When working with FLOWX.AI components, there are multiple scenarios in which timer expressions are needed.
There are two timer expressions formats supported:
- Cron Expressions - used to define the expiry date on processes
- ISO 8601 - used to define the duration of a response timeout or for a timer expression
A cron expression is a string made up of six mandatory subexpressions (fields) that each specifies an aspect of the schedule (for example,
* * * * * *). These fields, separated by white space, can contain any of the allowed values with various combinations of the allowed characters for that field.
A field may be an asterisk (
*), which always stands for “first-last”. For the day-of-the-month or day-of-the-week fields, a question mark (
?) may be used instead of an asterisk.
- Year (optional field)
An example of a complete cron-expression is the string
0 0 12 ? * FRI - which means every Friday at 12:00:00 PM.
More details:»Scheduling cron expressions
Cron Expressions are used in the following example:
- Process definition - Expiry time - a user can set up an
expiryTimefunction on a process, for example, a delay of 30s will be set up like:
ISO 8601 is an international standard covering the worldwide exchange and communication of date and time-related data. It can be used to standardize the following: dates, time of delay, time intervales, recurring time intervals, etc.
More details:»ISO 8601
ISO 8601 format is used in the following examples:
- Node config - Response Timeout - can be triggered if, for example, a topic that you define and add in the Data stream topics tab does not respect the pattern
ISO 8601 dates and times:
|Format accepted||Value ranges|
|Year (Y)||YYYY, four-digit, abbreviatted to two-digit|
|Month (M)||MM, 01 to 12|
|Week (W)||WW, 01 to 53|
|Day (D)||D, day of the week, 1 to 7|
|Hour (h)||hh, 00 to 23, 24:00:00 as the end time|
|Minute (m)||mm, 00 to 59|
|Second (s)||ss, 00 to 59|
|Decimal fraction (f)||Fractions of seconds, any degree of accuracy|
- Actions - Timer expression - it can be used if a delay is required on that action