Message

class Message(content: RecordDict, dst_node_id: int, message_type: str, *, ttl: float | None = None, group_id: str | None = None)

class Message(content: RecordDict, *, reply_to: Message, ttl: float | None = None)

class Message(error: Error, *, reply_to: Message, ttl: float | None = None)

Bases: object

Represents a message exchanged between ClientApp and ServerApp.

This class encapsulates the payload and metadata necessary for communication between a ClientApp and a ServerApp.

Parameters:

• content (Optional[RecordDict] (default: None)) – Holds records either sent by another entity (e.g. sent by the server-side logic to a client, or vice-versa) or that will be sent to it.

• error (Optional[Error] (default: None)) – A dataclass that captures information about an error that took place when processing another message.

• dst_node_id (Optional[int] (default: None)) – An identifier for the node receiving this message.

• message_type (Optional[str] (default: None)) – A string that encodes the action to be executed on the receiving end.

• ttl (Optional[float] (default: None)) – Time-to-live (TTL) for this message in seconds. If None (default), the TTL is set to 43,200 seconds (12 hours).

• group_id (Optional[str] (default: None)) – An identifier for grouping messages. In some settings, this is used as the FL round.

• reply_to (Optional[Message] (default: None)) – The instruction message to which this message is a reply. This message does not retain the original message’s content but derives its metadata from it.

Methods

create_error_reply(error[, ttl])	Construct a reply message indicating an error happened.
create_reply(content[, ttl])	Create a reply to this message with specified content and TTL.
has_content()	Return True if message has content, else False.
has_error()	Return True if message has an error, else False.

Attributes

content	The content of this message.
error	Error captured by this message.
metadata	A dataclass including information about the message to be executed.

property content: RecordDict

The content of this message.

create_error_reply(error: Error, ttl: float | None = None) → Message

Construct a reply message indicating an error happened.

Parameters:

• error (Error) – The error that was encountered.

• ttl (Optional[float] (default: None)) –

  Time-to-live for this message in seconds. If unset, it will be set based on the remaining time for the received message before it expires. This follows the equation:

  ttl = msg.meta.ttl - (reply.meta.created_at - msg.meta.created_at)

Returns:

message – A Message containing only the relevant error and metadata.

Return type:

Message

create_reply(content: RecordDict, ttl: float | None = None) → Message

Create a reply to this message with specified content and TTL.

The method generates a new Message as a reply to this message. It inherits ‘run_id’, ‘src_node_id’, ‘dst_node_id’, and ‘message_type’ from this message and sets ‘reply_to_message_id’ to the ID of this message.

Parameters:

• content (RecordDict) – The content for the reply message.

• ttl (Optional[float] (default: None)) –

  Time-to-live for this message in seconds. If unset, it will be set based on the remaining time for the received message before it expires. This follows the equation:

  ttl = msg.meta.ttl - (reply.meta.created_at - msg.meta.created_at)

Returns:

A new Message instance representing the reply.

Return type:

Message

property error: Error

Error captured by this message.

has_content() → bool

Return True if message has content, else False.

has_error() → bool

Return True if message has an error, else False.

property metadata: Metadata

A dataclass including information about the message to be executed.