When a watch is triggered, its condition determines whether or not to execute the watch actions. Watcher supports the following condition types:
-
always
: set the watch condition totrue
so the watch actions are always executed. -
never
: set the watch condition tofalse
so the watch actions are never executed. -
compare
: perform simple comparisons against values in the watch payload to determine whether or not to execute the watch actions. -
array_compare
: compare an array of values in the watch payload to a given value to determine whether or not to execute the watch actions. -
script
: use a script to determine wehther or not to execute the watch actions.

If you omit the condition definition from a watch, the condition defaults
to always
.
When a condition is evaluated, it has full access to the watch execution context,
including the watch payload (ctx.payload.*
). The script,
compare and array_compare
conditions can use the payload data to determine whether or not the necessary
conditions are met.