Best way to Check remote database after fix time interval - android

I want to develop this simple instant messenger application. Now i can send text to database. Now i want to show a notification to the user if he receives a new message.For that i think i want to check the remote database after fix time i.e every 20 sec. What is the best way of doing that??
I know my question could end up being lame and this might not be the best technique to show user notification of new message but for now i just know that so i am implementing it . .
Suggestions are always welcome . .

Use a timer in a service, so it can occur even if the app is not in the foreground. As an aside, I wouldn't do it every 20s- far too often, if you got a significant user base it would cost you a lot of bandwidth. Back it off to less frequent- every 60 seconds is probably sufficient.

Related

How to auto-save a form on Android - Best practices

I am trying to introduce auto-save functionality on one of my Android applications. The idea is that as the user inputs first name, last name and after a fixed interval I would like to save that information to the server before the user hits Next button. The final goal is to have something similar to the draft option in the Gmail app where your email information is automatically saved. So, if there is a timer that runs every 10 seconds, I will pass the information on the screen to the ViewModel and let it deal with the logic of saving the data to the server.
A couple of options I have explored are.
Execute recurring code with a specified interval using Handler.
PeriodicWorkRequest -- however this option has a minimum interval of 15 minutes which is a little too much for my use case.
AlarmManager -- This option runs even if your application is not currently running, In my opinion, this option can be an overkill.
I wanted to know if there are best practices/blogs around this and if anyone I on the wrong path or potential red flags with this approach.
you can make countdown for 10 second, when countdown is down save the data and call the countdown again.
when your activity is destroyed, so stop the countdown

Is it good practice to fetch current time from internet?

I am making a mobile application and I need to have the current time. However, I don't want to depend on the user's phone time since it can be changed to whatever they want. Is it a good practice to fetch from a server its local time every minute or similar interval?
P.S: The app will use the time to show if a shop is open or closed so I don't mind about different timezones, I only need the time in the server's timezone.
Depending on the need of the application. If your application would require a connection from the internet, then yes. You can also put that in case there is an issue catching the online time, you can just take the user's time.
From personal experience I never had issues that the user would want to change their phone time, but there have been a few exception.
To use server times is fine. But based on that making decisions on data (shop open/not) is not a good practice. Whenever you make an api call, get the status if its closed or not. This will avoid user side data issues
If you want to show this information on a single shop page, fetch the time difference between current time and closing time from the server. This will help you to maintain the status on app side. this should not be for a very long time. You can use this solution if the difference is less than 10 or 15 mins.

How to make your app do something even when you're not doing anything or even using it

This question is vague but I am not sure what to Google for exactly.
But in my app I have a section where you create a list of tasks with various attributes, and a lot of these numbers are summed up and displayed in daily totals visually. But these daily totals should reset every 24 hours (based on the hour of the day the user chooses for the cutoff, e.g. 3 am if someone works late).
Right now: my database can hold all the data by day. Then my daily counters will visually display the numbers by pulling the corresponding data from the database looking for the current day. That's the easy part.
The hard part: I can refresh the counter after the time cutoff if the user rotates the screen or restarts the app because then it'll be looking for items in the database with a new day that won't be found, so everything will be 0 as intended. But what if the user is just staring at the screen as the time cutoff rolls by? How do I make the app refresh the counters once the time hits? What if they're not even using the app at all (either it's minimized in the background or not even active).
Do I need to have some kind of always-running loop in the background that checks the current time against the values in the database? If so, isn't this inefficient if it's always needing to pull values from a database based on time? What's the correct practice for something like this?
You can setup a service and schedule that service to run periodically so that it does whatever job you want it to do
maybe this article can help you.
Alarm manager and services will be ideal for you to implement to do something for your requirement.
Services : It will be running all the time irrespective of your life-cycle of activity.
Alarm manager: Inside services use alarm manager to trigger event to update UI at regular interval.
Finally you can use Local braodcast reciever to update your Activity from services.
You can check implemetation in details below :
Android update activity UI from service

Data exchange between Activities, Asynctasks and Services

Regarding the problematic stated below I have come to a point where I need to make a decision on whether to:
Start a Service once that has an AlarmManager inside which then starts the query every 10 minutes. This Service will only be stopped if the user sets an "Onn-Off" Switch to "Off".
Use an AlarmManager to start an IntentService every 10 Minutes. This Service will then only be started when needed and closed afterwards
Which of these ways is better when it comes to:
- Ability to exchange data received by the Service (Or Intenservice) with other activities/services
- Battery usage
- Overall "good coding habits" ?
Thanks!
Original Question:
I am a pretty new Android Developer and have come across a situation that I do not know how to solve. I have already spent several days searching for a solution but could not find one.
While trying to develop my first app idea I have started playing around with receiving and parsing data from the internet. What I have achieved so far is generating a query that receives JSON data via an API and parses this JSON. All of which is done inside an AsyncTask. The received data is then shown on the screen.
However, for the purpose of my app idea, I need this to be done in the background. What I have thought of is:
Starting a Service that pretty much has the same logic as my Asynctask. Managed by an AlarmManager, this service then requests, receives and parses the data in a specific time interval.
Now the tricky part begins:
The data that I receive (let's say every 10 minutes) shall be used to change an alarm clock. So, as a simple example, let's say the user can set his alarm clock to 08:00 in the morning. The application then checks the current temperature every 10 minutes and changes the alarm clock time to 07:45 if the temperature is below 0° celcius because the user has to wake up earlier to clear the ice off his car.
Also, when "waking up" the application, the current (or rather the latest received) tempereture shall be shown in the UI.
What would be the best way to achieve this? I am having some issues regarding passing/receiving data from AsyncTasks/Services to/from Activities.
My first approach would be to start a single service from the MainActivity, passing some data to the Service (like the initial time the alarm shall start and the current location of the user). The Service then has two seperate AlarmManagers. One of which is set to perform the actual alarm (waking up the user in the morning) and the other manages the time interval of getting the data from the internet.
My questions:
- Does my train of thought make any sense at all so far?
- What is the best way to pass and receive data to/from a service? My best guess would be to use intents to pass and a broadcastreceiver to receive data from the service. would this make sense in this specific situation?
I fear that it is not welcomed to post questions without putting in any effort of your own before. Although I did not add any actual source code, I hope you can see that I have dealt with these questions for quite a while now but could not really start coding before I know the structure of the application.
Thanks in advance
Use AlarmManager to start an IntentService as often as necessary (in your example, it should be sufficient to start checking the temperature about two hours before the user plans to get up and maybe again after one hour and finally half an hour before the normal wakeup time. More often only in case of extreme weather conditions.
It's not necessary to check the temperature exactly at 03:33 a.m. so use
setInexactRepeating(), this will be easier on the battery.
See also Scheduling Repeating Alarms
Write the results to SharedPreferences and have one IntentService check 15 minutes before normal wakeup time if the user should get up right then. Cancel the normal wakeup alarm in this case. Communicating via SharedPreferences (think of a mailbox) and local (!) Broadcasts is a good idea - cheap and secure :)

Service with AsyncTask performing a request every X time

I want to be reassured that I'm doing this the best practice way :
I have a list which order is changing on the server, therefore, I want every 20-30 sec. to perform a request to see if there were any changes in the order. So, I've created a Service which is bound to the Activity with the ListView, and the service every 20-30 sec. performs a request with an AsyncTask.
I chose to perform it with a Service because I want the list to be updated constantly, even when the application is in the background, And the AsyncTask is because I don't want it to be performed on the main thread.
Is this the right way to do it?
Thank you in advance,
Dan.
It will work, but your app will do a lot of unnecessary work. This will affect battery life. Besides that, according to documentation, if you use device radio, it stays full-powered at least for 20 seconds, which is also no good for battery. You have the following options:
Use Google Cloud Messaging. It will allow you to perform update only when this is really necessary.
If you don't want or cannot use GCM, follow this guide to optimize network access. Start with increasing the update interval (to 4 minutes at least).

Categories

Resources