# callback

## Description

Triggers a flow of actions.

## Input / Parameter

| Name  | Description                                           | Input Type | Default | Options | Required |
| ----- | ----------------------------------------------------- | ---------- | ------- | ------- | -------- |
| extra | The stored value that is passed to all the callbacks. | Any        | -       | -       | No       |

## Output

| Description                        | Output Type |
| ---------------------------------- | ----------- |
| Returns the formatted information. | Object      |

## Callback

### yesCallback

The functions to be executed.

## Example

In this example, we will put callback inside `Log.write` function.

### Steps

1. Drag a `button` component into the canvas and open the `Action` tab. Select the `press` event of the button and drag the `Log.write` function to the event flow.

   ![](https://399701567-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FwmJ1RKjM2uNFaL6fO3Xu%2Fuploads%2Fgit-blob-e553498134e20b2174447f1e6d2722d2b6a49aec%2Fcallback-step-1.png?alt=media)
2. Change the `Log.write` value into function.

   ![](https://399701567-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FwmJ1RKjM2uNFaL6fO3Xu%2Fuploads%2Fgit-blob-975038d872660cd95ceafb0fb162c5c34e2c1c33%2Fcallback-step-2.png?alt=media)
3. Put `Control.callback` function inside and under yes callback, call `Log.write` or any function(s) that required to call.

   ![](https://399701567-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FwmJ1RKjM2uNFaL6fO3Xu%2Fuploads%2Fgit-blob-bfd576afa6b151c4cb1428d4233dc5f8d8b244f3%2Fcallback-step-3.png?alt=media)

### Result

1. The function will call yes callback(s) that specified under the `Control.callback` function.

   ![](https://399701567-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FwmJ1RKjM2uNFaL6fO3Xu%2Fuploads%2Fgit-blob-0ce0bfbe9066baf56b59794fbd9cb569e03df23f%2Fcallback-result.png?alt=media)