Event

Modules concerning the event handling system used throughout the Gen AI applications.

EventEmitter(handlers, event_level=EventLevel.INFO)

Handles events emitting using event handlers with various levels and types.

The EventEmitter class is responsible for handling and emitting events using a list of event handlers. Events are processed based on their severity level and type, with the option to disable specific handlers.

Attributes:

Name	Type	Description
handlers	list[BaseEventHandler]	A list of event handlers to process emitted events.
severity	int	The minimum severity level of events to be processed.

Raises:

Type	Description
ValueError	If the event handlers list is empty.
ValueError	If an invalid event level is provided.

Initializes a new instance of the EventEmitter class.

Parameters:

Name	Type	Description	Default
handlers	list[BaseEventHandler]	A list of event handlers to process emitted events.	required
event_level	EventLevel	The minimum severity level of events to be processed. Defaults to EventLevel.INFO.	INFO

close() async

Closes all handlers in the handler list.

This method iterates through the list of handlers and calls the close method on each handler.

Returns:

Type	Description
None	None

emit(value, event_level=EventLevel.DEBUG, event_type=EventType.STATUS, disabled_handlers=None) async

Emits an event using the event handlers with the specified severity and type.

This method emits an event by creating an Event object with the provided message, severity level, and event type. It then passes the event to the available handlers, unless they are listed in the disabled handlers. The event will only be processed if its severity is greater than or equal to the configured severity level of the EventEmitter.

Parameters:

Name	Type	Description	Default
value	str	The event message to be emitted.	required
event_level	EventLevel	The severity level of the event. Defaults to EventLevel.DEBUG.	DEBUG
event_type	EventType	The type of event (e.g., status, response). Defaults to EventType.STATUS.	STATUS
disabled_handlers	list[str]	The list of handler names to be disabled. Defaults to None.	None

Returns:

Type	Description
None	None

Raises:

Type	Description
ValueError	If the provided event_level is not a valid EventLevel.
ValueError	If the provided event_type is not a valid EventType.

Messenger(message, is_template=True)

Bases: Component

Emits a custom event message with possible access to the state variables.

This component acts as an intermediary step, designed to be placed between other pipeline steps. It allows for event messaging operations to be performed outside individual components but still within the context of the pipeline execution.

Attributes:

Name	Type	Description
message	str	The message to be sent, may contain placeholders enclosed in curly braces {}.
is_template	bool	Whether the message is a template that can be injected with state variables. Defaults to True.
variable_keys	list[str]	The keys of the message that can be injected with state variables. Only used if is_template is set to True.

Plain string message example:

event_emitter = EventEmitter(handlers=[ConsoleEventHandler()])
kwargs = {"event_emitter": event_emitter}

messenger = Messenger("Executing component.", is_template=False)
await messenger.run(**kwargs)

Template message example:

event_emitter = EventEmitter(handlers=[ConsoleEventHandler()])
state_variables = {"query": "Hi!", "top_k": 10}
kwargs = {"event_emitter": event_emitter, "state_variables": state_variables}

messenger = Messenger("Executing component for query {query} and top k {top_k}.")
await messenger.run(**kwargs)

Initializes a new instance of the Messenger class.

Parameters:

Name	Type	Description	Default
message	str	The message to be sent, may contain placeholders enclosed in curly braces {}.	required
is_template	bool	Whether the message is a template that can be injected with state variables. Defaults to True.	True

Raises:

Type	Description
ValueError	If the keys of the message does not match the provided keys.

send_message(event_emitter, state_variables=None, emit_kwargs=None) async

Emits the message to the event emitter.

This method validates the variables, formats the message if required, and then emits the message using the event emitter.

Parameters:

Name	Type	Description	Default
event_emitter	EventEmitter	The event emitter instance to emit the message.	required
state_variables	dict[str, Any] | None	The state variables to be injected into the message placeholders. Can only be provided if is_template is set to True. Defaults to None.	None
emit_kwargs	dict[str, Any] | None	The keyword arguments to be passed to the event emitter's emit method. Defaults to None.	None