firebase cloud message (FCM) example

fcm.js

/**
 *
 * @authors Ted Shiu (ted@sitetag.us)
 * @date    2016-12-15 17:29:18
 */

var config = {
    apiKey: '',
    authDomain: '',
    databaseURL: '',
    storageBucket: '',
    messagingSenderId: ''
};
firebase.initializeApp(config);

var messaging = firebase.messaging();


messaging.onTokenRefresh(function() {
    messaging.getToken().then(function(refreshedToken) {
        console.log('Token refreshed.');
        setTokenSentToServer(false);
        // Send Instance ID token to app server.
        sendTokenToServer(refreshedToken);
    }).catch(function(err) {
        console.log('Unable to retrieve refreshed token ', err);
    });
});

messaging.onMessage(function(payload) {
    console.log("Message received. ", payload);
    fcmFgUI(payload);
});

function initToken() {
    messaging.getToken().then(function(currentToken) {
        if (currentToken) {
            sendTokenToServer(currentToken);
        } else {
            console.log('No Instance ID token available. Request permission to generate one.');
            permissionRequiredUI();
            setTokenSentToServer(false);
        }
    }).catch(function(err) {
        console.log('An error occurred while retrieving token. ', err);
        setTokenSentToServer(false);
    });
}

function sendTokenToServer(currentToken) {
    if (!isTokenSentToServer()) {
        console.log('Sending token to server...');
        // TODO(developer): Send the current token to your server.
        // get old token
        // api del old token
        // api metch
        setTokenSentToServer(true);
        // senf topic api to app server
        subTopic();
    } else {
        console.log('Token already sent to server so won\'t send it again unless it changes');
    }
}

function requestPermission() {
    console.log('Requesting permission...');
    messaging.requestPermission().then(function() {
        initToken();
    }).catch(function(err) {
        console.log('Unable to get permission to notify.', err);
    });
}

function deleteToken() {
    messaging.getToken().then(function(currentToken) {
        messaging.deleteToken(currentToken).then(function() {
            console.log('Token deleted.');
            setTokenSentToServer(false);
            initToken();
        }).catch(function(err) {
            console.log('Unable to delete token. ', err);
        });
    }).catch(function(err) {
        console.log('Error retrieving Instance ID token. ', err);
    });
}


function fcmFgUI(payload) {
    console.log(payload);
    // TODO
    // {
    //   "from": "1021059308181",
    //   "collapse_key": "do_not_collapse",
    //   "notification": {
    //     "title": "this is title",
    //     "body": "Enter content",
    //     "icon": "demo/fcm/quickstart-js/messaging/firebase-logo.png",
    //     "click_action": "http://tedshd.io"
    //   }
    // }
}

function subTopic() {
    // TODO
}

function permissionRequiredUI() {
    // TODO
}

function isTokenSentToServer() {
    if (window.localStorage.getItem('sentToServer') == 1) {
        return true;
    }
    return false;
}

function setTokenSentToServer(sent) {
    if (sent) {
        window.localStorage.setItem('sentToServer', 1);
    } else {
    window.localStorage.setItem('sentToServer', 0);
    }
}

initToken();