiated. Please see the ssl_cert_subject property for details.

Designations of certificate stores are platform dependent.

The following designations are the most common User and Machine certificate stores in Windows:

When the certificate store type is PFXFile, this property must be set to the name of the file. When the type is PFXBlob, the property must be set to the binary contents of a PFX file (i.e., PKCS#12 certificate store).

ssl_cert_store_password Property

If the type of certificate store requires a password, this property is used to specify the password needed to open the certificate store.

Syntax

def get_ssl_cert_store_password() -> str: ...
def set_ssl_cert_store_password(value: str) -> None: ...

ssl_cert_store_password = property(get_ssl_cert_store_password, set_ssl_cert_store_password)

Default Value

""

Remarks

If the type of certificate store requires a password, this property is used to specify the password needed to open the certificate store.

ssl_cert_store_type Property

This is the type of certificate store for this certificate.

Syntax

def get_ssl_cert_store_type() -> int: ...
def set_ssl_cert_store_type(value: int) -> None: ...

ssl_cert_store_type = property(get_ssl_cert_store_type, set_ssl_cert_store_type)

Default Value

0

Remarks

This is the type of certificate store for this certificate.

The class supports both public and private keys in a variety of formats. When the cstAuto value is used, the class will automatically determine the type. This property can take one of the following values:

ssl_cert_subject Property

This is the subject of the certificate used for client authentication.

Syntax

def get_ssl_cert_subject() -> str: ...
def set_ssl_cert_subject(value: str) -> None: ...

ssl_cert_subject = property(get_ssl_cert_subject, set_ssl_cert_subject)

Default Value

""

Remarks

This is the subject of the certificate used for client authentication.

This property must be set after all other certificate properties are set. When this property is set, a search is performed in the current certificate store to locate a certificate with a matching subject.

If a matching certificate is found, the property is set to the full subject of the matching certificate.

If an exact match is not found, the store is searched for subjects containing the value of the property.

If a match is still not found, the property is set to an empty string, and no certificate is selected.

The special value "*" picks a random certificate in the certificate store.

The certificate subject is a comma-separated list of distinguished name fields and values. For instance, "CN=www.server.com, OU=test, C=US, E=support@nsoftware.com". Common fields and their meanings are as follows:

If a field value contains a comma, it must be quoted.

ssl_enabled Property

Whether TLS/SSL is enabled.

Syntax

def get_ssl_enabled() -> bool: ...
def set_ssl_enabled(value: bool) -> None: ...

ssl_enabled = property(get_ssl_enabled, set_ssl_enabled)

Default Value

FALSE

Remarks

This setting specifies whether TLS/SSL is enabled in the class. When False (default) the class operates in plaintext mode. When True TLS/SSL is enabled.

TLS/SSL may also be enabled by setting ssl_start_mode. Setting ssl_start_mode will automatically update this property value.

ssl_provider Property

This specifies the SSL/TLS implementation to use.

Syntax

def get_ssl_provider() -> int: ...
def set_ssl_provider(value: int) -> None: ...

ssl_provider = property(get_ssl_provider, set_ssl_provider)

Default Value

0

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 class 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:

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

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

ssl_server_cert_encoded Property

This is the certificate (PEM/Base64 encoded).

Syntax

def get_ssl_server_cert_encoded() -> bytes: ...

ssl_server_cert_encoded = property(get_ssl_server_cert_encoded, None)

Default Value

""

Remarks

This is the certificate (PEM/Base64 encoded). This property is used to assign a specific certificate. The ssl_server_cert_store and ssl_server_cert_subject properties also may be used to specify a certificate.

When ssl_server_cert_encoded is set, a search is initiated in the current ssl_server_cert_store for the private key of the certificate. If the key is found, ssl_server_cert_subject is updated to reflect the full subject of the selected certificate; otherwise, ssl_server_cert_subject is set to an empty string.

This property is read-only.

subscription_count Property

The number of records in the Subscription arrays.

Syntax

def get_subscription_count() -> int: ...

subscription_count = property(get_subscription_count, None)

Default Value

0

Remarks

This property controls the size of the following arrays:

• subscription_destination
• subscription_id

The array indices start at 0 and end at subscription_count - 1.

This property is read-only.

subscription_destination Property

The destination on the server that this subscription is associated with.

Syntax

def get_subscription_destination(subscription_index: int) -> str: ...

Default Value

""

Remarks

The destination on the server that this subscription is associated with.

This property reflects the destination on the server that this subscription is associated with.

The subscription_index parameter specifies the index of the item in the array. The size of the array is controlled by the subscription_count property.

This property is read-only.

subscription_id Property

This subscription's unique Id.

Syntax

def get_subscription_id(subscription_index: int) -> str: ...

Default Value

""

Remarks

This subscription's unique Id.

This property reflects the unique Id of this subscription.

The subscription_index parameter specifies the index of the item in the array. The size of the array is controlled by the subscription_count property.

This property is read-only.

timeout Property

A timeout for the class.

Syntax

def get_timeout() -> int: ...
def set_timeout(value: int) -> None: ...

timeout = property(get_timeout, set_timeout)

Default Value

60

Remarks

If the timeout property is set to 0, all operations return immediately, potentially failing with a WOULDBLOCK error if data cannot be sent immediately.

If timeout is set to a positive value, data is sent in a blocking manner and the class will wait for the operation to complete before returning control. The class will handle any potential WOULDBLOCK errors internally and automatically retry the operation for a maximum of timeout seconds.

The class will use do_events to enter an efficient wait loop during any potential waiting period, making sure that all system events are processed immediately as they arrive. This ensures that the host application does not "freeze" and remains responsive.

If timeout expires, and the operation is not yet complete, the class fails with an error.

Please note that by default, all timeouts are inactivity timeouts, i.e. the timeout period is extended by timeout seconds when any amount of data is successfully sent or received.

The default value for the timeout property is 60 seconds.

transaction_id Property

Specifies the Id of the transaction that outgoing messages are associated with.

Syntax

def get_transaction_id() -> str: ...
def set_transaction_id(value: str) -> None: ...

transaction_id = property(get_transaction_id, set_transaction_id)

Default Value

""

Remarks

This property, if not empty, is used to specify which transaction outgoing messages sent using send_message or send_data are associated with.

This property must either be empty, or set to the Id of a currently open transaction. The OpenTransactions configuration setting can be queried at any time to retrieve a comma-separated list of currently open transactions' Ids.

Note that this property only affects outgoing messages. It is also possible to send a message acknowledgment as part of a transaction by setting the AckTransactionId configuration setting during the on_message_in event handler.

Refer to begin_transaction for more information about transactions.

user Property

A username if authentication is to be used.

Syntax

def get_user() -> str: ...
def set_user(value: str) -> None: ...

user = property(get_user, set_user)

Default Value

""

Remarks

If this property is set when connecting, the class will send the user in the login header.

abort_transaction Method

Aborts an existing transaction.

Syntax

def abort_transaction(id: str) -> None: ...

Remarks

This method aborts a transaction previously started with begin_transaction. Id identifies the transaction to abort.

The OpenTransactions configuration setting can be queried to obtain a list of currently-open transactions.

Refer to begin_transaction for more information about transactions.

add_header Method

Adds a custom header to send with outgoing messages.

Syntax

def add_header(key: str, value: str) -> None: ...

Remarks

This method is used to add user-defined headers to the list of headers held by the Header* properties.

When send_message or send_data is called, all headers in the Header* properties are added to the outgoing message.

Note that the STOMP specification defines a number of standard headers necessary for implementing the STOMP protocol. When constructing an outgoing message, the class silently ignores any user-defined headers that are already set by the class.

begin_transaction Method

Begins a new transaction.

Syntax

def begin_transaction(id: str) -> None: ...

Remarks

This method begins a new transaction using the specified Id, which must be unique. There is no limit to how many transactions may be open at any given time.

A transaction is a group of messages and message acknowledgments which are all processed atomically when the transaction is committed or aborted.

Messages sent in a transaction will not be delivered to clients subscribed to the messages' destinations until the transaction is committed.

Since it is possible for multiple transactions to be open at any given time, the transaction_id property is used to specify which transaction (if any) messages should be sent in. Similarly, message acknowledgments can be sent in a transaction by setting the AckTransactionId configuration setting during the on_message_in event handler.

The OpenTransactions configuration setting can be queried at any time to retrieve a comma-separated list of currently open transactions' Ids.

Basic Transaction Example // Open a new transaction. stomp1.BeginTransaction("txn1"); // Set the Transaction property to make sure that messages are sent as part of the transaction. stomp1.Transaction = "txn1"; stomp1.SendMessage("test/a/b", "Hello, world!"); stomp1.SendMessage("test/a/b", "This is a test."); stomp1.SendMessage("test/a/b", "Another test!"); // At this point, none of the messages sent above would have been delivered to any clients // subscribed to the "test/a/b" destination yet, because the transaction is still open. // If we close and commit the transaction, the server will then deliver the messages to subscribers, // queue them, or process them in another manner; the behavior is server-dependent. stomp1.CommitTransaction("txn1"); // Or, the transaction can be aborted, in which case the server will discard the messages // without delivering them to the subscribers. //stomp1.AbortTransaction("txn1"); // Reset (or change) the Transaction property after committing or aborting a transaction // so that future messages are not associated with the previous transaction. stomp1.Transaction = "";

commit_transaction Method

Commits an existing transaction.

Syntax

def commit_transaction(id: str) -> None: ...

Remarks

This method commits a transaction previously started with begin_transaction. Id identifies the transaction to commit.

The OpenTransactions configuration setting can be queried to obtain a list of currently-open transactions.

Refer to begin_transaction for more information about transactions.

config Method

Sets or retrieves a configuration setting.

Syntax

def config(configuration_string: str) -> str: ...

Remarks

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

These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the class, 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.

connect Method

Connects to the remote host.

Syntax

def connect() -> None: ...

Remarks

This method connects to the remote host, specified by remote_host and remote_port. Calling this method is equivalent to setting the connected property to True.

By default the class will connect in plaintext. To enable SSL set ssl_enabled to True.

When connecting to a STOMP server, the class sends information from the following properties, if populated:

• incoming_heartbeat
• outgoing_heartbeat
• user
• password

In addition to the above properties, the following configuration settings can be set before connecting (though in most cases this is not necessary):

• SupportedVersions: Controls which STOMP versions the class advertises support for.
• VirtualHost: Controls the virtual host to connect to. If left empty (default), the value from remote_host is used.

connect_to Method

Connects to the remote host.

Syntax

def connect_to(host: str, port: int) -> None: ...

Remarks

This method connects to the remote host specified by the Host and Port parameters. Calling this method is equivalent to setting the remote_host property to Host, setting remote_port to Port, and then setting the connected property to True.

By default the class will connect in plaintext. To enable SSL set ssl_enabled to True.

When connecting to a STOMP server, the class sends information from the following properties, if populated:

• incoming_heartbeat
• outgoing_heartbeat
• user
• password

In addition to the above properties, the following configuration settings can be set before connecting (though in most cases this is not necessary):

• SupportedVersions: Controls which STOMP versions the class advertises support for.
• VirtualHost: Controls the virtual host to connect to. If left empty (default), the value from remote_host is used.

disconnect Method

This method disconnects from the remote host.

Syntax

def disconnect() -> None: ...

Remarks

This method disconnects from the remote host. Calling this method is equivalent to setting the connected property to False.

do_events Method

Processes events from the internal message queue.

Syntax

def do_events() -> None: ...

Remarks

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

interrupt Method

Interrupt the current action and disconnects from the remote host.

Syntax

def interrupt() -> None: ...

Remarks

This method will interrupt the current method (if applicable) and cause the class to disconnect from the remote host.

reset Method

Reset the class.

Syntax

def reset() -> None: ...

Remarks

This method will reset the class's properties to their default values.

reset_headers Method

Clear the user-defined headers collection.

Syntax

def reset_headers() -> None: ...

Remarks

This method clears the Header* properties.

send_data Method

Publishes a message with a raw data payload.

Syntax

def send_data(destination: str, data: bytes) -> None: ...

Remarks

This method publishes a STOMP message with a raw data payload to the specified Destination. The on_message_out event will fire after the message has been sent.

The STOMP specification does not place any restrictions on Destination names. Instead, each STOMP server is free to define its own requirements for, and/or interpretations of, a Destination name; for example, a server might prohibit certain characters, require a specific format, or interpret some patterns in a special manner. Be sure to consult the documentation for your STOMP server to determine how to build proper Destination names.

In addition to the payload, the outgoing messages will include:

• All user-defined headers held by the Header* properties.
• If the transaction_id property is populated, the transaction Id that it specifies (which associates the message with that transaction).

If request_receipts is enabled when this method is called, the class will request that the server send back a receipt to confirm it has received the message. Refer to request_receipts for more information.

Note that no content type is defined for raw data payload messages; so the content_type property is ignored by this method.

Send String Message Example stomp1.SendMessage("test/a/b", "Hello, world!");

Send Binary Message Example byte[] fileContent = File.ReadAllBytes("C:\test\stuff.dat"); stomp1.SendData("test/a/b", fileContent);

send_message Method

Publishes a message with a string payload.

Syntax

def send_message(destination: str, message: str) -> None: ...

Remarks

This method publishes a STOMP message with a string payload to the specified Destination. The on_message_out event will fire after the message has been sent.

The content_type property can be used to specify the content type of the payload. By default, content_type is set to text/plain.

The STOMP specification does not place any restrictions on Destination names. Instead, each STOMP server is free to define its own requirements for, and/or interpretations of, a Destination name; for example, a server might prohibit certain characters, require a specific format, or interpret some patterns in a special manner. Be sure to consult the documentation for your STOMP server to determine how to build proper Destination names.

In addition to the payload, the outgoing messages will include:

• All user-defined headers held by the Header* properties.
• If the transaction_id property is populated, the transaction Id that it specifies (which associates the message with that transaction).

If request_receipts is enabled when this method is called, the class will request that the server send back a receipt to confirm it has received the message. Refer to request_receipts for more information.

Send String Message Example stomp1.SendMessage("test/a/b", "Hello, world!");

Send Binary Message Example byte[] fileContent = File.ReadAllBytes("C:\test\stuff.dat"); stomp1.SendData("test/a/b", fileContent);

subscribe Method

Subscribes to a message destination on the server.

Syntax

def subscribe(destination: str, require_acks: bool) -> str: ...

Remarks

This method is used to subscribe to the specified message Destination on the server. The Id of the subscription is returned.

Once subscribed, the on_subscribed event will fire and an item will be added to the Subscription* properties. The on_message_in event will fire anytime a message is received for any subscription.

The STOMP specification does not place any restrictions on Destination names. Instead, each STOMP server is free to define its own requirements for, and/or interpretations of, a Destination name; for example, a server might prohibit certain characters, require a specific format, or interpret some patterns in a special manner. Be sure to consult the documentation for your STOMP server to determine how to build proper Destination names.

If the RequireAcks parameter is set to True, the server will expect the class to send it a message acknowledgment for each message it delivers as part of this subscription. (Refer to the on_message_in event for more information about sending message acknowledgments).

Basic Subscriptions Example stomp1.OnMessageIn += (s, e) => { Console.WriteLine("Received message from destination '" + e.Destination + "':"); Console.WriteLine(e.Data); }; string subId = stomp1.Subscribe("test/a/b", false); // Some time later... stomp1.Unsubscribe(subId);

unsubscribe Method

Removes an existing subscription.

Syntax

def unsubscribe(id: str) -> None: ...

Remarks

This method removes an existing subscription identified by the given Id, unsubscribing the class from the destination associated with the subscription.

Once unsubscribed, the relevant item will be removed from the Subscription* properties and the on_unsubscribed event will fire.

Basic Subscriptions Example stomp1.OnMessageIn += (s, e) => { Console.WriteLine("Received message from destination '" + e.Destination + "':"); Console.WriteLine(e.Data); }; string subId = stomp1.Subscribe("test/a/b", false); // Some time later... stomp1.Unsubscribe(subId);

on_connected Event

This event is fired immediately after a connection completes (or fails).

Syntax

class STOMPConnectedEventParams(object):
  @property
  def status_code() -> int: ...

  @property
  def description() -> str: ...

# In class STOMP:
@property
def on_connected() -> Callable[[STOMPConnectedEventParams], None]: ...
@on_connected.setter
def on_connected(event_hook: Callable[[STOMPConnectedEventParams], None]) -> None: ...

Remarks

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 Transmission Control Protocol (TCP)/IP stack. Description contains a description of this code. The value of StatusCode is equal to the value of the error.

Please refer to the Error Codes section for more information.

on_connection_status Event

This event is fired to indicate changes in the connection state.

Syntax

class STOMPConnectionStatusEventParams(object):
  @property
  def connection_event() -> str: ...

  @property
  def status_code() -> int: ...

  @property
  def description() -> str: ...

# In class STOMP:
@property
def on_connection_status() -> Callable[[STOMPConnectionStatusEventParams], None]: ...
@on_connection_status.setter
def on_connection_status(event_hook: Callable[[STOMPConnectionStatusEventParams], None]) -> None: ...

Remarks

The on_connection_status event is fired when the connection state changes: for example, 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:

on_disconnected Event

This event is fired when a connection is closed.

Syntax

class STOMPDisconnectedEventParams(object):
  @property
  def status_code() -> int: ...

  @property
  def description() -> str: ...

# In class STOMP:
@property
def on_disconnected() -> Callable[[STOMPDisconnectedEventParams], None]: ...
@on_disconnected.setter
def on_disconnected(event_hook: Callable[[STOMPDisconnectedEventParams], None]) -> None: ...

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.

on_error Event

Fired when a class or protocol error occurs.

Syntax

class STOMPErrorEventParams(object):
  @property
  def error_code() -> int: ...

  @property
  def description() -> str: ...

  @property
  def data() -> bytes: ...

# In class STOMP:
@property
def on_error() -> Callable[[STOMPErrorEventParams], None]: ...
@on_error.setter
def on_error(event_hook: Callable[[STOMPErrorEventParams], None]) -> None: ...

Remarks

The on_error event is fired in case of exceptional conditions during message processing. Normally the class fails with an error.

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.

STOMP Protocol Errors

When this occurs, ErrorCode will be 600, Description will reflect the value of the ERROR frame's message header, and Data will contain the body of the ERROR frame (if one is present).

The ErrorHeaders configuration setting will also be populated with the raw headers from the ERROR frame for the duration of the on_error event handler.

on_log Event

Fired once for each log message.

Syntax

class STOMPLogEventParams(object):
  @property
  def log_level() -> int: ...

  @property
  def message() -> str: ...

  @property
  def log_type() -> str: ...

# In class STOMP:
@property
def on_log() -> Callable[[STOMPLogEventParams], None]: ...
@on_log.setter
def on_log(event_hook: Callable[[STOMPLogEventParams], None]) -> None: ...

Remarks

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

LogLevel indicates the level of the Message. Possible values are:

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

• Info: General information about the class.
• Acknowledgment: Information about outgoing message acknowledgments.
• Frame: Frame content logging.

on_message_in Event

Fired when a message has been received.

Syntax

class STOMPMessageInEventParams(object):
  @property
  def message_id() -> str: ...

  @property
  def subscription_id() -> str: ...

  @property
  def destination() -> str: ...

  @property
  def data() -> bytes: ...

  @property
  def content_type() -> str: ...

  @property
  def ack() -> bool: ...
  @ack.setter
  def ack(value) -> None: ...

# In class STOMP:
@property
def on_message_in() -> Callable[[STOMPMessageInEventParams], None]: ...
@on_message_in.setter
def on_message_in(event_hook: Callable[[STOMPMessageInEventParams], None]) -> None: ...

Remarks

This events fires whenever the class has received a message.

In addition to the message details exposed by the event parameters, the ParsedHeader* properties are populated with the headers parsed from the message. When the on_message_in event handler exits, the parsed headers are cleared. The following parameters are available within this event:

• MessageId: The unique Id of the message.
• SubscriptionId: The subscription Id the message is associated with.
• Destination: The message destination on the server which the message originated from.
• Data: The message's payload.
• ContentType: The content type of the message (may be empty).
• Ack: Set to True or False to control whether the class should send back a positive (True, default) or negative (False) message acknowledgment.

Message acknowledgments are only sent back to the server for messages which require them. A positive acknowledgment indicates that the message has been accepted, while a negative acknowledgment represents that the message has been rejected.

The following two configuration settings are also relevant in the context of sending back message acknowledgments for incoming messages:

• The AckTransactionId configuration setting, if not empty, specifies a transaction Id to associate the message acknowledgment with. It can only be set during the on_message_in event handler, and will be reset when the event handler ends.
• The RequestAckReceipts configuration setting controls whether the class will request that the server confirm receipt of the message acknowledgment. It is False by default, and can be set at any time.

on_message_out Event

Fired after a message has been sent.

Syntax

class STOMPMessageOutEventParams(object):
  @property
  def destination() -> str: ...

  @property
  def data() -> bytes: ...

  @property
  def content_type() -> str: ...

# In class STOMP:
@property
def on_message_out() -> Callable[[STOMPMessageOutEventParams], None]: ...
@on_message_out.setter
def on_message_out(event_hook: Callable[[STOMPMessageOutEventParams], None]) -> None: ...

Remarks

This event fires after a message has been sent using either send_message or send_data. The following parameters are available within this event:

• Destination: The destination the message was sent to.
• Data: The message's payload.
• ContentType: The content type of the message (always empty for messages sent with send_data).

on_ready_to_send Event

Fired when the class is ready to send data.

Syntax

class STOMPReadyToSendEventParams(object):
# In class STOMP:
@property
def on_ready_to_send() -> Callable[[STOMPReadyToSendEventParams], None]: ...
@on_ready_to_send.setter
def on_ready_to_send(event_hook: Callable[[STOMPReadyToSendEventParams], None]) -> None: ...

Remarks

The on_ready_to_send event indicates that the underlying TCP/IP subsystem is ready to accept data after a call to send_data or send_message fails due to a WOULDBLOCK condition. The event is also fired immediately after a connection to the remote host is established.

on_receipt_in Event

Fires when the class receives a receipt from the server.

Syntax

class STOMPReceiptInEventParams(object):
  @property
  def receipt_id() -> str: ...

# In class STOMP:
@property
def on_receipt_in() -> Callable[[STOMPReceiptInEventParams], None]: ...
@on_receipt_in.setter
def on_receipt_in(event_hook: Callable[[STOMPReceiptInEventParams], None]) -> None: ...

Remarks

This event fires anytime the class receives a receipt (that is, a confirmation that the server has received one or more frames) from the server. The ReceiptId parameter reflects the value of the receipt-id header in the incoming RECEIPT frame.

Note that receipts are cumulative, and a STOMP server is not required to send back discrete receipts for each frame it receives that has a receipt header. For example, if the class has sent four message frames with the following receipt header values (in chronological order):

1. SEND-3
2. SEND-4
3. SEND-5
4. SEND-6

Refer to request_receipts for more information about receipts.

on_receipt_out Event

Fires when the class sends a STOMP frame that includes a 'receipt' header.

Syntax

class STOMPReceiptOutEventParams(object):
  @property
  def receipt_id() -> str: ...

# In class STOMP:
@property
def on_receipt_out() -> Callable[[STOMPReceiptOutEventParams], None]: ...
@on_receipt_out.setter
def on_receipt_out(event_hook: Callable[[STOMPReceiptOutEventParams], None]) -> None: ...

Remarks

This event fires anytime the class sends any STOMP frame that includes a receipt header on it. The ReceiptId parameter reflects the value of the receipt header.

Having a receipt header on an outgoing frame indicates to the server that it should send back a receipt to confirm that it has received the frame (though it is not required to do so immediately; see on_receipt_in for details). Anytime the server sends back a receipt, the on_receipt_in event will fire.

Refer to request_receipts for more information about receipts.

on_ssl_server_authentication Event

Fired after the server presents its certificate to the client.

Syntax

class STOMPSSLServerAuthenticationEventParams(object):
  @property
  def cert_encoded() -> bytes: ...

  @property
  def cert_subject() -> str: ...

  @property
  def cert_issuer() -> str: ...

  @property
  def status() -> str: ...

  @property
  def accept() -> bool: ...
  @accept.setter
  def accept(value) -> None: ...

# In class STOMP:
@property
def on_ssl_server_authentication() -> Callable[[STOMPSSLServerAuthenticationEventParams], None]: ...
@on_ssl_server_authentication.setter
def on_ssl_server_authentication(event_hook: Callable[[STOMPSSLServerAuthenticationEventParams], None]) -> None: ...

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.

on_ssl_status Event

Fired when secure connection progress messages are available.

Syntax

class STOMPSSLStatusEventParams(object):
  @property
  def message() -> str: ...

# In class STOMP:
@property
def on_ssl_status() -> Callable[[STOMPSSLStatusEventParams], None]: ...
@on_ssl_status.setter
def on_ssl_status(event_hook: Callable[[STOMPSSLStatusEventParams], None]) -> None: ...

Remarks

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

on_subscribed Event

Fired when the class has subscribed to a message destination on the server.

Syntax

class STOMPSubscribedEventParams(object):
  @property
  def id() -> str: ...

  @property
  def destination() -> str: ...

  @property
  def require_acks() -> bool: ...

# In class STOMP:
@property
def on_subscribed() -> Callable[[STOMPSubscribedEventParams], None]: ...
@on_subscribed.setter
def on_subscribed(event_hook: Callable[[STOMPSubscribedEventParams], None]) -> None: ...

Remarks

This event fires each time the class has subscribed to a message destination on the server. The following parameters are available within this event:

• Id: The Id used to identify the subscription.
• Destination: The message destination on the server which the subscription is associated with.
• RequireAcks: Whether messages the class receives as a result of the subscription will require acknowledgments to be sent back to the server.

on_unsubscribed Event

Fired when the class has unsubscribed from a message destination on the server.

Syntax

class STOMPUnsubscribedEventParams(object):
  @property
  def id() -> str: ...

  @property
  def destination() -> str: ...

# In class STOMP:
@property
def on_unsubscribed() -> Callable[[STOMPUnsubscribedEventParams], None]: ...
@on_unsubscribed.setter
def on_unsubscribed(event_hook: Callable[[STOMPUnsubscribedEventParams], None]) -> None: ...

Remarks

This event fires each time the class has unsubscribed from a message destination on the server. The following parameters are available within this event:

• Id: The Id that was used to identify the subscription.
• Destination: The message destination on the server which the subscription was associated with.

STOMP Config Settings

STOMP Config Settings

TCPClient Config Settings

SSL Config Settings

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

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

Socket Config Settings

STOMP Errors

STOMP Errors

TCPClient Errors

SSL Errors

TCP/IP Errors