Simple Map

This example demonstrates using the Map state to run a Task over every member of a part of the state machine data.

python

json

"""
Simple workflow using the Map state.
"""
from rhodes.states import Map, StateMachine, Task
from rhodes.structures import ContextPath, JsonPath, Parameters


def build() -> StateMachine:
    validate_task = Task(
        "Validate", Resource="arn:aws:lambda:us-east-1:123456789012:function:ship-val"
    )

    state_iterator = StateMachine()
    state_iterator.start_with(validate_task).end()

    mapper = Map(
        "ValidateAll",
        InputPath=JsonPath("$.detail"),
        ItemsPath=JsonPath("$.shipped"),
        Parameters=Parameters(
            Execution=ContextPath().Execution.Id, Payload=JsonPath("$")
        ),
        MaxConcurrency=0,
        Iterator=state_iterator,
        ResultPath=JsonPath("$.detail.shipped"),
    )

    workflow = StateMachine(Comment="Simple state machine with one map state")
    workflow.start_with(mapper).end()

    return workflow

{
    "Comment": "Simple state machine with one map state",
    "StartAt": "ValidateAll",
    "States": {
        "ValidateAll": {
            "Type": "Map",
            "InputPath": "$.detail",
            "ItemsPath": "$.shipped",
            "MaxConcurrency": 0,
            "Parameters": {
                "Execution.$": "$$.Execution.Id",
                "Payload.$": "$"
            },
            "Iterator": {
                "StartAt": "Validate",
                "States": {
                    "Validate": {
                        "Type": "Task",
                        "Resource": "arn:aws:lambda:us-east-1:123456789012:function:ship-val",
                        "InputPath": "$",
                        "OutputPath": "$",
                        "ResultPath": "$",
                        "End": true
                    }
                }
            },
            "ResultPath": "$.detail.shipped",
            "OutputPath": "$",
            "End": true
            }
    }
}