How to add conditions for job execution with date calculation

Scope

By use of Scripting conditions can be added that are checked before a job will be executed.
Such conditions can include dynamic date calculation to check if the current date is confirmed for execution of a job.
Scripted conditions are considered more dynamic and flexible than configurable conditions.

Scripted Conditions

Scripted conditions can be added by use of Pre- and Postprocessing Scripts.
Each job can be assigned a number of Pre- and Postprocessing scripts that are executed in the configured sequence.
The scripts can include
- Java classes
- JavaScript code
Scripted conditions are a powerful means for flexibility:
- JavaScript code can be added directly to Jobs and Monitors and is interpreted at run-time. No build cycle is required.
- Java classes can be added that make use of of the ecosystem of available Java libraries.
The JobScheduler exposes its objects, methods and properties by use of the API Interface.
- Find details and examples with the Reference Documentation.
Scripted conditions are applied by implementing a spooler_process_before() method for jobs in a ob chain that will
- return the value true if the job should start,
- return the value false if the job should not start,
- move Orders to the next state in a job chain if the current job should be skipped.

Date Calculation

Date calculation can be performed by use of JavaScript and Java:
- JavaScript provides built-in date calculation capabilities.
  - There is always room for improvement. A good example is the date.js library that is
    - released under the MIT License and
    - available for download at GoogleCode with a
    - comprehensible API Documentation.
- Java extends the JavaScript capabilities if used with specific libraries for date calculation.
Date calculation is an intrinsic topic when considering time zones, daylight saving time, leap years etc. which is why we estimate scripting to be superior to using GUIs when it comes to more complex conditions.

Examples

The following examples make use of the date.js library that is included with the monitor scripts as in the following screenshot:

Run a job on the first week of each month

The standard job configuration as offered by JOE allows to specify either specific days, e.g. first Monday of a month, or specific dates, e.g. 1st to 7th.

In order to use both restrictions a scripted condition like this would apply:

function spooler_process_before() {
    var isJobRunEnabled = true;

    if ( isJobRunEnabled ) {
        // check execution for the first week of a month
        if ( Date.today().getDay() <= 7 ) {
            var weekdayOffset = Date.parse( (1900+Date.today().getYear()) + '-' + (1+Date.today().getMonth()) + '-01' ).getDay();
            isJobRunEabled = ( ( 7 - weekdayOffset - Date.today().getDay() ) >= 0 );
            spooler_log.info( "result = (7 - weekdayOffset [" + weekdayOffset + "] - Date.today().getDay() [" + Date.today().getDay() + "]) >= 0 : " + isJobRunEnabled );
        }
        spooler_log.info( ".. job date check for run on first week of month: " + isJobRunEnabled );
    }

    if ( !isJobRunEnabled ) {
	    spooler_task.order.state = "job_next";
	}

	return isJobRunEnabled;
}

Run a job on Thursday and Friday after the 5th and before 15th day of a month

The standard job configuration as offered by JOE allows to specify either specific weekdays or a range of days.