I have a requirement to store the task id of the activity which is currently active in the process.
I was planning use the tw.system,step API to fetch the task id.IS there any way to store the task id(invoke a service to store it in db) without disturbing the current activity.

Let me know if there are other means to fetch the task id if I know the instance id of the process(TWSearch ,task API?).

Thank You.

Sathish,

I believe the simplest solution would be to put a 0 duration timer on the task that goes to the service that will store the task ID via the tw.system.step API you mentioned. You would also be able to look at the Instance Details REST API to derive some task information, but you would still need something to trigger the call to put the task in the database, so you would still need the timer.

The only alternative to the timer I can think of off the top of my head would be to use the Dynamic Event Framework.

Hope this helps!

var tasks = tw.system.findProcessInstanceByID(id).tasks;
for(task in tasks){
    if(task.status == "Received"){
        log.info("TaskId of currently active task is: " + task.id);
}

This will also do the trick, provided you are okay with finding any running task in the processinstance. If you are executing from within the task, you can also use 
tw.system.currentTask.id