---
hide_title: true
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title: Script node
---

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# Script

This node allows you to add complex JavaScript to your application.
Please refer to the [Script Guide](/docs/guides/business-logic/javascript) to learn more about the API.
But remember - with great power comes great responsibility.

<div className="ndl-image-with-background l">

![](/nodes/javascript/script/script.png)

</div>

In most cases you are better off using the simpler <span className="ndl-node">[Function](/nodes/javascript/function)</span> node for your custom JavaScript.

## Getting Started

Reading the Javascript [guide](/docs/guides/business-logic/javascript) gives a broader understanding of how it works.

Here is an example of how you create a function that you can call in the node graph:

```js
Script.Inputs = {
  Prefix: "string",
  Value: "number"
};

Script.Outputs = {
  Done: "signal",
  Value: "string",
};

Script.Signals.MyFunction = function (value) {
  // run javascript code
  
  Script.Outputs.Value = Script.Inputs.Prefix + " " + Script.Inputs.Value;
  Script.Outputs.Done();
};
```

This can also be done with a setter so you dont have to call the `MyFunction` signal.

```js
Script.Inputs = {
  Prefix: "string",
  Value: "number"
};

Script.Outputs = {
  Done: "signal",
  Value: "string",
};

function onChange() {
  Script.Outputs.Value = Script.Inputs.Prefix + " " + Script.Inputs.Value;
  Script.Outputs.Done();
}

Script.Setters.Prefix = onChange;
Script.Setters.Value = onChange;
```

### Handling when the node is unmounted

When the node is unmounted like going to a different page, the `OnDestroy` method will be called.
In this method, you can clean up potential listeners or libraries to keep the app performant.

```js
Script.OnDestroy = function () {
  // called when the node is unmounted
}
```

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## Inputs

The inputs are defined by the content of the script or by explicitly specifying inputs in the properties.
See the javascript [guide](/docs/guides/business-logic/javascript) for more details.

## Outputs

The outputs are defined by the content of the script or by explicitly specifying outputs in the properties.
See the javascript [guide](/docs/guides/business-logic/javascript) for more details.