Script Task - PHP

CKteixeira · September 3, 2020, 2:14pm

Hello everyone.
I’m fairly new to Camunda and the REST API seems very interesting. I have tried a few things, like for instance adding a User Task to my BPMN, declare a form “embedded:deployment:formTest.html” and afterwards deploying it alongside the BPMN using REST. This works.
What I’m now trying to achieve is to create a Script Task. I have tried creating a PHP file and declaring on my Script Task the deployed PHP file.

Sadly, this doesn’t seem to work, as I get following error:
An error happened while submitting the task form : Cannot submit task form 7307bde1-edd7-11ea-83d1-ace2d310265a: Can’t find scripting engine for ‘php’: scriptEngine is null.

Is there a way to use PHP as a Script Task engine?

Thank you.

aravindhrs · September 3, 2020, 2:22pm

@CKteixeira, Camunda BPM supports scripting with JSR-223 compatible script engine implementations. as of now the supported scripting are Groovy, JavaScript, JRuby and Jython.

https://docs.camunda.org/manual/latest/user-guide/process-engine/scripting/

https://docs.camunda.org/manual/latest/introduction/third-party-libraries/#process-engine

https://docs.camunda.org/manual/latest/reference/bpmn20/tasks/service-task/#external-tasks

By using external task pattern, you can try like this below:

gist.github.com

https://gist.github.com/tistre/70aea9dce8cf4e32d9761cd4b6271309

asset-ingestion.bpmn

<?xml version="1.0" encoding="UTF-8"?>
<bpmn:definitions xmlns:bpmn="http://www.omg.org/spec/BPMN/20100524/MODEL" xmlns:bpmndi="http://www.omg.org/spec/BPMN/20100524/DI" xmlns:di="http://www.omg.org/spec/DD/20100524/DI" xmlns:dc="http://www.omg.org/spec/DD/20100524/DC" xmlns:camunda="http://camunda.org/schema/1.0/bpmn" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" id="Definitions_0w41w6f" targetNamespace="http://bpmn.io/schema/bpmn" exporter="Camunda Modeler" exporterVersion="1.16.2">
  <bpmn:process id="asset-ingestion" name="Asset Ingestion" isExecutable="true">
    <bpmn:startEvent id="StartEvent_1" name="Asset to be ingested">
      <bpmn:outgoing>SequenceFlow_16kf6eb</bpmn:outgoing>
    </bpmn:startEvent>
    <bpmn:sequenceFlow id="SequenceFlow_16kf6eb" sourceRef="StartEvent_1" targetRef="extract-metadata" />
    <bpmn:serviceTask id="extract-metadata" name="Extract metadata" camunda:type="external" camunda:topic="asset-extract-metadata">
      <bpmn:incoming>SequenceFlow_16kf6eb</bpmn:incoming>
      <bpmn:outgoing>SequenceFlow_1ns7sj4</bpmn:outgoing>

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composer.json

{
    "require": {
        "php": ">=7.1.0",
        "ext-pcntl": "*",
        "endpot/camunda-rest-client": "^1.1"
    }
}

worker.php

<?php

namespace Tistre\CamundaDem;

require __DIR__ . '/vendor/autoload.php';

use Camunda\Entity\Request\ExternalTaskRequest;
use Camunda\Service\ExternalTaskService;

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Note: I haven’t tested myself the above example, but it will helpful for you to start with that

CKteixeira · September 4, 2020, 7:09am

@aravindhrs Thank you for your reply.