Scripting

• Introduction
• Model Expressions/Scripts
  • Model Expressions
  • Model Listeners
• Execution Listeners
  • Task Listeners
• Application Listener
  • Scripts Scope and variables
• Item Scope
• Execution Scope
• Application Listener

Introduction

Scripting is using NodeJs JavaScript engine.
scripts have full access to the running working full, as well as your application logic in:

• AppDelegate class; as a general entry point
• AppServices class; that responds to Service Tasks
• AppUtils class; general purpose class to make your scripts more powerfull

Scripting is used to add logic to your workflow and is achieved by:

Model Expressions/Scripts

Model Expressions

conditional flow examples:

timers examples:

For duration timers

    $appServices.dateAdd(item.dateStarted,10,'days')

Input/Output

Assignment properties

User Task Assignment properties can be JavaScript expression, in this case they must start with ‘$’

For example:

assignee $(this.data.requester)

Model Listeners

Inside your model, you can attach Listeners to various nodes as JavaScript Listeners

These are similar to expressions above but can invoke async functions and can include more complete Javascript

No syntax required for these scripts

Examples

    let userManager=await appServices.retrieveManagerForUser(item.userName);

    data.manager=userManager;

    if (data.var1>5) {
        data.message='any text here';
    }

Execution Listeners

These are for all node types and processes

Task Listeners

    // do some checking here
    return {error:'Not a valid Input'};

Application Listener

You can place a listener in your application delegate or your execution scripts class to listen to all events
Example:

    const api = new BPMNAPI(new BPMNServer(configuration,new Logger({ toConsole: false}),{cron:false}));

    let options= {option1:1234}; //,option2:SystemUser};

    api.server.listener.on('all', async function ({ context, event, }) {
        if (event=='process.restored')
            {
            context.options=options;
            context.options['restored']=true;
            }
        if (event.startsWith('process.'))
            console.log('---Event: -->' + event , context.options);
        else 
            console.log('---Event: -->'+event, 'item:',context.item.elementId,context.options );
    });

Scripts Scope and variables

Item Scope

Items Expressions and Listeners have the following variables

• Common Item properties:

  id;                 
  options;
  context;    //execution options
  elementId;  // Model Node Id

• Item methods

  log(msg)        // issues a log message into the logger
  info(msg)       // issues an information message

• Execution (context) properties

  instance: InstanceObject;
  tokens = new Map();
  definition: IDefinition;
  process : Process;
  item;
  messageMatchingKey;
  userName;
  servicesProvider;
  options;
  operation;

  Execution Scope

  Expressions and Listeners have the following variables

Application Listener

You can place a listener in your application delegate or your execution scripts class to listen to all events
Example:

    const api = new BPMNAPI(new BPMNServer(configuration,new Logger({ toConsole: false}),{cron:false}));

    let options= {option1:1234}; //,option2:SystemUser};

    api.server.listener.on('all', async function ({ context, event, }) {
        if (event=='process.restored')
            {
            context.options=options;
            context.options['restored']=true;
            }
        if (event.startsWith('process.'))
            console.log('---Event: -->' + event , context.options);
        else 
            console.log('---Event: -->'+event, 'item:',context.item.elementId,context.options );
    });