Timer expressions

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

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.

info

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.

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

Cron Expressions are used in the following example:

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

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 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