Camunda

发布流程

完成流程设计后，需要发布流程
官网教程知乎
create Api

 http://localhost:8080/engine-rest/deployment/create

Parameters Request Body

xml 是 bpmn 文件，发布流程需要传送文件的文件流数据

const dpm = new FormData()
dpm.append('deployment-name', 'payment')
dpm.append('deployment-source', 'Camunda Modeler')
dpm.append('enable-duplicate-filtering', true)
dpm.append(
  'Content-Disposition: form-data;name="payment.bpmn";filename="payment.bpmn";Content-Type: text/xml',
  new Blob([xml])
)

开始流程

请求接口

http://localhost:8080/engine-rest/process-definition/key/${ID}/start

请求头设置 Content-Type = application/json

请求参数

{
  "variables": {
    "amount": {
      "value":555,
      "type":"integer"
    },
    "item": {
      "value": "item-xyz"
    }
  }
}

process-instance

Activity Instance

通过 id 检索给定流程实例的活动实例（树 API

/process-instance/dcb58801-34c1-11ed-8348-00d8617d5d1d/activity-instances

form-variables

form-variables 检索任务的表单项，如果定义了表单，则返回表单项内容

// GET
/task/{id}/form-variables

UserTask

submit-form Api

// API
http://localhost:8080/engine-rest/task/0e9396b2-34bd-11ed-b695-00d8617d5d1d/submit-form

// Parameters:
{
    "variables": {
        "amount": {
            "value": 9568751
        },
        "item": {
            "value": "item"
        },
        "approved": {
            "value": true
        }
    }
}

Service Tasks

Service Tasks 触发有几种方法，以下是使用 External Tasks 触发.

External Tasks 可以选择java或NodeJs编写外部任务，每当走到 Service Task，都会触发外部任务

上图是一个触发 Service Task 的流程实例，当前节点是在 Service Task 处

node task Worker

Implement an external task worker

const { Client, logger } = require('camunda-external-task-client-js')
const open = require('open')
var fs = require('fs') // 引入fs模块

// configuration for the Client:
//  - 'baseUrl': url to the Process Engine
//  - 'logger': utility to automatically log important events
//  - 'asyncResponseTimeout': long polling timeout (then a new request will be issued)
const config = {
  baseUrl: 'http://localhost:8080/engine-rest',
  use: logger,
  asyncResponseTimeout: 10000,
}

// create a Client instance with custom configuration
const client = new Client(config)

// susbscribe to the topic: 'charge0914'
client.subscribe('charge0914', async function ({ task, taskService }) {
  // Put your business logic here

  // Get a process variable
  const amount = task.variables.get('amount')
  const item = task.variables.get('item')

  console.log(
    `Charging credit card with an amount of ${amount}€ for the item '${item}'...`
  )

  fs.writeFile(
    './taskService.txt',
    JSON.stringify(task),
    { flag: 'a' },
    function (err) {
      if (err) {
        throw err
      }
      // 写入成功后读取测试
      // fs.readFile('./taskService.txt', 'utf-8', function(err, data) {
      //     if (err) {
      //         throw err;
      //     }
      //     console.log(data);
      // });
    }
  )
  open('https://docs.camunda.org/get-started/quick-start/success')

  // Complete the task
  await taskService.complete(task)
})

通过 complete 可以完成该流程任务

complete Api
示例所需要的参数对应上图

// API 接口
http://localhost:8080/engine-rest/external-task/{externalTaskid}/complete

// Request Body
{
  "workerId": ${workerId}
}

Worker Id 为空

在使用时，我发现当 externalTask没有开启脚本的时候WorkerId有为空的情况， node ./xx.js运行脚本就没有问题了。

reference

Camunda Rest Api