Message

class Message(metadata: Metadata, content: RecordSet | None = None, error: Error | None = None)

Bases: object

State of your application from the viewpoint of the entity using it.

Parameters:

• metadata (Metadata) – A dataclass including information about the message to be executed.

• content (Optional[RecordSet]) – 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]) – A dataclass that captures information about an error that took place when processing another message.

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: RecordSet

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: RecordSet, 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’ to the ID of this message.

Parameters:

• content (RecordSet) – 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.