freesewing/sites/dev/docs/reference/api/pattern/on/readme.mdx

---
title: Pattern.on()
---

The `Pattern.on()` method allows you to attach a function to one of the
pattern's [lifecycle hooks](/reference/hooks/). It takes the
lifecycle hook's name as the first argument and the function as the second.
This method will then be triggered by the lifecycle hook.

:::note
This method is chainable as it returns the Pattern object
:::

## Pattern.on() signature

```js
Pattern pattern.on(string hook, function method)
```

:::tip

Refer to [the Lifecycle hooks documentation](/reference/hooks/) for a list
of all available lifecycle hooks, as well as the signature of the function you
should pass it.

:::

## Pattern.on() example

```js
pattern.on('preRender', function (svg) {
  svg.style += 'svg { background: yellow;}'
})
```

Your pattern now has a yellow background.

:::tip

The [plugin guide](/guides/plugins/) contains more info on how you can use hooks

:::