The software utility cron is a time-based scheduler in Unix-like computer operating systems. A user may use cron to schedule jobs (commands or scripts) to run periodically at fixed times, dates, or intervals. A cron statement is composed of 5 fields separated by white space. The *
character translates to "every", ie: "every minute" or "every day of the week".
cron-builder will manage the state of a cron expression, allowing a user to manipulate it through a simple API. It is decoupled from the DOM and doesn't have an opinion about where it's being called from. cron-builder considers this article its source of truth.
cron-builder is available on npm and bower:
npm install cron-builder --save
or
bower install cron-builder --save
After installing, just require the package as you normally would:
var cb = require('/path/to/cron-builder.js');
To instantiate the cron builder:
// (default expression is set to "* * * * *")
var cronExp = new cb();
// optionally, pass in a cron expression to override the default:
var myCronExp = new cb('5 12 * * 1-5')
To return the cron expression at any given time:
cronExp.build();
// '* * * * *'
API includes basic getters and setters:
cronExp.get('minute');
// '*'
cronExp.set('minute', '5,35');
// '5,35'
cronExp.get('minute');
// '5,35'
cronExp.build();
// '5,35 * * * *'
Or if you'd prefer to add or remove values one at a time, use addValue
and removeValue
. These methods build or take away from what is currently set:
cronExp.addValue('hour', '2');
cronExp.addValue('monthOfTheYear', '4');
cronExp.addValue('monthOfTheYear', '10');
cronExp.build();
// '5,35 2 * 4,10 *'
cronExp.removeValue('minute', '5');
cronExp.build();
// '35 2 * 4,10 *'
If you prefer to work with the expression object directly, use getAll
and setAll
:
var exp = cronExp.getAll();
// {minute: ['35'], hour: ['2'], dayOfTheMonth: ['*'], monthOfTheYear: ['4','10'], ...}
exp.dayOfTheMonth = ['7','14','21','28'];
cronExp.setAll(exp);
cronExp.build();
// '35 2 7,14,21,28 4,10 *'
- cron-builder does not currently support using
/
syntax to indicate values that are repeated. Instead of using*/15
, use the verbose form0,15,30,45
. - cron-builder requires using numeric representations of days of the week and months of the year. So instead of using
Feb,Mar,Apr
just use2,3,4
.
Easy!
npm install
npm test
Pull requests and issues appreciated!
- more validation for things like adding values that are already included in a range, better range validations...
- sorting of values for a given measure of time
The MIT License (MIT)