nocomplexity/camunda-process-examples

Examples with the camunda process templates

Camunda Process Examples

These examples are based of from dotnet template over at: https://github.com/sjefvanleeuwen/camunda-process-template

Setup camunda using docker

docker run -d --name camunda -p 8080:8080 camunda/camunda-bpm-platform:latest

You can model processes using camunda modeler available at: https://camunda.com/download/modeler/

Quiz example

The quiz example exposes a simple BPMN decision process which requests an external REST-API to pull in quiz data and then checks the answer in the json data using an external task written in c#.

The javascript returns the boolean true/false based on a regex search pattern in the data.

Running the sample

dotnet run

 __      __.___  ________________     _____ .______________
/  \    /  |   |/  _____/\_____  \   /  |  ||   \__    ___/
\   \/\/   |   /   \  ___ /   |   \ /   |  ||   | |    |
 \        /|   \    \_\  /    |    /    ^   |   | |    |
  \__/\  / |___|\______  \_______  \____   ||___| |____|
       \/              \/        \/     |__|

quiz camunda processes

Deploying models and start External Task Workers.

PRESS Ctrl-C TO STOP WORKERS.


Adding resource to deployment: quiz.resources.parseAnswer.js
Adding resource to deployment: quiz.resources.quiz.bpmn
Deployment to Camunda BPM succeeded.

Start the process

1. In the camunda cockpit go to processs. Login u/l: demo/demo
   http://localhost:8080/camunda/app/cockpit/default/#/processes
2. Select the 'Quiz' process
3. The following bpmn diagram is shown

4. Go to the tasks screen http://localhost:8080/camunda/app/tasklist/default/#/
5. Click on start process
6. Click on the quiz process
7. As we have no form deployed, camunda allows for setting the variables manually
8. Click on the plus sign
9. Add a property with the name answer of type string

10. Enter either the correct or incorrect answer as specifid in the answer json file shown here:

{
    "quiz": {
        "sport": {
            "q1": {
                "question": "Which one is correct team name in NBA?",
                "options": [
                    "New York Bulls",
                    "Los Angeles Kings",
                    "Golden State Warriros",
                    "Huston Rocket"
                ],
                "answer": "Huston Rocket"
            }
        }
    }
}

11. Execute the task.

12. The engine will execute the external task ParseAnswer (C#)

    class PaserAnswer : IExternalTaskAdapter
    {
        public void Execute(ExternalTask externalTask, ref Dictionary<string, object> resultVariables)
        {
            Console.WriteLine("--- Result variables ---");
            foreach (var item in externalTask.Variables) {
                Console.WriteLine(item.Key.ToString().PadRight(18) + ": " + item.Value.Value.ToString() );
            }
            
            foreach (var item in resultVariables){
                Console.WriteLine(item.Key.ToString());
            }
            Console.WriteLine("------------------------");
            JObject quiz = JObject.Parse(File.ReadAllText(@"..\rest\simple-response.json"));
            var expected =  (string)quiz["quiz"]["sport"]["q1"]["answer"];
            Console.WriteLine("Expected answer:  " + expected);
            var result = string.Equals(expected, externalTask.Variables["answer"].Value);
            Console.WriteLine("correct?          : " + result);
            resultVariables.Add("correct", result);
        }
    }

Execute External Task from topic 'parseanswer': ExternalTask [Id=bd5db4c7-a223-11e8-b75c-0242ac110002, ActivityId=ServiceTask_1]...
--- Result variables ---
answer            : Huston Rocket
------------------------
Expected answer:  Huston Rocket
correct?          : True
...finished External Task bd5db4c7-a223-11e8-b75c-0242ac110002

13. You can now select the task from the tasklist in camunda and claim it in order to finalize the answer.