https://forum.ionicframework.com/t/push-notifications-with-ionic-2/63851/4
https://github.com/fechanique/cordova-plugin-fcm
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https://www.youtube.com/watch?v=7yXtzhqT1uk
https://medium.com/@ankushaggarwal/push-notifications-in-ionic-2-658461108c59#.ff6hz41ot
.sender_id who is sender or This guy is send message.
.FCM_token (api_key) it's right to use FMC, who get token, then can send
.Device token this device (which device)
Where is come from?
.sender_id 、 FCM_token from FCM (firebase)
.Device_token from device
How to get?
.sender_id 、 FCM_token : login firebase console -> settings -> colud messageing
.Device_token : If ionic2, when you use
Push @ionic/cloud-angular push.register().then(t: PushToken)
this time get Push Token. see video 7:54
So how to work? (If see youtube video, I guess)
.FCM_token: Who take token, who can send message. FCM get FCM_token, then send message to send_id under all register.
.sender_id: App or reciver must have this info, when message come from FCM into Phone, then check send_id is correct or not.
.Device_token:
A、Device must send(register) phone's Device_toke to FCM sender_id, then register info(device_token) under send_id. If not register, send_id can't know any devices.
B、Sometime send message to only one device, must use FCM_token + Device_token then only send to one device.
(This Video 9:38 bottom have "Device Options")
(https://github.com/aggarwalankush/push-notification-server
AndroidPush.java see code have "YOUR_DEVICE_TOKEN" )
https://medium.com/@ankushaggarwal/push-notifications-in-ionic-2-658461108c59#.ff6hz41ot
https://devdactic.com/ionic-push-notifications-guide/