c# - elsa 工作流 - 子工作流 - 如何获取父工作流的 workflowInstanceId

Question

我有一个 elsa 工作流 parent，它正在调用一些 child 工作流。每个子工作流都有一些自定义活动（基于 SendHttpRequest elsa activity）。这些自定义活动需要调用外部 api 并提供 parent 工作流的 workflowInstanceId。

我试图将 parent 的 workflowInstanceId 作为子工作流的 ContextId 传递——不起作用，因为在子工作流自定义 activity 中被覆盖（这很有意义当然）。

我如何从子工作流中运行的一段代码中获取（服务器端）parent 工作流的 workflowInstanceId （假设来自 OnExecuteAsync(ActivityExecutionContext context) 的子工作流自定义 activity）？

Answer 1

尽管 Elsa 2（撰写本文时为 2.6）没有真正的 parent-child 工作流概念（即其他工作流调用的工作流没有对其父级的任何引用），您可以使用RunWorkflow activity 为子工作流提供任意输入。包括它自己的工作流实例 ID。

例如在RunWorkflowactivity上使用如下JS表达式将工作流实例发送给子工作流：

({ parentWorkflowInstanceId: workflowInstanceId })

然后，从您的子工作流中，您的第一个 activity 应该是捕获此值的那个，例如使用 SetVariable activity:

input.parentWorkflowInstanceId

现在您已将父工作流实例 ID 存储在工作流变量中，您可以从子工作流中的任何位置访问它。

这是您可以通过设计器导入的父工作流示例：

{
  "$id": "1",
  "definitionId": "f3da997090fe4752b4f7abf799f372a8",
  "versionId": "8d6c6e2b441a4d22952a7b19ebf9ceca",
  "name": "Parent",
  "version": 2,
  "variables": {
    "$id": "2",
    "data": {}
  },
  "customAttributes": {
    "$id": "3",
    "data": {}
  },
  "isSingleton": false,
  "persistenceBehavior": "WorkflowBurst",
  "deleteCompletedInstances": false,
  "isPublished": true,
  "isLatest": true,
  "activities": [
    {
      "$id": "4",
      "activityId": "2952daee-646e-431f-b02b-006557507755",
      "type": "RunWorkflow",
      "displayName": "Run Workflow",
      "persistWorkflow": false,
      "loadWorkflowContext": false,
      "saveWorkflowContext": false,
      "properties": [
        {
          "$id": "5",
          "name": "WorkflowDefinitionId",
          "syntax": "Liquid",
          "expressions": {
            "$id": "6",
            "Liquid": "{{ \"Child\" | workflow_definition_id: \"name\" }}"
          }
        },
        {
          "$id": "7",
          "name": "Input",
          "syntax": "JavaScript",
          "expressions": {
            "$id": "8",
            "JavaScript": "({ parentWorkflowInstanceId: workflowInstanceId})"
          }
        },
        {
          "$id": "9",
          "name": "PossibleOutcomes",
          "expressions": {
            "$id": "10"
          }
        },
        {
          "$id": "11",
          "name": "Mode",
          "expressions": {
            "$id": "12"
          }
        },
        {
          "$id": "13",
          "name": "TenantId",
          "expressions": {
            "$id": "14"
          }
        },
        {
          "$id": "15",
          "name": "CorrelationId",
          "expressions": {
            "$id": "16"
          }
        },
        {
          "$id": "17",
          "name": "ContextId",
          "expressions": {
            "$id": "18"
          }
        },
        {
          "$id": "19",
          "name": "CustomAttributes",
          "expressions": {
            "$id": "20"
          }
        }
      ],
      "propertyStorageProviders": {}
    },
    {
      "$id": "21",
      "activityId": "2a6d90ee-5e7a-4d68-8629-386abdaf70ad",
      "type": "HttpEndpoint",
      "displayName": "HTTP Endpoint",
      "persistWorkflow": false,
      "loadWorkflowContext": false,
      "saveWorkflowContext": false,
      "properties": [
        {
          "$id": "22",
          "name": "Path",
          "expressions": {
            "$id": "23",
            "Literal": "/parent"
          }
        },
        {
          "$id": "24",
          "name": "Methods",
          "expressions": {
            "$id": "25",
            "Json": "[\"GET\"]"
          }
        },
        {
          "$id": "26",
          "name": "ReadContent",
          "expressions": {
            "$id": "27"
          }
        },
        {
          "$id": "28",
          "name": "TargetType",
          "expressions": {
            "$id": "29"
          }
        },
        {
          "$id": "30",
          "name": "Schema",
          "syntax": "Literal",
          "expressions": {
            "$id": "31",
            "Literal": ""
          }
        },
        {
          "$id": "32",
          "name": "Authorize",
          "expressions": {
            "$id": "33"
          }
        },
        {
          "$id": "34",
          "name": "Policy",
          "expressions": {
            "$id": "35"
          }
        }
      ],
      "propertyStorageProviders": {}
    }
  ],
  "connections": [
    {
      "$id": "36",
      "sourceActivityId": "2a6d90ee-5e7a-4d68-8629-386abdaf70ad",
      "targetActivityId": "2952daee-646e-431f-b02b-006557507755",
      "outcome": "Done"
    }
  ],
  "id": "8d6c6e2b441a4d22952a7b19ebf9ceca"
}

这是您可以导入的 Child：

{
  "$id": "1",
  "definitionId": "81efcdb2f9aa473a84931814f5ee1c65",
  "versionId": "cc21182603564d68876efd9079382c27",
  "name": "Child",
  "version": 1,
  "variables": {
    "$id": "2",
    "data": {}
  },
  "customAttributes": {
    "$id": "3",
    "data": {}
  },
  "isSingleton": false,
  "persistenceBehavior": "WorkflowBurst",
  "deleteCompletedInstances": false,
  "isPublished": true,
  "isLatest": true,
  "activities": [
    {
      "$id": "4",
      "activityId": "83c6931f-f481-47c0-add8-3b1ea7d864a2",
      "type": "SetVariable",
      "displayName": "Set ParentWorkflowInstanceId Variable",
      "persistWorkflow": false,
      "loadWorkflowContext": false,
      "saveWorkflowContext": false,
      "properties": [
        {
          "$id": "5",
          "name": "VariableName",
          "expressions": {
            "$id": "6",
            "Literal": "ParentWorkflowInstanceId"
          }
        },
        {
          "$id": "7",
          "name": "Value",
          "syntax": "JavaScript",
          "expressions": {
            "$id": "8",
            "JavaScript": "input.parentWorkflowInstanceId"
          }
        }
      ],
      "propertyStorageProviders": {}
    },
    {
      "$id": "9",
      "activityId": "80e7eb8f-3fca-42a7-be3d-16827bd6ba38",
      "type": "WriteHttpResponse",
      "displayName": "HTTP Response",
      "persistWorkflow": false,
      "loadWorkflowContext": false,
      "saveWorkflowContext": false,
      "properties": [
        {
          "$id": "10",
          "name": "Content",
          "syntax": "Liquid",
          "expressions": {
            "$id": "11",
            "Liquid": "Parent ID: {{ Variables.ParentWorkflowInstanceId }}"
          }
        },
        {
          "$id": "12",
          "name": "ContentType",
          "expressions": {
            "$id": "13"
          }
        },
        {
          "$id": "14",
          "name": "StatusCode",
          "expressions": {
            "$id": "15"
          }
        },
        {
          "$id": "16",
          "name": "CharSet",
          "expressions": {
            "$id": "17"
          }
        },
        {
          "$id": "18",
          "name": "ResponseHeaders",
          "expressions": {
            "$id": "19"
          }
        }
      ],
      "propertyStorageProviders": {}
    }
  ],
  "connections": [
    {
      "$id": "20",
      "sourceActivityId": "83c6931f-f481-47c0-add8-3b1ea7d864a2",
      "targetActivityId": "80e7eb8f-3fca-42a7-be3d-16827bd6ba38",
      "outcome": "Done"
    }
  ],
  "id": "cc21182603564d68876efd9079382c27"
}

导入后，确保两个工作流都已发布。然后，您可以通过其 HTTP 端点调用父工作流，例如：https://localhost:11000/parent

这将导致类似于此的响应：

Parent ID: 0178617bbeca47088e74330c0905237c

此响应由子工作流（成功接收到父工作流实例 ID）生成

c# - elsa 工作流 - 子工作流 - 如何获取父工作流的 workflowInstanceId

c# - elsa workflow - child workflow - how to get workflowInstanceId of parent workflow

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