I m doing an interview homework that s an android app the on

Question

I m doing an interview homework that s an android app the only thing that s left to do is network error handling I have no idea how to approach this could you help

Bruno_ · Answer

i ve tried implementing BroadcastReceiver but it wouldn t work

Bruno_ · Answer

this piece of code is working but I d have to setup a loop that would check the connection I don t think that s the best idea ```val cm = getSystemService Context CONNECTIVITY SERVICE as ConnectivityManager val activeNetwork NetworkInfo = cm activeNetworkInfo val isConnected Boolean = activeNetwork isConnectedOrConnecting false```

Brian · Answer

you can monitor for changes in connectivity using `ConnectivityManager NetworkCallback`

satyan · Answer

Read ConnectivityManager documentation you should find something useful to handle the offline case To handle network errors upon requests you should read your HTTP client documentation Retrofit on top of OKHttp Java HTTP This Slack is supposed to be about Kotlin so it might not be the best place to ask interview homework questions Try doing the Sunshine app application course on Udacity there must be a part about network calls

Bruno_ · Answer

thanks that ll solve the problem

Bruno_ · Answer

or it won t I have to support API14 would it be a good idea to listen for a flowable error somewhere

Bruno_ · Answer

not sure if it s a good idea tho I ve separated my retrofit module and I return flowable from it the only place that has the flowable is a repository

Bruno_ · Answer

this one works

Ryan Mentley · Answer

as it happens I was semi recently helping update one of the training articles on exactly this topic <https developer android com training monitoring device state connectivity status type>

Ryan Mentley · Answer

note specifically the bit about ConnectivityManagerCompat

Anastasia Finogenova · Answer

You can always go for a retey button on a snackbar or a dialog or even come up with a new UI for the network error state with the retry option it is very straightforward imo

Anastasia Finogenova · Answer

The network error will be returned differently depending on the network library you use You mentioned you use Flowable so apparently RxJava your network error is gonna fall in the the onError callback So inside the onError callback check if the error is instance of Sockettimeoutexception or unknownhostexception if using retrofit and then just show your network error prompt with the retry

Bruno_ · Answer

the only place that has access to the flowable is the repository which means that I can do `doOnError` only there would it be a bad idea to throw an error in a repository and catch it in a fragment using a global exception handler <https stackoverflow com questions 4427515 using global exception handling on android>

Bruno_ · Answer

other solution would be to somehow use rxjava flowable instead of a view model so fragment would call repository directly instead of fragment gt view model gt repository flow is that a good idea

Bruno_ · Answer

I should probably mention that I use MVVM

Bruno_ · Answer

< Anastasia Finogenova> < Ryan Mentley>

Bruno_ · Answer

it s more of an architecture question I know how to handle the rror display a snackbar etc I just don t know how to design the module properly

Bruno_ · Answer

I think I ll do something like that <https stackoverflow com questions 50855715 android mvvm how to handle network request failiures>

Raul Tunduc · Answer

< Bruno > you can check this too

Anastasia Finogenova · Answer

Just return this Flowable from the repo method and subscribe to it in the view model and do actions on result on success or on error

Anastasia Finogenova · Answer

Throwing an error in the repo and catching in the fragment is a very bad not straightforward idea

Raul Tunduc · Answer

From my point of view I would NOT recommend using RX for HTTP requests It s easier with Coroutines

Anastasia Finogenova · Answer

It is not easier imo after using coroutines a lot I realized they are not easier in any way that RxJava from the dev stand point

Anastasia Finogenova · Answer

I am recommending Flowable as he said he already has it

Mikael Alfredsson · Answer

Since its an interview assignment shouldn t be able to solve it if youre qualified for the position troll The error you should get back when you are trying to call the endpoint so a normal try catch works for that and for the download automatically retry I would go for the first option and use Workmanager to achieve that

Bruno_ · Answer

< Mikael Alfredsson> it was my first real android app smile I m a fullstack dev on a daily basis anyway what I did was pretty much what you can see in the last SOF link I ve sent throwable field in a view model that I check on every view model update