index.uts

import {
    Emitter,
    getCurrentMP
} from '@dcloudio/uni-runtime'
import {
    $Emit,
    $Off,
    $On,
    $Once,
} from '../interface.uts'
import {
    API_$_EMIT,
    API_$_OFF,
    API_$_ON,
    API_$_ONCE,
} from '../protocol.uts'

interface IUniEventEmitter {
    on: (eventName: string, callback: Function) => void
    once: (eventName: string, callback: Function) => void
    off: (eventName: string, callback?: Function | null) => void
    emit: (eventName: string, ...args: (Object | undefined | null)[]) => void
}

const emitterStore = new Map<string, IUniEventEmitter>()

function getEmitter(): IUniEventEmitter {
    const mp = getCurrentMP()
    const id = mp.id as string
    if (emitterStore.has(id)) {
        return emitterStore.get(id) as IUniEventEmitter
    }
    const emitter = new Emitter() as IUniEventEmitter
    emitterStore.set(id, emitter)
    mp.on('beforeClose', () => {
        emitterStore.delete(id)
    })
    return emitter
}

export const $on: $On = defineSyncApi<number>(
    API_$_ON,
    (eventName: string, callback: Function) => {
        return getEmitter().on(eventName, callback)
    }
) as $On

export const $once: $Once = defineSyncApi<number>(
    API_$_ONCE,
    (eventName: string, callback: Function) => {
        return getEmitter().once(eventName, callback)
    }
) as $Once

export const $off: $Off = defineSyncApi<void>(
    API_$_OFF,
    (eventName: string, callback: Function) => {
        getEmitter().off(eventName, callback)
    }
) as $Off

export const $emit: $Emit = defineSyncApi<void>(
    API_$_EMIT,
    (eventName: string, ...args: (Object | undefined | null)[]) => {
        getEmitter().emit(eventName, ...args)
    }
) as $Emit