> For the complete documentation index, see [llms.txt](https://docs.apryse.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.apryse.com/reusable-content/guide/guide-gs-reactnative-addapi1.md).

# guide/gs/reactNative/addAPI1

***

### Introduction

The React Native API for Apryse Mobile SDK includes all of the most used functions and methods for viewing, annotating and saving PDF documents. However, it is possible your app may need access to APIs that are available as part of the native API, but are not directly available to React Native.

This guide provides an example of how to add the following to the React Native interface:

* `pageChangeOnTap` prop that determines whether page will turn left or right when tapping corresponding edges.
* `getField` function which retrieves information about a field using its name.
* `onLayoutChanged` event listener that is raised when the layout of viewer has changed.

You can follow the same pattern to add new functions and props that your React Native app may need. The new additions could be simple ones, which expose one piece of functionality, or custom ones, that expose a series of native commands under the hood.

Prior to following this guide, we highly recommend you to go through the official guide here: [Native UI Components](https://reactnative.dev/docs/native-components-android/) to have a better understanding of the system.

#### 1. Fork and clone Apryse's React Native Repo

The source is hosted on GitHub here: [https://github.com/ApryseSDK/pdftron-react-native](https://github.com/ApryseSDK/pdftron-react-native/)

Fork the project and clone a copy of the repository to your disk.

### Adding the `pageChangeOnTap` prop

#### 2. Add prop to DocumentView\.tsx interface file

The `DocumentView.tsx` interface file lists all of the React Native props on the DocumentView component.

Add the prop declaration:

```js
static propTypes = {
  pageChangeOnTap: PropTypes.bool,
};
```

For props that accept `Config` constants or arrays of `Config` constants, use the `oneOf` and `arrayOf` helper methods. These helpers return flexible types that allow custom checks for TypeScript users, while maintaining standard run-time checks for all users.


---

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