Extension: TaskWithFinally State¶

The TaskWithFinally state extends the Task state to provide a “finally” branch, which will be executed both for successful completion of the task, but also whenever a Catcher is triggered due to an error in processing.

The “finally” branch will always be executed prior to the NextState of either the task or the catcher.

No results are returned by the “finally” branch.

class awssl.ext.TaskWithFinally(Name=None, Comment='', InputPath='$', OutputPath='$', NextState=None, EndState=None, ResultPath='$', RetryList=None, CatcherList=None, FinallyState=None, ResourceArn=None, TimeoutSeconds=99999999, HeartbeatSeconds=99999999)¶

The TaskWithFinally state can be used to invoke either an AWS Lambda function or an Activity, which provides a general mechanism for all types of processing. The Task supports retries and catching of specified errors to provide structured error handling, as well as supporting Timeout for processing as one of those error types.

As its name suggests, TaskWithFinally also optionally allows an additional branch to be executed after a successful completion of the task, or if any of the Catcher s are triggered by an error.

Note that the finally branch will not be executed if no Catcher traps the error, so it is recommended that a Catcher is provided that traps States.ALL if the finally branch must always be executed.

Either:

EndState is True and NextState must be None
EndState is False and NextState must be a valid instance of a class derived from StateBase.

Parameters:	Name (str) – [Required] The name of the state within the branch of the state machine Comment (str) – [Optional] A comment describing the intent of this pass state InputPath (str) – [Optional] Filter on the Input information to be passed to the Pass state. Default is “$”, signifying that all the Input information will be provided OutputPath (str) – [Optional] Filter on the Output information to be returned from the Pass state. Default is “$”, signifying that all the result information will be provided EndState (bool) – [Optional] Flag indicating if this state terminates a branch of the state machine. Defaults to `False` NextState (instance of class derived from `StateBase`) – [Optional] Next state to be invoked within this branch. Must not be `None` unless `EndState` is `True` ResultPath (str) – [Optional] JSONPath indicating where results should be added to the Input. Defaults to “$”, indicating results replace the Input entirely. RetryList – [Optional] `list` of `Retrier` instances corresponding to error states that cause the entire set of branches to be retried CatcherList – [Optional] `list` of `Catcher` instances corresponding to error states that can be caught and handled by further states being executed in the `StateMachine`. FinallyState – [Optional] First state of the finally branch to be invoked ResourceArn – [Required] The Arn for the `Lambda` function or `Activity` that the `Task` should invoke
Type:	RetryList: list of `Retrier`
Type:	CatcherList: list of `Catcher`
Type:	FinallyState: Derived from `StateBase`
Type:	ResourceArn: str
Param:	TimeoutSeconds: [Optional] The number of seconds in which the `Task` should complete
Type:	TimeoutSeconds: int
Param:	HeartbeatSeconds: [Optional] The number of seconds between heartbeats from an `Activity`, to indicate it is still running
Type:	HeartbeatSeconds: int

clone(NameFormatString='{}')¶

Returns a clone of this instance, with the clone named per the NameFormatString, to avoid state name clashes.

If this instance is not an end state, then the next state will also be cloned, to establish a complete clone of the branch form this instance onwards.

Parameters:	NameFormatString (str) – [Required] The naming template to be applied to generate the name of the new instance.
Returns:	`TaskWithFinally` – A new instance of this instance and any other instances in its branch.

get_heartbeat_seconds()¶

Returns the heartbeat interval for the TaskWithFinally. If more than two heartbeats are missed then the state will fail with a States.Timeout error.

Returns:	int – The heartbeat seconds for the state.

get_resource_arn()¶

Returns the Arn of the Lambda or Activity that will be invoked by this TaskWithFinally.

Returns:	str – The Arn of the resource to be invoked.

get_timeout_seconds()¶

Returns the timeout seconds for the TaskWithFinally, afterwhich a States.Timeout error is raised.

Returns:	int – The timeout seconds for the state.

set_heartbeat_seconds(HeartbeatSeconds=99999999)¶

Sets the heartbeats seconds for the TaskWithFinally. If more than two heartbeats are missed then the state will fail with a States.Timeout error.

If specified, must not be less than zero seconds. Default value is 99999999.

Param:	HeartbeatSeconds: [Optional] The number of seconds between heartbeats from an `Activity`, to indicate it is still running
Type:	HeartbeatSeconds: int

set_resource_arn(ResourceArn=None)¶

Sets the Arn of the Lambda of Activity to be invoked by this TaskWithFinally. Cannot be None and must be a valid Arn formatted string.

Parameters:	ResourceArn – [Required] The Arn for the `Lambda` function or `Activity` that the `TaskWithFinally` should invoke
Type:	ResourceArn: str

set_timeout_seconds(TimeoutSeconds=99999999)¶

Sets the timeout seconds for the TaskWithFinally, afterwhich a States.Timeout error is raised.

If specified, must not be less than zero seconds. Default value is 99999999.

Param:	TimeoutSeconds: [Optional] The number of seconds in which the `TaskWithFinally` should complete
Type:	TimeoutSeconds: int