I'm working on creating a coupon/deals app. The premise is that each day there will be special deals at different stores. When a user happens to be close to a store (within a geofence), I'd like to send a notification to the user of the coupon/deals at that store.
Given that the stores may change daily, I'm trying to figure out the best way to update the Geofences.
One idea - use AlarmManager to create an alarm that would trigger at like 12 am each day that sends an intent that starts a service that queries my server > pulls the list of new Geofences > sets those new Geofences.
Is that reasonable? Is there a better way to handle it?
Thanks!
You're on the right path, check CommonWare's Repository
It doesn't keep the device on wake up and only to do the service call.
Related
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
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 :)
Lately I am developing some new features of the app. My app is about displaying different events that are happening in a specific time and in a specific place.
Now I want for the user to be able to save a event like his favorite, which means that he potentially wants to attend that particular event. When a user mark an event as a favorite one, the time of the event and other details like place, name, description will be store on the device. Now the part that I am having some difficulties is the notification part.
What I want to do is that when the time is 1 hour before the beginning of the event a notification must be triggered in order to tell the user that the event will start in an hour. If I will say its an analogy with the agenda notifications.
Now the problem is to the right way of implementing it. I know how to use Notification in Android and also I know how to use background services . I have followed a lot of tutorials like : http://www.tutorialspoint.com/android/android_services.html, but I don't know which is the right way of implementing it.
One way is to store the data in a database, and run a background service to check periodically if the time of the phone is the right to trigger a notification for an event.But this would say that the service would run indefinitely in the background.
I also thought about using some store procedures in the database that check the values that are store over there and when the time comes, it triggers the service that triggers the notification.
I don't know if I am following the right way and I need to clarify these before I proceed.
Is there any tutorial to help me or any other idea that helps me achieve the same thing.
One way is to store the data in a database, and run a background service to check periodically if the time of the phone is the right to trigger a notification for an event.But this would say that the service would run indefinitely in the background.
This is rather wasteful. Is is the programming equivalent of the children in the back seat of the car chanting "are we there yet? are we there yet?".
I also thought about using some store procedures in the database that check the values that are store over there and when the time comes, it triggers the service that triggers the notification.
This is not supported in Android.
or any other idea that helps me achieve the same thing
Use AlarmManager to tell Android to give you control one hour before your event. The PendingIntent that you use with AlarmManager can trigger a BroadcastReceiver in your app that can raise the Notification.
I am building an app that shows user's friends' real-time locations on a map.
Each user updates his currnet location on the server (Parse.com) every defined interval (time and distance).
When a user opens the FindFriends activity, he'll get a map with markers on friends locations.
The friends locations data can be retrieved in two methods:
When activity is running, I am calling an AsyncTask that will download locations data from the server in a while loop (inside doInBackground), and after each time I call publishProgress() to handle the changes on the map.
I wrote a cloud code that is called every time a user updates his location on the server, which sends push notification to the relevant users (the user cant see the notification). When the FindFriends activity is running, a broadcast reciever is getting those pushes and update locations data on the map.
My question is: Which method is better for my needs or maybe I should do it differently? Of course I would like to keep battery consumption to minimum but not at expense of getting almost real time data.
I don't really think that this is an appropriate question, since you really should just make a prototype using each implementation, and see which is more performant in your particular use case. However, I can say that I definitely prefer the cloud solution. I've used GCM to implement a messaging client, and from my testing the updates are definitely really quick (very little noticeable lag time, when testing two clients side by side). So, I don't think that implementing it with GCM would negatively impact your user experience, and it does have the plus side of eliminating pointless server polling when, potentially, no updates could be present - which saves on battery.
If you want real time data then push notification GCM is not a good idea because, there is no guarantee that all users will get push notification in time. Sometime you will encounter delays in push notification.
Under given circumstances AsyncTask or Service can be a good way to perform required task, if they are handled properly. You should have control on AsyncTask/Service so that you can stop it any time you want.
I am designing an Android application that needs to receive constantly changing information (so the update interval must be very small).
Right now I am reading this information by consuming a REST WebService, but I am wondering if this is the best approach, regarding the battery drainage. This application would have to refresh the data being shown very often (specifically GPS data read from another system).
I have been reading about Google Cloud Messaging but I didn't find any comparisons between the two approaches.. Theoretically both approaches fit my needs since the data changes so frequently that it doesn't really matter whether it is updated by request or on a timer..
So my question is: Should I stick with WebServices or shift to GCM? Is there another battery-efficient solution?
Thanks in advance!
GCM utilises a connection that is already there - using this over your current polling methods is definitely recommended and will be much friendlier with the battery.
Think about it, in your case GCM will send you a notification to let you know you need to refresh data so instead of just calling refresh you have: receive the notification, process it and then call refresh. So if you need to refresh so often, like just say each minute and it's constant just skip the notification.
I would set a recurring alarm, get the intent in a BroadcastReceiver and trigger an IntentService for the refresh