Interval Plugin
The Imixs Plugin org.imixs.workflow.engine.plugins.IntervalPlugin provides an easy way for computing periodical intervals.
The Plugin implements an mechanism to adjust the value of a date item based on a macro or a cron definition.
The interval can be defined in the workflow result by setting a reference item by name and a cron definition. See the following example:
<item name="interval">
<ref>reminder</ref>
<cron>0 15 * * 1-5</cron>
</item>
This example will adjust the date item ‘reminder’ to 3:00pm the next working day (Mo-Fr).
<item name="interval">
<ref>reminder</ref>
<macro>@monthly</macro>
</item>
This example will adjust the value of the date item ‘reminder’ per 1 month. For example: 15.01.2020 => 15.02.2020
Cron Expression
The syntax of a cron expression is made of five fields:
┌───────────── minute (0 - 59)
│ ┌───────────── hour (0 - 23)
│ │ ┌───────────── day of the month (1 - 31)
│ │ │ ┌───────────── month (1 - 12)
│ │ │ │ ┌───────────── day of the week (0 - 6) (Sunday to Saturday);
│ │ │ │ │
│ │ │ │ │
│ │ │ │ │
* * * * *
See the following examples how you can schedule workitems on intervals:
| Cron | Description |
|---|---|
| 0 0 1 1 * | Schedule once a year at midnight of 1 January |
| 0 0 1 * * | Schedule once a month at midnight of the first day of the month |
| 0 0 * * 0 | Schedule once a week at midnight on Sunday morning |
| 0 0 * * * | Schedule once a day at midnight |
| 0 * * * * | Schedule once an hour at the beginning of the hour |
| 0 15 * * 7 | Schedule every Sunday on 3:00 pm |
Macro Definitions
The following macros can be used to schedule a workitem based on given date item value:
| Macro | Description |
|---|---|
| @yearly | Run every year on the same day and month |
| @monthly | Run every month on the same day |
| @weekly | Run every week on the same day of week |
| @daily | Run every day on the same hour and the same minute |
| @hourly | Run every hour on the same minute |
