I'm implementing notification with signalr and pwa in mobile device. Everything works well while browser is open in mobile device. Also in server side I'm using asp.net mvc + Microsoft signalr. I can keep connection alive inside Browser with no problem (reconnect...) , but in PWA that's another story , since I can't use jQuery inside service worker (due to its nature there is no html DOM accessible).
Is there any way that I can keep signalr alive with pwa? like when browser gets closed or goes inactive for a while? also I'm trying to avoid GCM and FCM.(corporation policy)
Related
I am developing a mobile app using react native. My backend application is developed using springboot. My app talks to backend using REST.
I want to send some notification to the user of the app from my backend (via one of the options mentioned below). This cannot be a Push Notification as user can disable push notification for my app.
On recieveing this notification the app will communicate with backend using rest api's to fetch more details and complete the transaction.
I want to know what would be a better strategy to send a notification for the user.
Websockets
Using Firestore event listener(since I am already using Firebase to send Push Notitification for users who have enabled it)
SSE(server sent events)
Periodic polling from the app to backend (I do not like this approach)
I know this is a bit broad topic. I just need some pointers as to which option is better in terms of fault tolerance, performance and scalability.
I want to know how this is generally implemented. I am new to app development.
In my opinion Firebase is the best option for mobile apps, websocket can be be closed by android and are not always controllable. They also consume a lot of energy which can drain phone battery.
I have the same requirements for a project where need to send notification regardless of using a third party application like Firebase. How I achieve this I will share with you may be it will help you.
Backend -> ASP.NET Core
Real time communication -> SignalR Core
Protocols -> Websocket, Server sent events, Long Pooling
RN Package -> react-native-push-notification
It was completely fine except for one drawback that it will only communicate and send push notification when app is running (background/foreground) I think it depend on your situation and your requirement if your app is continuously will in the main app this will work for you otherwise you need to use the third-party service like Firebase and it will also work when your app is not running just need to be connected with the internet.
I am trying to implement background service in Xamarin. Forms which is kept running in the device until the app is installed on the device.
I want to send the user's current location to the server at every 5 seconds even if the app is in the stack or removed from the stack.
I need to send the user's location to the server using this service and keep the signalR connection alive in the background
A bound service is an exception to the rule introduced in Oreo. An app can still run in the background when your app is backgrounded. I didn't require any changes in my app when I first supported Oreo and Pie is the same. You should probably look at starting your bound service by creating your own Application class and starting your bound service in its OnCreate.
I am coding a vue.js app using web pushes with Firebase Cloud Messaging and I wondered if it was possible to send a web push to a user and in case the user was offline, to somehow store it for later display when the user opens the app again. Is there a principled approach to this problem, i.e. managing web pushes when the end user is offline?
The reason I am asking this is that, so far, all the web push notifications I've committed to FCM server with tokens of offline clients (i.e. desktop browsers) went into oblivion. To be sure, FCM didn't try pushing the notification again when the clients went back online.
For this reason I am considering coding a self-made dispatcher to manage web push for offline clients, but I need to make sure my efforts are worth it.
updated: I am now able to display notifications sent to an offline client after coming back online using appropriate time_to_live values. However, only the latest notification is displayed. How is there any specific reason why?
FCM's default behavior is exactly like that. From the docs:
If the device is not connected to FCM, the message is stored until a connection is established (again respecting the collapse key rules). When a connection is established, FCM delivers all pending messages to the device.
I am looking for a solution to fetch geolocation periodically (every 1 minute) on mobile browser. I did some research and came to know that fetching geolocation in background (when phone is locked or webapp not active) is impossible. In foreground it works ok.
I am making a web app where I fetch user location and send it to my server. All works ok, until the point where user locks his/her phone. I tried many things for workarounds:
setInterval to get geolocation, works fine in foreground but fails in background
converted my web app into Android using cordova, but same problem existed
used https://github.com/mauron85/cordova-plugin-background-geolocation this plugin for android
works good in both foreground and background
but the same plugin does not work in iPhone (I did not tested it, I searched in Google before moving ahead)
Its not good to release my app with just one platform (android) support, thus this workaround also failed for me.
I also considered using serviceworkers for my web app but it seems issue persist for background
https://github.com/w3c/ServiceWorker/issues/745
I have another solution in mind, but before investing time in it, I wish to know if someone has tried it already.
I learnt about Push notifications:
Web app client registers to Push notification
It sends
subscriber object to my server
My server using this object sends
message to Push notification server
Push notification server
sends messages to my web app client
My web app client wakes up my
service worker for a brief period to show the notification message
As per google documentation:
Note: In the current implementation
of Chrome, whenever we receive a push message and we don't have our
site visible in the browser we must display a notification. That is,
we can't do it silently without the user knowing. If we don't
display a notification the browser automatically creates one to let
the user know that the app is doing work in the background.
I won't mind showing a permanent notification to users until my app is running. I am ready for this trade-off.
Now, my question is, at step 5, when I wake up the service worker **is there a chance I call my main.js (main web app) which might be running in background **, will fetch the geolocation and update it to my server?
Has someone tried this solution already with success or failure, please inform.
Can you try Page visibility Api, which listens for visibilitychange of a browser tab is hidden or switched to other tab (in case of browser). For mobiles, it's just a try.
src : https://developer.mozilla.org/en-US/docs/Web/API/Page_Visibility_API
or You can look into this answer too..
Detecting when screen is locked
I want to create a chat application for ios, android and windows phones as well as it should work with browsers in the future. My search led me to using Signal R with Azure Mobile Services(AMS).
My questions:
1) SignalR uses Websockets under the hood. Is websocket supported in Android, IOS, windows phones and all mobile/desktop browsers??
2) If not, how will it effect using SignalR with AMS?
3) Or should I just use Push notifications supported in AMS?
4) Any sample app/code snippet you can share. Note that I will be using Xamarin for my app development.
5) Any advice you can give for same.
Azure Mobile Services has SignalR integrated, and Azure Mobile Services provide a SDK for client apps, I suppose it is provide out-of-the box
See
Real-time with ASP.NET SignalR and Azure Mobile .NET Backend
Master the Managed Azure Mobile Services Backend–Part Four
High value mobile backend capabilities included
You will find many capabilities included in Mobile Services and readily available for your Web API. Mobile push notifications, real-time notifications with SignalR (auto-scaled out), social auth for your consumer apps, offline data sync for occasionally connected scenarios, to name a few.
Samples:
https://github.com/gshackles/RealTimeGallery
Sample to help developers to implement Push Notification, through Azure Notification Hubs, in mobile applications.
Note:
Azure Mobile Service is based in WebAPI!
For that you want, you should not use only Push Notification because Push Notification in iOS could not be read by the application if the user ignore it, only in android or windows you can get and save it. Another thing that can be a problem is the fact if the app is running you should not show the push notification and you should show a pop up with the notification... and the push notification can have a delay from the Push Notification Service (Apple, GCM, WNS...). Push notification are a notification that something happened in the app when the user is not using it.
In my opinion you should use AMS+SignalR for realtime communication and then Push Notification for update the user then he not using the app.
Using SignalR is efficient to save yourself from hitting any push notification cap if you ant to limit your costs. But you'll need to either turn notifications on/off at the right time when the app becomes active or inactive, otherwise the app may go in the background and push notifications won't be sent.
You can use a pure push approach where notifications are shown when the app is inactive/in the background, and whenthe app is active, you simply intercept the notification in the app, consume it and cancel it so it doesn't get shown. I have written a blog post on this approach along with 3 samples in Github for iOS, Android and Windows Universal at http://www.ageofmobility.com/2014/10/06/azurechatr-building-a-cross-platform-chat-app-for-windows-ios-android/.