Develop Reference

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

Android - Implementing a means to get 'real' time in offline apps

Background
The company I work for is creating an app that collects information from various device events and sensor data.
One of the things we would like to be able to do is use time to process the data when it gets to the server.
We would also like there to be an acceptable amount of "offline time" allowed, i.e., the app could be used for its purpose even while offline until the next server data update is required etc.
Problem
One issue is that the user can just change the device time.
We overlooked this, and have been able to successfully generate events for the previous day, which would mean that our app could be fooled in situations where device time is a factor, which is very uncomfortable.
Imagined solutions
Obviously I can ensure that the app is always sync'd to the server before it starts collecting important data, and then use server time and make all further time relative to that.
Another way might be to keep a reference to something like the last update time or even the app install time and work out time relative to that.
Questions
How do people get around this typically?
Are there any libraries out there that can be used to enforce real device time?
Thanks guys

Time since the app is open in android

Hello
In my android application i would like to get Time since when the app is opened.
Initially what i tried was getting the time when the app is loaded from the server and then taking the difference with the current time from the device.But by doing that if the user changes the time then i willnot be getting the actual time.
Its not posiible to hit the server again for the same.
Is there any way to achieve this in android?
Please share your valuable suggestions.
Thanks in advance:)

Try the "SystemClock" class, "uptimeMillis()" method.
Store the result in a variable when the app starts.

Echoing what I said for your other question, you first need to become familiar with the activity lifecycle and understand the novel meanings (almost meaninglessness) of common words like "open" and "start" in the life of an android app.
There isn't any way you can prevent the user from changing the system time - you just don't have the right to do that to users. Normally this should be a rare event, unless you do something that makes them want to, such as lock them out of a free version of your app after so many minutes. (However if the phone is on a mobile network, presumably the mobile network occasionally adjusts its time to correct for errors in the device's oscillator, or administrative time changes)
What you can do is check the system time on every entry point to your application. If it ever goes backwards, well... something is going on. If the clock has been set back, you could assume no time between the calls with the negative time difference and resume your time meter from there, at least keeping all the previous used time in your record.
It may be that there are cpu cycle counters which you could query and correlate to system time, but this may be highly device specific and may in fact be resettable. And it may get weird if the cpu frequency is demand throttled.
You might be able to set a countdown timer as a bound on the maximum possible time between entry points at which you could meter. I don't know if these work reliably across system time changes or not - ideally they would. Testing or reading the source will reveal.

Use elapsedRealtime in your onCreate() store it. More reliable.