This document describes requirements that an application must fulfill in order to provide a proper environment for Dapps running inside a browser. A description of the Status Dapp API is provided, along with an overview of bidirectional communication underlying the API implementation. The document also includes a list of EIPs that this API implements.
| **Ethereum Provider** | A JS object (`window.ethereum`) injected into each web page opened in the browser providing web3 compatible provider. |
| **Bridge** | A set of facilities allow bidirectional communication between JS code and the application. |
## Overview
The application should expose an Ethereum Provider object (`window.ethereum`) to JS code running inside the browser. It is important to have the `window.ethereum` object available before the page loads, otherwise Dapps might not work correctly.
Additionally, the browser component should also provide bidirectional communication between JS code and the application.
## Usage in Dapps
Dapps can use the below properties and methods of `window.ethereum` object.
### Properties
#### `isStatus`
Returns true. Can be used by the Dapp to find out whether it's running inside Status.
#### `status`
Returns a `StatusAPI` object. For now it supports one method: `getContactCode` that sends a `contact-code` request to Status.
### Methods
#### `isConnected`
Similarly to Ethereum JS API [docs](https://github.com/ethereum/wiki/wiki/JavaScript-API#web3isconnected), it should be called to check if connection to a node exists. On Status, this fn always returns true, as once Status is up and running, node is automatically started.
#### `scanQRCode`
Sends a `qr-code` Status API request.
#### `request`
`request` method as defined by EIP-1193.
### Unused
Below are some legacy methods that some Dapps might still use.
#### `enable` (DEPRECATED)
Sends a `web3` Status API request. It returns a first entry in the list of available accounts.
Legacy `enable` method as defined by [EIP1102](https://github.com/ethereum/EIPs/blob/master/EIPS/eip-1102.md).
#### `send` (DEPRECATED)
Legacy `send` method as defined by [EIP1193](https://github.com/ethereum/EIPs/blob/master/EIPS/eip-1193.md).
#### `sendAsync` (DEPRECATED)
Legacy `sendAsync` method as defined by [EIP1193](https://github.com/ethereum/EIPs/blob/master/EIPS/eip-1193.md).
#### `sendSync` (DEPRECATED)
Legacy `send` method.
## Implementation
Status uses a [forked version](https://github.com/status-im/react-native-webview) of [react-native-webview](https://github.com/react-native-community/react-native-webview) to display web or dapps content. The fork provides an Android implementation of JS injection before page load. It is required in order to properly inject Ethereum Provider object.
- [webview.js](https://github.com/status-im/status-react/blob/develop/resources/js/webview.js): override for `history.pushState` used internally
Dapps running inside a browser communicate with Status Ethereum node by means of a *bridge* provided by react-native-webview library. The bridge allows for bidirectional communication between browser and Status. In order to do so, it injects a special `ReactNativeWebview` object into each page it loads.
On Status (React Native) end, `react-native-webview` library provides `WebView.injectJavascript` function on a webview component that allows to execute arbitrary code inside the webview. Thus it is possible to inject a function call passing Status node response back to the Dapp.
Below is the table briefly describing what functions/properties are used. More details available in package [docs](https://github.com/react-native-community/react-native-webview/blob/master/docs/Guide.md#communicating-between-js-and-native).
- [EIP1102](https://github.com/ethereum/EIPs/blob/master/EIPS/eip-1102.md): `eth_requestAccounts` support
- [EIP1193](https://github.com/ethereum/EIPs/blob/master/EIPS/eip-1193.md): `connect`, `disconnect`, `chainChanged`, and `accountsChanged` event support is not implemented
