Files
tauri/tooling/api/src/event.ts
2022-06-12 21:44:33 -03:00

88 lines
2.6 KiB
TypeScript

// Copyright 2019-2021 Tauri Programme within The Commons Conservancy
// SPDX-License-Identifier: Apache-2.0
// SPDX-License-Identifier: MIT
/**
* The event system allows you to emit events to the backend and listen to events from it.
*
* This package is also accessible with `window.__TAURI__.event` when `tauri.conf.json > build > withGlobalTauri` is set to true.
* @module
*/
import * as eventApi from './helpers/event'
import type {
EventName,
EventCallback,
UnlistenFn,
Event
} from './helpers/event'
/**
* Listen to an event from the backend.
* @example Listen to the `error` event expecting a string payload
* ```typescript
* import { listen } from '@tauri-apps/api/event';
* const unlisten = await listen<string>('error', (event) => {
* console.log(`Got error in window ${event.windowLabel}, payload: ${payload}`);
* });
*
* // removes the listener later
* await unlisten();
* ```
*
* @param event Event name. Must include only alphanumeric characters, `-`, `/`, `:` and `_`.
* @param handler Event handler callback.
* @return A promise resolving to a function to unlisten to the event.
*/
async function listen<T>(
event: EventName,
handler: EventCallback<T>
): Promise<UnlistenFn> {
return eventApi.listen(event, null, handler)
}
/**
* Listen to an one-off event from the backend.
* @example Listen to the `loaded` event that is only triggered once
* ```typescript
* import { once } from '@tauri-apps/api/event';
* interface LoadedPayload {
* loggedIn: boolean,
* token: string
* }
* const unlisten = await once<LoadedPayload>('loaded', (event) => {
* console.log(`App is loaded, logggedIn: ${event.payload.loggedIn}, token: ${event.payload.token}`);
* });
* ```
*
* @param event Event name. Must include only alphanumeric characters, `-`, `/`, `:` and `_`.
* @param handler Event handler callback.
* @returns A promise resolving to a function to unlisten to the event.
*/
async function once<T>(
event: EventName,
handler: EventCallback<T>
): Promise<UnlistenFn> {
return eventApi.once(event, null, handler)
}
/**
* Emits an event to the backend.
* @example Emits the `frontend-loaded` event with the given payload
* ```typescript
* import { emit } from '@tauri-apps/api/event';
* await emit('frontend-loaded', { loggedIn: true, token: 'authToken' });
* ```
*
* @param event Event name. Must include only alphanumeric characters, `-`, `/`, `:` and `_`.
* @param [payload] Event payload
* @returns
*/
async function emit(event: string, payload?: unknown): Promise<void> {
return eventApi.emit(event, undefined, payload)
}
export type { Event, EventName, EventCallback, UnlistenFn }
export { listen, once, emit }