customization

Workflow as a Service

In this document, we discuss how to integrate your application with bpmn-server as a Service.

We assume that you are already familiar with setting up bpmn-server along with your processes and having them running.

Please note code in this page is for illustration purposes only.

We have two major Applications here, AppServer and WorflowServer

AppServer

This is your standard Business Application providing various tiers/layers including a UI and Business logic

This app requires 'bpmn-client'

In this Application we will designate a class to handle workflow functions, namely 'WorkflowManager'

requires 'bpmn-client';

class WorkflowManager
{
	/**
		from your business logic you decide to issue invoice
	*/
	startInvoice(data)
	{
		var response= await getServer().engine.start('invoice',data,null,userId,{noWait: true});
		...
	}
	/**
		from UI you want to show to the user list of outstanding invoices that need approval
		
	*/
	listDueTasks()
	{
	var items= await getServer().datastore.findInstances({'items.elementId'='Approve','items.status'='wait'});
	
	}
	/**
		as a result of ListDueTasks, your app will provide a UI Form for user input
		
	**/
	approveInvoice(data)
	{
		/**
		this will invoke (complete) that item the user have selected and pass any data
		**/
		var response= await getServer().engine.invoke({'items.id': data.itemId},data,userId,{noWait: true});
	}

}

WorkflowServer

This is your custom installation of bpmn-server

AppDelegate

This is your custom logic to support bpmn-server processes

requires 'bpmn-server';

class MyAppDelegate extends DefaultAppDelegate{
{
	/**
		This is the EventHandler, receives a notification on every event

		issue a notification (email) to appropriate user(s) when a process reaches a User Task
		
	*/
	async executionEvent(context, event) {

		if (context.item) {
			if (event == 'wait' && context.item.element.type == 'bpmn:UserTask')
			{
				 msg=`Notification for '#{context.definition.name}' CaseId: #{context.instance.data.caseId}
						Item '#{context.item.elementId}' now has the status of '#{context.item.status}';
		
				console.log(msg);
			}
		}
	}
		
	}

Putting it Togother

Use Case 1: Staging a Process

In this use case a User invokes some business logic that requires a process start ... When a process reaches a User Task it issues a notification to user(s).

Use Case 2: Viewing Oustatnding Tasks