EvaluateExpressionProps

class aws_cdk.aws_stepfunctions_tasks.EvaluateExpressionProps(*, comment=None, heartbeat=None, input_path=None, integration_pattern=None, output_path=None, result_path=None, result_selector=None, timeout=None, expression, runtime=None)

Bases: TaskStateBaseProps

Properties for EvaluateExpression.

Parameters:

  • comment (Optional[str]) – An optional description for this state. Default: - No comment

  • heartbeat (Optional[Duration]) – Timeout for the heartbeat. Default: - None

  • input_path (Optional[str]) – JSONPath expression to select part of the state to be the input to this state. May also be the special value JsonPath.DISCARD, which will cause the effective input to be the empty object {}. Default: - The entire task input (JSON path ‘$’)

  • integration_pattern (Optional[IntegrationPattern]) – AWS Step Functions integrates with services directly in the Amazon States Language. You can control these AWS services using service integration patterns Default: - IntegrationPattern.REQUEST_RESPONSE for most tasks. IntegrationPattern.RUN_JOB for the following exceptions: BatchSubmitJob, EmrAddStep, EmrCreateCluster, EmrTerminationCluster, and EmrContainersStartJobRun.

  • output_path (Optional[str]) – JSONPath expression to select select a portion of the state output to pass to the next state. May also be the special value JsonPath.DISCARD, which will cause the effective output to be the empty object {}. Default: - The entire JSON node determined by the state input, the task result, and resultPath is passed to the next state (JSON path ‘$’)

  • result_path (Optional[str]) – JSONPath expression to indicate where to inject the state’s output. May also be the special value JsonPath.DISCARD, which will cause the state’s input to become its output. Default: - Replaces the entire input with the result (JSON path ‘$’)

  • result_selector (Optional[Mapping[str, Any]]) – The JSON that will replace the state’s raw result and become the effective result before ResultPath is applied. You can use ResultSelector to create a payload with values that are static or selected from the state’s raw result. Default: - None

  • timeout (Optional[Duration]) – Timeout for the state machine. Default: - None

  • expression (str) – The expression to evaluate. The expression may contain state paths. Example value: '$.a + $.b'

  • runtime (Optional[Runtime]) – The runtime language to use to evaluate the expression. Default: lambda.Runtime.NODEJS_14_X

ExampleMetadata:

infused

Example:

convert_to_seconds = tasks.EvaluateExpression(self, "Convert to seconds",
    expression="$.waitMilliseconds / 1000",
    result_path="$.waitSeconds"
)

create_message = tasks.EvaluateExpression(self, "Create message",
    # Note: this is a string inside a string.
    expression="`Now waiting ${$.waitSeconds} seconds...`",
    runtime=lambda_.Runtime.NODEJS_14_X,
    result_path="$.message"
)

publish_message = tasks.SnsPublish(self, "Publish message",
    topic=sns.Topic(self, "cool-topic"),
    message=sfn.TaskInput.from_json_path_at("$.message"),
    result_path="$.sns"
)

wait = sfn.Wait(self, "Wait",
    time=sfn.WaitTime.seconds_path("$.waitSeconds")
)

sfn.StateMachine(self, "StateMachine",
    definition=convert_to_seconds.next(create_message).next(publish_message).next(wait)
)

Attributes

comment

An optional description for this state.

Default:

  • No comment

expression

The expression to evaluate. The expression may contain state paths.

Example value: '$.a + $.b'

heartbeat

Timeout for the heartbeat.

Default:

  • None

input_path

JSONPath expression to select part of the state to be the input to this state.

May also be the special value JsonPath.DISCARD, which will cause the effective input to be the empty object {}.

Default:

  • The entire task input (JSON path ‘$’)

integration_pattern

AWS Step Functions integrates with services directly in the Amazon States Language.

You can control these AWS services using service integration patterns

Default:

  • IntegrationPattern.REQUEST_RESPONSE for most tasks.

IntegrationPattern.RUN_JOB for the following exceptions: BatchSubmitJob, EmrAddStep, EmrCreateCluster, EmrTerminationCluster, and EmrContainersStartJobRun.

See:

https://docs.aws.amazon.com/step-functions/latest/dg/connect-to-resource.html#connect-wait-token

output_path

JSONPath expression to select select a portion of the state output to pass to the next state.

May also be the special value JsonPath.DISCARD, which will cause the effective output to be the empty object {}.

Default:

  • The entire JSON node determined by the state input, the task result,

and resultPath is passed to the next state (JSON path ‘$’)

result_path

JSONPath expression to indicate where to inject the state’s output.

May also be the special value JsonPath.DISCARD, which will cause the state’s input to become its output.

Default:

  • Replaces the entire input with the result (JSON path ‘$’)

result_selector

The JSON that will replace the state’s raw result and become the effective result before ResultPath is applied.

You can use ResultSelector to create a payload with values that are static or selected from the state’s raw result.

Default:

  • None

See:

https://docs.aws.amazon.com/step-functions/latest/dg/input-output-inputpath-params.html#input-output-resultselector

runtime

The runtime language to use to evaluate the expression.

Default:

lambda.Runtime.NODEJS_14_X

timeout

Timeout for the state machine.

Default:

  • None