# Arbitrary, multiple synchronous message function?

**URL:** <https://discourse.nodered.org/t/arbitrary-multiple-synchronous-message-function/10818>\
**Category:** General\
**Created:** [4 May 2019 20:59 UTC](https://discourse.nodered.org/t/arbitrary-multiple-synchronous-message-function/10818 "2019-05-04T20:59:41Z")\
**Posts on this page:** 11\
**Page:** 1

<div class="post-metadata">

**Author:** ![yesdred](https://avatars.discourse-cdn.com/v4/letter/y/e274bd/32.png) [@yesdred](https://discourse.nodered.org/u/yesdred)\
**Post date:** [4 May 2019 20:59 UTC](https://discourse.nodered.org/t/arbitrary-multiple-synchronous-message-function/10818/1 "2019-05-04T20:59:41Z")

</div>

I'd like to trigger a flow x times where x == msg.payload. Due to the inherent asynchronicity, the following function fails:

```auto
var count = parseInt(msg.payload);
var i = 0;
while ( i < count) {
    i++;
    node.send(msg);
}

```

What am I missing?

---

<div class="post-metadata">

**Author:** ![dceejay](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/dceejay/32/38_2.png) [@dceejay](https://discourse.nodered.org/u/dceejay)\
**Post date:** [4 May 2019 21:05 UTC](https://discourse.nodered.org/t/arbitrary-multiple-synchronous-message-function/10818/2 "2019-05-04T21:05:48Z")

</div>

How is it failing ?

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<div class="post-metadata">

**Author:** ![Steve-Mcl](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/steve-mcl/32/4826_2.png) [@Steve-Mcl](https://discourse.nodered.org/u/Steve-Mcl)\
**Post date:** [4 May 2019 21:07 UTC](https://discourse.nodered.org/t/arbitrary-multiple-synchronous-message-function/10818/3 "2019-05-04T21:07:29Z")

</div>

It looks ok.

Are you certain payload contains a number? Add a debug to output of node before this node to check

---

<div class="post-metadata">

**Author:** ![knolleary](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/knolleary/32/3_2.png) [@knolleary](https://discourse.nodered.org/u/knolleary)\
**Post date:** [4 May 2019 21:58 UTC](https://discourse.nodered.org/t/arbitrary-multiple-synchronous-message-function/10818/4 "2019-05-04T21:58:43Z")

</div>

One way it _could_ be failing is that you are sending the same msg object multiple times. As JavaScript passes references around, if your flow modifies the msg object, you'll find all instances of the msg have modified.

The runtime clones messages to avoid this, but it also tried to avoid doing so if it can to avoid that overhead. Calling node.send multiple times like that stops the runtime from detecting it needs to do the clone thing.

You can do it yourself with:

```auto
node.send(RED.util.cloneMessage(msg));

```

(It might be `RED.utils` rather than `RED.util` - I can never remember and I'm not in a place to check)

---

<div class="post-metadata">

**Author:** ![yesdred](https://avatars.discourse-cdn.com/v4/letter/y/e274bd/32.png) [@yesdred](https://discourse.nodered.org/u/yesdred)\
**Post date:** [4 May 2019 22:37 UTC](https://discourse.nodered.org/t/arbitrary-multiple-synchronous-message-function/10818/5 "2019-05-04T22:37:04Z")

</div>

When the payload is "4" I get four messages at once that don't get individually delayed by the following delay node.

---

<div class="post-metadata">

**Author:** ![yesdred](https://avatars.discourse-cdn.com/v4/letter/y/e274bd/32.png) [@yesdred](https://discourse.nodered.org/u/yesdred)\
**Post date:** [4 May 2019 22:37 UTC](https://discourse.nodered.org/t/arbitrary-multiple-synchronous-message-function/10818/6 "2019-05-04T22:37:56Z")

</div>

The payload is a string and it get's converted to a number.

---

<div class="post-metadata">

**Author:** ![yesdred](https://avatars.discourse-cdn.com/v4/letter/y/e274bd/32.png) [@yesdred](https://discourse.nodered.org/u/yesdred)\
**Post date:** [4 May 2019 22:42 UTC](https://discourse.nodered.org/t/arbitrary-multiple-synchronous-message-function/10818/7 "2019-05-04T22:42:00Z")

</div>

Thanks for the hint. I tried it but it doesn't help. The following delay node does not treat the input as individual messages.

`[{"id":"acf0af31.be2a58","type":"function","z":"e4c2ecf.f5a731","name":"convert to int","func":"var count = parseInt(msg.payload);\nvar i = 0;\nwhile ( i < count) {\n i++;\n node.send(RED.util.cloneMessage(msg));\n}\n","outputs":1,"noerr":0,"x":280,"y":79,"wires":[["15a88035.337758"]]},{"id":"15a88035.337758","type":"delay","z":"e4c2ecf.f5a731","name":"","pauseType":"delay","timeout":"1","timeoutUnits":"seconds","rate":"1","nbRateUnits":"1","rateUnits":"second","randomFirst":"1","randomLast":"5","randomUnits":"seconds","drop":false,"x":457,"y":80,"wires":[["bd8e4edf.3d7908"]]},{"id":"bd8e4edf.3d7908","type":"debug","z":"e4c2ecf.f5a731","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","x":629,"y":80,"wires":[]},{"id":"cadffe6.e1fe","type":"inject","z":"e4c2ecf.f5a731","name":"","topic":"","payload":"4","payloadType":"str","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":139,"y":79,"wires":[["acf0af31.be2a58"]]}]`

---

<div class="post-metadata">

**Author:** ![Steve-Mcl](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/steve-mcl/32/4826_2.png) [@Steve-Mcl](https://discourse.nodered.org/u/Steve-Mcl)\
**Post date:** [4 May 2019 23:01 UTC](https://discourse.nodered.org/t/arbitrary-multiple-synchronous-message-function/10818/8 "2019-05-04T23:01:09Z")

</div>

> [@yesdred](#):
>
> When the payload is "4" I get four messages at once that don't get individually delayed by the following delay node

You never mentioned a delay. And yes you will get 4 messages almost instantaneously.

If you use a delay with rate limit that may achieve what you want?

---

<div class="post-metadata">

**Author:** ![Steve-Mcl](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/steve-mcl/32/4826_2.png) [@Steve-Mcl](https://discourse.nodered.org/u/Steve-Mcl)\
**Post date:** [4 May 2019 23:03 UTC](https://discourse.nodered.org/t/arbitrary-multiple-synchronous-message-function/10818/9 "2019-05-04T23:03:22Z")

</div>

For clarity, the delay (as a delay) will delay the messages for the specified time.

So if you have a delay of 5 sec, and send 4 messages at once, all 4 will be delayed for 5 secs then be sent pretty much 5 secs later (i.e. together 5secs after they arrived).

---

<div class="post-metadata">

**Author:** ![Steve-Mcl](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/steve-mcl/32/4826_2.png) [@Steve-Mcl](https://discourse.nodered.org/u/Steve-Mcl)\
**Post date:** [4 May 2019 23:08 UTC](https://discourse.nodered.org/t/arbitrary-multiple-synchronous-message-function/10818/10 "2019-05-04T23:08:01Z")

</div>

Rate limited

```auto
[{"id":"171282d9.1e907d","type":"function","z":"f57e8780.400c68","name":"convert to int","func":"var count = parseInt(msg.payload);\nvar i = 0;\nwhile ( i < count) {\n i++;\n node.send(RED.util.cloneMessage(msg));\n}\n","outputs":1,"noerr":0,"x":250,"y":80,"wires":[["f8c02a35.5ffc88"]]},{"id":"f8c02a35.5ffc88","type":"delay","z":"f57e8780.400c68","name":"","pauseType":"rate","timeout":"1","timeoutUnits":"seconds","rate":"1","nbRateUnits":"1","rateUnits":"second","randomFirst":"1","randomLast":"5","randomUnits":"seconds","drop":false,"x":437,"y":81,"wires":[["7875db2f.d59244"]]},{"id":"7875db2f.d59244","type":"debug","z":"f57e8780.400c68","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","x":599,"y":81,"wires":[]},{"id":"62a807c4.d8c528","type":"inject","z":"f57e8780.400c68","name":"","topic":"","payload":"4","payloadType":"str","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":109,"y":80,"wires":[["171282d9.1e907d"]]}]

```

---

<div class="post-metadata">

**Author:** ![yesdred](https://avatars.discourse-cdn.com/v4/letter/y/e274bd/32.png) [@yesdred](https://discourse.nodered.org/u/yesdred)\
**Post date:** [5 May 2019 06:26 UTC](https://discourse.nodered.org/t/arbitrary-multiple-synchronous-message-function/10818/11 "2019-05-05T06:26:03Z")

</div>

Thanks, Steve. I feel embarrassed. Sorry for the post. Rate limiting, of course, leads to the wanted result.