Once

Name	Mandatory	Description	Default	Type
⬅️ Input		The input of the shard, if any		Any
Output ➡️		The resulting output of the shard		Any
Action	No	The shard or sequence of shards to execute.	none	Shard[Shard]
Every	No	The number of seconds to wait until repeating the action, if 0 the action will happen only once per wire flow execution.	none	FloatVar(Float)

Executes the shard or sequence of shards with the desired frequency in a wire flow execution.

Details

If you run (Once) with :Every set to its default value (i.e., 0), the sequence of shards will be executed only once per wire flow execution. Since this a very common use case (initialize loop counters, etc.) there's an alias for this - (Setup).

Basically, (Setup) is just (Once) with its :Every parameter value permanently set to 0.

Examples

Code

; Once
@wire(test1 {
  "Hello World, every 1.5s during a wire flow execution" = string1
  "Hello World, once during every wire flow execution" = string2

  string1 | Once({
    Log
  } Every: 1.5) ; string logs once every 1.5 secs i.e for a total of 3 times

  string2 | Once({
    Log
  }) ; Every defaults to 0 so this string logs only once
})

; here one wire flow execution is 5 secs (5 mesh iterations, one per second)
; so string1 logs for a maximum of 5/(1.5) => ~3 times and string2 logs only once
{Do(test1)}
{Do(test1)}
{Do(test1)}
{Do(test1)}
{Do(test1)}

; Setup
@wire(test2 {
  Once({
    0 >= counter
    counter | Log("counter set to 0 only once")
    ; => 0
  })

  Math.Inc(counter)
  counter | Log("counter incremented every time wire executes")
  ; => 1, 2, 3, 4, 5
})

{Do(test2)}
{Do(test2)}
{Do(test2)}
{Do(test2)}
{Do(test2)}

[info] [test1] Hello World, every 1.5s during a wire flow execution
[info] [test1] Hello World, once during every wire flow execution
[info] [test2] counter set to 0 only once: 0
[info] [test2] counter incremented every time wire executes: 1
[info] [test2] counter incremented every time wire executes: 2
[info] [test2] counter incremented every time wire executes: 3
[info] [test2] counter incremented every time wire executes: 4
[info] [test2] counter incremented every time wire executes: 5

 

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