# Uibuilder - passing variables from node-red to frontend

**URL:** https://discourse.nodered.org/t/uibuilder-passing-variables-from-node-red-to-frontend/93327
**Category:** General
**Tags:** uibuilder
**Created:** [21 November 2024 23:07 UTC](https://discourse.nodered.org/t/uibuilder-passing-variables-from-node-red-to-frontend/93327 "2024-11-21T23:07:56Z")
**Posts on this page:** 4
**Page:** 1

<div class="post-metadata">

### Author: ![skytrackerdave](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/skytrackerdave/32/95810_2.png) [@skytrackerdave](https://discourse.nodered.org/u/skytrackerdave)
#### Post date: [21 November 2024 23:07 UTC](https://discourse.nodered.org/t/uibuilder-passing-variables-from-node-red-to-frontend/93327/1 "2024-11-21T23:07:56Z")

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Imagine the following in a webpage;

```auto
<script>
    var myvar = 'foobar';
</script>

```

Now I would like to change that variable from Node-red - uibuilder. Is there a way to do this?  
I have reviewed much of the documentation and videos and most of it concerns inserting and updating sections of the webpage that are visible.

Can I send a variable from Node-red or modify a variable that already exists?

---

<div class="post-metadata">

### Author: ![TotallyInformation](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/totallyinformation/32/31_2.png) [@TotallyInformation](https://discourse.nodered.org/u/TotallyInformation)
#### Post date: [21 November 2024 23:48 UTC](https://discourse.nodered.org/t/uibuilder-passing-variables-from-node-red-to-frontend/93327/2 "2024-11-21T23:48:36Z")

</div>

> [@skytrackerdave](#):
>
> Is there a way to do this?

Have faith! There is _always_ a way with UIBUILDER. 😄

> [@skytrackerdave](#):
>
> Can I send a variable from Node-red or modify a variable that already exists?

Absolutely. Here is the classic method:

```js
let myvar = 'foobar'
uibuilder.onChange('msg', (msg) => {
  myvar = msg.payload
})

```

You could also use onTopic instead of onChange if you prefer.

---

<div class="post-metadata">

### Author: ![skytrackerdave](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/skytrackerdave/32/95810_2.png) [@skytrackerdave](https://discourse.nodered.org/u/skytrackerdave)
#### Post date: [22 November 2024 16:47 UTC](https://discourse.nodered.org/t/uibuilder-passing-variables-from-node-red-to-frontend/93327/4 "2024-11-22T16:47:57Z")

</div>

Works! Thank you.

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<div class="post-metadata">

### Author: ![system](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/1X/d073cd938eafa2e558d7c2cd59003b3ef4963033.png) [@system](https://discourse.nodered.org/u/system)
#### Post date: [6 December 2024 16:48 UTC](https://discourse.nodered.org/t/uibuilder-passing-variables-from-node-red-to-frontend/93327/5 "2024-12-06T16:48:57Z")

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