VK Bridge Core

Usage

``js
import bridge from '@vkontakte/vk-bridge';

// Sends event to client
bridge.send('VKWebAppInit');

// Subscribes to event, sended by client
bridge.subscribe((e) => console.log(e));
`

For use in a browser, include the file dist/browser.min.js and use as follows

`html



`

API Reference

$3

Sends a message to native client and returns the Promise object with response data

Parameters

- method _required_ The VK Bridge method
- params _optional_ Message data object

Example

`js
// Sending event to client
bridge
.send('VKWebAppGetEmail')
.then((data) => {
// Handling received data
console.log(data.email);
})
.catch((error) => {
// Handling an error
});
`

You can also use imperative way

`js
try {
const data = await bridge.send('VKWebAppGetEmail');

// Handling received data
console.log(data.email);
} catch (error) {
// Handling an error
}
`

$3

Subscribes a function to events listening

Parameters

- fn _required_ Function to be subscribed to events

Example

`js
// Subscribing to receiving events
bridge.subscribe((event) => {
if (!event.detail) {
return;
}

const { type, data } = event.detail;

if (type === 'VKWebAppOpenCodeReaderResult') {
// Reading result of the Code Reader
console.log(data.code_data);
}

if (type === 'VKWebAppOpenCodeReaderFailed') {
// Catching the error
console.log(data.error_type, data.error_data);
}
});

// Sending method
bridge.send('VKWebAppOpenCodeReader', {});
`

$3

Unsubscribes a function from events listening

Parameters

- fn _required_ Event subscribed function

Example

`js
const fn = (event) => {
// ...
};

// Subscribing
bridge.subscribe(fn);

// Unsubscribing
bridge.unsubscribe(fn);
`

$3

Checks if an event is available on the current device

Parameters

- method _required_ The VK Bridge method

$3

Returns true if VK Bridge is running in mobile app, or false if not

$3

Returns true if VK Bridge is running in iframe, or false if not

$3

Returns true if VK Bridge is running in embedded app, or false if not

$3

Returns true if VK Bridge is running in standalone app, or false if not

Middleware API

_Middlewares_ are pieces of code that intercept and process data between sending and receiving. Thus, by creating middlewares, you can easily log data, modify data before sending it, talking to an asynchronous API, etc. If you've used Redux, you were also probably already familiar with the concept—a similar is used here.

$3

Creates the VK Bridge enhancer that applies middleware to the send
method. This is handy for a variety of task such as logging every sent
event. Returns the VK Bridge enhancer applying the middleware.

Parameters

- middlewareN A middleware to be applied

Example

`js
import bridge, { applyMiddleware } from '@vkontakte/vk-bridge';

// Logs the result of each sent event
const logger =
({ send, subscribe }) =>
(next) =>
async (method, props) => {
const result = await next(method, props);
console.log(result);
return result;
};

const enhancedBridge = applyMiddleware(logger)(bridge);
`

Functions

$3

Parse URL search params for get provided to mini app launch params.

Parameters

- urlSearchParams a.k.a window.location.search.

Example

`js
import { parseURLSearchParamsForGetLaunchParams } from '@vkontakte/vk-bridge';

// https://exmample-mini-app.io/?vk_platform=desktop_web&vk_is_app_user=1&vk_user_id=12345
const { vk_platform, vk_viewer_group_role, vk_user_id } = parseURLSearchParamsForGetLaunchParams(
window.location.search,
);

console.log(vk_platform); // 'desktop_web'
console.log(vk_is_app_user); // 1
console.log(vk_user_id); // 12345
``