从 Choice 状态传递输入的问题

Question

我正在 Step Function 上做一些实验，所以我设计了这个工作流程。 here is the workflow snapshot

代码：

 {
   "Comment": "SF demo",
   "StartAt": "Map",
   "States": {
   "Map": {
    "Type": "Map",
    "InputPath": "$.Records",
    "ItemsPath": "$.payload",
    "MaxConcurrency": 2,
    "Parameters":{
     "input1.$":"$.choice1",
     "input2.$":"$.choice2"
    },
  "Next": "Final State",
  "Iterator": {
    "StartAt": "ChoiceState",
    "States": {
      "ChoiceState": {
        "Type": "Choice",
        "Choices":[
          {
            "Variable":"$.input1",
            "StringEquals":"input1",
            "Next":"CWT"
          },
          {
            "Variable":"$.input2",
            "StringEquals":"input2",
            "Next":"Lenel"
          }
        ]
      },
      "CWT":{
        "Type":"Task",
        "InputPath":"$.payload",
        "Resource":"***********************",
        "End": true
      },
      "Lenel":{
        "Type":"Task",
        "Resource":"****************",
        "End": true
      }
    }
  }
},
"Final State": {
  "Type": "Pass",
  "End": true
}
}
}

我在处理输入时遇到问题

我将有这种类型的输入：

{
   "Records": {
   "choice1": "input1",
   "choice2": "input2",
   "payload": [
       {
          "Key": "tempfile1.csv"
       }
    ]
 }
 }

我的期望：选择状态将读取数据 "choice1" 和 "choice2" 并将转换到下一个状态，其中将处理 "payload" 数据数组。

但是 "Payload" 数据没有传递到下一个状态，我遇到了这个问题

TaskStateEntered CWT -   238 Mar 18, 2020 12:15:57.070 PM
{
  "name": "CWT",
  "input": {
  "input2": "input2",
   "input1": "input1"
  }

}

 ExecutionFailed        -   238 Mar 18, 2020 12:15:57.070 PM
 {
 "error": "States.Runtime",
 "cause": "An error occurred while executing the state 'CWT' (entered at the event id #7). 
  Invalid path 
 '$.payload' : No results for path: $['payload']"
  }

Answer 1

由于您在地图状态中指定了 "Parameters"，因此输入会按照 docs:

中指定的方式被覆盖

"The input to each iteration, by default, is a single element of the array field identified by the ItemsPath value, This may be overridden using the Parameters field."

因此，要解决此问题，您需要使用映射状态的 context object 重新映射参数中的 "payload" 键。这是您的状态机示例，其中 "payload" 键已重新映射：

{
  "Comment": "SF demo",
  "StartAt": "Map",
  "States": {
    "Map": {
      "Type": "Map",
      "InputPath": "$.Records",
      "ItemsPath": "$.payload",
      "MaxConcurrency": 2,
      "Parameters": {
        "input1.$": "$.choice1",
        "input2.$": "$.choice2",
        "payload.$": "$$.Map.Item.Value"
      },
      "Next": "Final State",
      "Iterator": {
        "StartAt": "ChoiceState",
        "States": {
          "ChoiceState": {
            "Type": "Choice",
            "Choices": [
              {
                "Variable": "$.input1",
                "StringEquals": "input1",
                "Next": "CWT"
              },
              {
                "Variable": "$.input2",
                "StringEquals": "input2",
                "Next": "Lenel"
              }
            ]
          },
          "CWT": {
            "Type": "Pass",
            "InputPath": "$.payload",
            "End": true
          },
          "Lenel": {
            "Type": "Pass",
            "InputPath": "$.payload",
            "End": true
          }
        }
      }
    },
    "Final State": {
      "Type": "Pass",
      "End": true
    }
  }
}

从 Choice 状态传递输入的问题

Problem in passing inputs from Choice state

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