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活动)。这些自定义活动需要调用外部api并提供workflowInstanceId of parent工作流。

我试图将workflowInstanceId of parent作为子工作流的ContextId传递--因为在子工作流自定义活动中被覆盖了(这当然是有意义的)。

如何从运行在子工作流上的代码(例如来自子工作流自定义活动的workflowInstanceId )获得(服务器端) parent工作流？

Answer 1

虽然Elsa 2(在编写本报告时为2.6)没有父-子工作流的真正概念(即其他工作流调用的工作流没有对其父工作流的任何引用)，但您可以使用RunWorkflow活动向子工作流提供任意的输入。包括它自己的工作流实例ID。

例如，在RunWorkflow活动中使用以下JS表达式将工作流实例发送到子工作流：

({ parentWorkflowInstanceId: workflowInstanceId })

然后，从您的子工作流中，您的第一个活动应该是捕获这个值的活动，例如使用一个SetVariable活动：

input.parentWorkflowInstanceId

现在，您已经将父工作流实例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。

下面是一个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"
}

这是你可以进口的孩子：

{
  "$id": "1",
  "definitionId": "81efcdb2f9aa473a84931814f5ee1c65",
  "versionId": "cc21182603564d68876efd9079382c27",
  "name": "Child",
  "version": 1,
  "variables": {
    "$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

这将导致类似这样的反应：

Parent ID: 0178617bbeca47088e74330c0905237c

此响应由子工作流(成功接收父工作流实例ID)生成。