Camunda ist ein kostenloses [[bpm|BPM]] tool. Es unterstützt [[bpm#cmmn|CMMN]] sowie [[bpm#dmn|DMN]]. Ausserdem unterstützt es externe Tasks mit Hilfe von z.B [[soap|SOAP]] oder integrierter [[https://docs.camunda.org/manual/7.5/reference/rest/|REST API]]. Siehe [[REST]] 

Integration mit [[openkm|OpenKM]] Api möglich. (CMIS specification)

Mit Hilfe des [[coding:java|Java]] [[spring-framework|Spring Framework]] ist es einfach, eigenständige Programme für Geschäftspraktiken- und abläufe zu entwickeln.

Um ein Berechtigungskonzept zu implementieren muss das [[https://docs.camunda.org/manual/7.5/user-guide/process-engine/authorization-service/|Authorisation service]] aktiviert werden! Besser ist eine [[https://docs.camunda.org/manual/7.8/installation/full/tomcat/configuration/#ldap|direkte Anbindung an LDAP]]. Siehe auch [[https://forum.camunda.io/t/how-to-setup-ldap-in-camunda-platform-run/26553]]

<box red>[[https://stackoverflow.com/questions/73399333/camunda-ui-tasklist-slider-overlaps-tasks-in-new-chrome-edge-versions|Chrome Bug Column Size]]</box>

Increase max-file-size - **NOT with Camunda Run**? - Siehe [[https://forum.camunda.io/t/how-to-increase-the-max-file-upload-size-in-generated-forms/38264|Frage im Forum]].

[[https://docs.camunda.org/manual/7.17/user-guide/task-forms/#embedded-task-forms|Usertask embedded form Docs]] - reference using <code>embedded:deployment:form.html</code>

[[https://github.com/camunda/camunda-external-task-client-js/blob/master/README.md|external-task-client-js dok]]

[[https://docs.camunda.org/get-started/spring-boot/|Spring Boot example project]]

[[https://downloads.camunda.cloud/release/camunda-bpm/|Download archive]]

[[https://github.com/zarat/camunda-cockpit-plugins|Minimal history Plugin]]

=====Authorization=====

  * Process definition - Wer darf welchen Prozess starten
  * Filter - Wer darf Filter einstellen
  * Process definition - darf im cockpit und in der tasklist die deployten prozesse und diagramme sehen
  * ProcessInstance CREATE - darf Prozesse starten (damit Subprozesse nicht startbar sind gibt es den Punkt tasklist -> startable in modeller)

=====MySQL Setup=====

[[https://groups.google.com/g/camunda-bpm-users/c/O8dpppcvwt8/m/MXFGeGW8wxoJ|Connect Camunda to MySQL Database instead of H2]]

[[https://forum.camunda.io/t/mysql-configuration-for-springboot-app/38547|Spring Boot right MySQL Driver Installation und connection]]

=====CMMN=====

Um im Camunda modeler das CMMN Modul zu aktivieren startet man das Programm mit dem Parameter 

<code>
--no-disable-cmmn
</code>

=====DMN=====

DMN (Decision making notation) ist eine Auszeichnungssprache für automatisierte Entscheidungen.

[[https://docs.camunda.org/manual/7.17/reference/rest/decision-definition/post-evaluate/|Evaluate a decision via REST api]]

=====Installation=====

====Docker====

Camunda Run 7

<code>
docker pull camunda/camunda-bpm-platform:latest
docker run -d --name camunda -p 8080:8080 camunda/camunda-bpm-platform:latest
docker container start camunda
docker container stop camunda
</code>

Camunda Platform 8

<code>
git clone https://github.com/camunda/docker-camunda-bpm-platform
cd docker-camunda-bpm-platform
docker compose up -d
</code>
=====REST API=====

====Authentication====

In file <code>$CAMUNDA_HOME/server/apache-tomcat/webapps/engine-rest/WEB-INF/web.xml</code> uncomment the lines for basic auth.

====deploy a process====

<code>
POST localhost:8080/engine-rest/deployment/create
Content-Type: multipart/formdata
file: upload
</code>

====Evaluate a process/decision====

<code>
</code>

====start a process====

<code>
POST localhost:8080/engine-rest/process-definition/key/[process-name]/start
Content-Type: application/json
Raw: { /* some initial parameters */ }
</code>

====Assign a running task to a user====

<code>
POST localhost:8080/engine-rest/task/[task-id]/assignee
Content-Type: application/json
data: {"userId": "[user-id]"}
</code>

====Get variables from a running task====

<code>
GET localhost:8080/engine-rest/task/[task-id]/variables
</code>

====delete a started task====

<code>
DELETE localhost:8080/engine-rest/process-instance/[process-instance-id]
</code>

====delete a deployed process====

<code>
DELETE localhost:8080/engine-rest/process-definition/key/[process-name]
</code>

=====Scripting=====

====Python====

<code>
pip install camunda-external-task-client-python3
</code>

<code>
import logging

from camunda.external_task.external_task_worker import ExternalTaskWorker
from examples.task_handler_example import handle_task

logger = logging.getLogger(__name__)

default_config = {
    "maxTasks": 1,
    "lockDuration": 10000,
    "asyncResponseTimeout": 0,
    "isDebug": False,
}


def main():
    #configure_logging()
    while 1:
        try: 
            ExternalTaskWorker(worker_id=1, config=default_config).fetch_and_execute(topic_names=["SendLetter"], action=handle_task)
        except:
            print("No tasks found")

def configure_logging():
    logging.basicConfig(level=logging.INFO, format="%(asctime)s [%(levelname)s] %(message)s", handlers=[logging.StreamHandler()])


if __name__ == '__main__':
    main()
</code>

Pure REST

<code>
import requests
import json
import time

url = 'http://localhost:8080/engine-rest/execution'
task = {}
 
try:
    res = requests.post(url, json=task)
    #print(res.status_code)
    body = res.text        
            
except: 
    print('The engine seems to be down.')


while body == '[]':
    res = requests.post(url, json=task)
    time.sleep(5)    
    if body != '[]':
        break

response = json.loads(body)
        
print(response[0]['id'])
</code>
====NodeJS====

Siehe [[https://github.com/camunda/camunda-external-task-client-js|Camunda External Task NodeJS - Github]]

<code>
npm install -s camunda-external-task-client-js
npm install -s mysql
</code>

<code>
const { Client, logger } = require("camunda-external-task-client-js");
const { Variables } = require("camunda-external-task-client-js");

const config = { baseUrl: "http://localhost:8080/engine-rest" };
const client = new Client(config);
 
// using mysql database
var mysql = require('mysql'); 

var con = mysql.createConnection({
  host: "localhost",
  user: "root",
  database: "test",
  password: ""
});

con.connect(function(err) {
  console.log("Connected!");
  con.query("SELECT * FROM books;", function (err, result) {
    for(var i = 0; i < result.length; i++)
		console.log("Result: " + result[i]['title']);
  });
}); 

client.subscribe("Rechnung", async function({ task, taskService }) {

  console.log("*** Processing task " + task.id);
  
  var uploadedFile = task.variables.get("rechnung");
    
  const http = require('http');
  const fs = require('fs');

  const file = fs.createWriteStream("C:/Users/mzarat/Desktop/" + task.id + "_test.pdf");
  
  const request = http.get("http://localhost:8080/engine-rest" + uploadedFile.remotePath, function(response) {
	
	response.pipe(file);

	// after download completed close filestream
	file.on("finish", () => {
       file.close();
       console.log("*** The file was saved at C:/Users/mzarat/Desktop/" + task.id + "_test.pdf");
	});
  });
  
  const processVariables = new Variables();
  
  //processVariables.set("testIndex", "1");

  // complete the task
  await taskService.complete(task, processVariables);
  
  //console.log("*** Task " + task.id + " completed.");
  
});
</code>

=====Embedded task form=====

Wird im Modeler als zusätzliche Datei geaddet und referenziert mit

<code>embedded:deployment:file.html</code>

<box red>Die Variablen Typen (String, Double,...) müssen Groß geschrieben sein!!!!!</box>
<code>
<form role="form" name="form">

    <div class="form-group">
  
        <label for="customerId-field">Grund</label>
        <input required cam-variable-name="grund" cam-variable-type="String" class="form-control" />
		   
    </div>
	
    <div class="form-group">
	
        <label for="amount-field">Betrag</label>
        <input cam-variable-name="betrag" cam-variable-type="Double" class="form-control" />
		   
    </div>
    
    <div class="form-group">
	
        <label for="amount-field">Betrag</label>
        <select cam-variable-name="type" cam-variable-type="String">
            <option value="Wissen">Wissen</option>
            <option value="Technik">Technik</option>
            <option value="Medikament">Medikament</option>
        </select>
		   
    </div>
    
    <div class="form-group">
    
        <input type="checkbox" cam-variable-name="bool" cam-variable-type="Boolean">
        <label for="vehicle1"> I have a bike</label>
        
    </div>
	
</form>
</code>

Javascript Zugriff auf Prozess Variablen
<code>
<form role="form" name="form">
    <div class="form-group">
        <label for="stefan-field">Stefan</label>
        <input id="stefan-field" required cam-variable-name="stefan" cam-variable-type="Boolean" class="form-control" />
		
		<label for="walter-field">Walter</label>
        <input id="walter-field" required cam-variable-name="walter" cam-variable-type="Boolean" class="form-control" />
		
		<div id="variable-output"></div>
    </div>
	
	<script cam-script type="text/form-script">
        /* Das braucht man nur wenn die variablen noch nicht im formular verwendet werden!
		camForm.on('form-loaded', function() {
            camForm.variableManager.fetchVariable('walter');
            camForm.variableManager.fetchVariable('stefan');
        });
		*/
        camForm.on('variables-fetched', function() {
            $scope.walter = camForm.variableManager.variable('walter').value;
            $scope.stefan = camForm.variableManager.variable('stefan').value;
        });
    </script>

    <p>{{stefan}}</p>
    <p>{{walter}}</p>
	
</form>
</code>
=====Links=====

  * [[https://camunda.com|Homepage]]
  * [[https://docs.camunda.io/|Docs]]
  * [[https://forum.camunda.io/|Forum]]
  * [[https://docs.camunda.org/manual/7.5/reference/rest/|REST API Docs]]
  * [[https://www.postman.com|Postman REST Client]]
  * [[https://www.youtube.com/playlist?list=PLJG25HlmvsOX8TiIGUZcVW-ez053YsOX0|Camunda tutorial playlist]]
  * [[https://www.youtube.com/watch?v=WC3Oh_E-Btk|New way of forms 2021]]
  * [[https://www.youtube.com/watch?v=OME54prHPME|Camunda Connectors,  data, scripting]]
  * [[https://www.youtube.com/watch?v=8SYEc3dHnM4|Messaging tutorial]]
  * [[https://www.youtube.com/watch?v=k-rS2CujP8k|External Task]], [[https://camunda.com/blog/2021/03/external-task-client-spring-bootified/|External task 2]]
  * [[https://www.youtube.com/watch?v=6GHp55PGt_U|Trigger timer and error events tutorial]]
  * [[https://www.youtube.com/watch?v=BwsoozZRAqo|Cockpit development]]
  * [[https://www.youtube.com/watch?v=sgcSm7YneTs|Build Spring Boot Application]]
  * [[https://www.youtube.com/playlist?list=PLJG25HlmvsOVssaiPmavxv3htN_dXS3BW|Spring Boot Application 2]]
  * [[https://www.youtube.com/watch?v=T8dWMFSMJNE|Decision making]]
  * [[https://github.com/camunda/camunda-docs-manual/blob/master/content/user-guide/process-engine/scripting.md#use-script-tasks|Scripting]]
  * [[https://medium.com/@stephenrussett/deploying-embedded-forms-with-camunda-rest-api-84cf8010f8c1|Embedded form deployment]]
  * [[https://www.youtube.com/watch?v=BwsoozZRAqo|Building a cockpit plugin]]