# Commands

## Overview

![](https://3504352165-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FW0UCgeNLp5UrqOZTjvsN%2Fuploads%2F4aUdn5VnTlBfawOnAq68%2Fcommands.svg?alt=media\&token=229ae843-709c-4e65-9802-fabe1931926e)

Commands are issued from the parent window (your website) to the JavaScript API. The API then relays the command via `window.postMessage()` to the iframed flipbook.

## Flipbook-related commands

### `updateEventSettings`

It is possible to dictate how the iframed flipbook should handle events when they have been triggered. The method accepts a single argument that is an object containing the following keys, which references events that the v2 Flipbook API listens to:

* [`onBasketClick`](https://docs.ipaper.io/flipbook-javascript-api/events#onbasketclick)
* [`onItemAdd`](https://docs.ipaper.io/flipbook-javascript-api/events#onitemadd)

The keys should contain an object of the following format: `{ preventDefault: <boolean> }`, where `<boolean>` is `true` or `false`. When `preventDefault` is set to `true`, the flipbook will skip the default action associated with each event. If set to `false`, the default action will be performed.

| Event                                                                                  | Default action taking place in the flipbook                                                                             |
| -------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------- |
| [`onBasketClick`](https://docs.ipaper.io/flipbook-javascript-api/events#onbasketclick) | Opens the shop basket                                                                                                   |
| [`onItemAdd`](https://docs.ipaper.io/flipbook-javascript-api/events#onitemadd)         | <p>Adds the item to the shop basket.<br>Triggered by any enrichment that adds a shop item (e.g. shop variant menu).</p> |

An example use:

```javascript
// Disable opening of shop basket AND adding shop items
iPaperAPI.updateEventSettings({
	onBasketClick: { preventDefault: true },
	onItemAdd: { preventDefault: true }
});
```

## Publication-related commands

### `goToPage`

Navigate to a specific page: the page number is to be provided as the one and only argument of the function. For example:

```javascript
iPaperAPI.goToPage(4);
```

### `goToPreviousPage`

Go to the previous spread (if flipbook has a spread-based layout), or the previous page (if flipbook has a page-based layout). This method accepts no arguments:

```javascript
iPaperAPI.goToPreviousPage();
```

### `goToNextPage`

Go to the next spread (if flipbook has a spread-based layout), or the next page (if flipbook has a page-based layout). This method accepts no arguments:

```javascript
iPaperAPI.goToNextPage();
```

## Shop-related commands

### `addItem`

Programmatically adds a custom item to the basket. This method accepts a single argument, consisting of properties of the shop item entity.

| Property      | Type     | Description                                |
| ------------- | -------- | ------------------------------------------ |
| `title`       | `string` | Shop item title                            |
| `description` | `string` | Shop item description                      |
| `productID`   | `string` | Shop item product ID                       |
| `originPage`  | `number` | Page number where the shop item is located |
| `price`       | `number` | Shop item price                            |
| `quantity`    | `number` | Number of items added                      |

Example use:

```javascript
iPaperAPI.addItem({
    title: 'My product',
    description: 'Product description',
    productID: 'PROD-25B',
    price: '29.95',
    originPage: 6,
    quantity: 1
});
```

## Advanced use

If you are accustomed to the `.trigger()` regime (such as that implemented in JQuery), you can also use it as such:

```javascript
iPaperAPI.trigger('goToPage', 4);
```

Refer to [**Event listeners and command triggers**](https://docs.ipaper.io/flipbook-javascript-api/advanced-usage#event-listeners-and-command-triggers) on the advanced usage page for a wholesome example.