删除上一步中的字段

Question

我正在尝试从上一步中删除仅在选择任务中使用的字段。 我有这个 StepFunction

{
  "StartAt": "ConversionStep",
  "States": {
    "ConversionStep": {
      "Type": "Task",
      "TimeoutSeconds": 30,
      "Resource": "arn:aws:lambda:region:account-id:function:conversion-step",
      "Retry": [
        {
          "ErrorEquals": [
            "RetryError",
            "States.Timeout"
          ],
          "IntervalSeconds": 30,
          "MaxAttempts": 3
        }
      ],
      "Catch": [
        {
          "ErrorEquals": [
            "States.TaskFailed"
          ],
          "Next": "Failure"
        }
      ],
      "Next": "ChoiceStep"
    },
    "ChoiceStep": {
      "Type": "Choice",
      "Choices": [
        {
          "Variable": "$.processEvent",
          "BooleanEquals": true,
          "Next": "PublishStep"
        }
      ],
      "Default": "Failure"
    },
    "PublishStep": {
      "Type": "Task",
      "Resource": "arn:aws:states:::events:putEvents",
      "Parameters": {
        "Entries": [
          {
            "Detail.$": "$",
            "EventBusName": "example-event-bus",
            "DetailType": "example-detail-type",
            "Source": "EXAMPLE_SOURCE"
          }
        ]
      },
      "Retry": [
        {
          "ErrorEquals": [
            "RetryError",
            "States.Timeout"
          ],
          "IntervalSeconds": 30,
          "MaxAttempts": 3
        }
      ],
      "Catch": [
        {
          "ErrorEquals": [
            "States.TaskFailed"
          ],
          "Next": "Failure"
        }
      ],
      "Next": "Success"
    },
    "Success": {
      "Type": "Succeed"
    },
    "Failure": {
      "Type": "Fail"
    }
  }
}

在转换步骤中，在事件中添加

processEvent

。 我需要在发布步骤中发送没有此字段的转换步骤结果

"Detail.$": "$",

有没有办法可以在不创建另一个 Lambda 步骤的情况下做到这一点？ 选择步骤没有结果过滤功能。

Answer 1

现在可以通过使用 Transform Operator 最近推出的对 JSONata 的支持来实现这一点。

您需要更新状态才能使用

"QueryLanguage": "JSONata"

（您可以对整个状态机执行此操作，或者如果您不想更改其余部分，则可以仅针对此状态执行此操作，并将“$”（JSONPath 输入引用）替换为像这样的东西：

"{% $states.input ~> | ** | {}, ['processEvent'] | %}"