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

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Cron expressions

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.
Important: Only Spring cron expressions are permissible for configuration. Refer to the official documentation for detailed information on configuring Spring Cron expressions.
Subexpressions:
  1. Seconds
  2. Minutes
  3. Hours
  4. Day-of-Month
  5. Month
  6. Day-of-Week
  7. 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

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Cron Expressions are used in the following example:

  • Process definition - Expiry time - a user can set up a expiryTime function on a process, for example, a delay of 30s will be set up like:

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ISO 8601

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 intervals, recurring time intervals, etc. More details: ISO 8601 date format ISO 8601 duration format

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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 acceptedValue 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