@benshi.ai/js-sdk/src/core/BsAppStateMonitor.ts

Benshi SDK

import isBrowser from "is-in-browser";

import { 
    listenApplicationClose, 
    listenApplicationVisibilityChange, 
    listenPageChanged, 
    listenPageScrolled 
} from "../drivers/BsSystem";
import BsLog from "../modules/BsLog";
import Navigation from "../modules/Navigation";
import { AppAction, AppProperties, PageProperties } from "../modules/Navigation/typings";

let lastPageChangeTimestamp = null

let currentPageURL = ''
let currentTitle = ''

const logOpenAppEvent = () => {
    lastPageChangeTimestamp = new Date()
    currentPageURL = window.location.href
    currentTitle = document.title

    const perfEntries = performance.getEntriesByType("navigation");

    const appProperties: AppProperties = {
        action: AppAction.Open,
        start_time: Math.round((typeof perfEntries[0] === 'undefined') ? 0 : perfEntries[0].duration)
    }

    Navigation.logAppEvent(appProperties)
}

const logBackgroundEvent = () => {
    const appProperties: AppProperties = {
        action: AppAction.Background,
        start_time: 0
    }

    Navigation.logAppEvent(appProperties)
}


const logResumeEvent = () => {
    const appProperties: AppProperties = {
        action: AppAction.Resume,
        start_time: 0
    }

    Navigation.logAppEvent(appProperties)
}

const logPageChangedEvent = (path, title) => {
    const currentTimestamp = Date.now()
    const duration = Math.round((currentTimestamp - lastPageChangeTimestamp) / 1000)

    const properties: PageProperties = {
        path,
        title,
        duration
    }

    lastPageChangeTimestamp = currentTimestamp
    Navigation.logPageEvent(properties)
}

const logPageCompletedEvent = (path, title) => {

    const properties: PageProperties = {
        path,
        title,
    }

    Navigation.logPageEvent(properties)
}


export const init = (bslog: BsLog) => {

    if (!isBrowser) {
        return
    }

    const PAGE_COMPLETED_SCROLL_THRESHOLD = 90
    let lastCompletedPageTracked = ''

    // This function is called just once, so
    // it is a good point to log the open event
    // Previous implementation relied this on
    // navigator listeners, but I did not find
    // a homogenous behaviour across browsers
    logOpenAppEvent()

    listenApplicationClose(() => {
        // console.warn('application is about to close: ', document.visibilityState)
        // bslog.flush()
    })

    listenApplicationVisibilityChange(logResumeEvent, logBackgroundEvent)

    listenPageChanged((path, title) => {
        lastCompletedPageTracked=''

        logPageChangedEvent(currentPageURL, currentTitle)

        currentPageURL = path
        currentTitle = title
    })

    listenPageScrolled(PAGE_COMPLETED_SCROLL_THRESHOLD, (scrollPercent) => {
        if (lastCompletedPageTracked !== document.location.href) {

            console.warn('triggering 90% completed paged!')
        }

        lastCompletedPageTracked = document.location.href
    })
}

export default init