Timers

All Timers are persisted, therefore, if the Node.js session is restared timers will pickup where they left

Timer Types

DateTime (not supported)

  <timerEventDefinition>
        <timeDate>2011-03-11T12:13:14Z</timeDate>
    </timerEventDefinition>

Duration

Example (interval lasting 10 days):

    <timerEventDefinition>
        <timeDuration>P10D</timeDuration>
    </timerEventDefinition>

Time Cycle

Example (3 repeating intervals, each lasting 10 hours):

    <timerEventDefinition>
        <timeCycle>R3/PT10H</timeCycle>
    </timerEventDefinition>

Time Cycle accepts both ISO 8601 format and Cron format

Example for cron format:

    <timerEventDefinition>
        <bpmn:timeCycle xsi:type="bpmn:tFormalExpression">5 * * * *</bpmn:timeCycle>
    </timerEventDefinition>

Development/Test Environment Timer modification

bpmn-server allow you to modify the timer behaviour during development without changing bpmn definition

By changing the configuration.ts to force timers to specific time

let definitionsPath = __dirname + '/processes/';
var configuration = new Configuration(
    {
        definitionsPath: definitionsPath,
        timers: {
            forceTimersDelay: 1000,
            precision: 3000,
        },

Event Types

Event Type	TimeDate	Duration	TimeCycle	TimeCycle Repeat
Start	NA	NA	Yes	Default
Intermediate	NA	Yes	Yes	NA
Boundary Event	NA	Yes	Yes	Yes

• Start Event support 'Time Cycle' only since duration and timeDate make no sense.

• Intermediate Events are implemented as a normal event, will start the timer at start of the node and once the timer is completed the node will end.

• Start Event Timers will start a new execution, therefore, they are scheduled by a cron job managed by bpmn-server.

Implementation:

On Server start:

1. All start event are re-evaluated and reschedules
2. other events that are in wait state are re-evaluated and reschedules