Hello everyone, I've posted a question on stackove...

# rx

[Hawazine Haouat]

Hello everyone, I've posted a question on stackoverflow around Flowable, Rx, Kotlin, Retrofit2. Thanks to take a look if you can 👍 https://stackoverflow.com/questions/45441074/multiple-retrofit2-requests-using-flowable-in-kotlin

[kioba]

this is how i would solve it:

Flowable.zip<User, Comments, Pair<User, Comments>>(
      postService.getUser(postId),
      postService.getCommentsByPostId(postId),
      BiFunction { user, comments -> Pair(user, comments) })
      .subscribeOn(<http://Schedulers.io|Schedulers.io>())
      .observeOn(AndroidSchedulers.mainThread())
      .bindToLifecycle(this)
      .map { (first, second) -> Triple(first, second, ExtraDatas()) }
      .subscribe({
        Log.d("MainActivity", "OnNext")
      }, {
        Log.d("MainActivity", "OnError")
      }, {
        Log.d("MainActivity", "OnComplete")
      })

Use the zip or zipWith functions to achieve your goal if the retrofit2 calls dont depent on each other. You can find out more here:
http://reactivex.io/documentation/operators/zip.html

after that map the data from the server with the mainActivity data together. Thats easy as well

and finally Kotlin has a very beautiful syntax for labdas so i would encourage you to use them with the specific subscribe function:
http://reactivex.io/RxJava/javadoc/io/reactivex/Flowable.html#subscribe(io.reactivex.functions.Consumer,%20io.reactivex.functions.Consumer,%20io.reactivex.functions.Action)

[kioba]

Also very important to note that i did not use only the raw Rxjava2 lib. i used the libs below:
RxAndroid <https://github.com/ReactiveX/RxAndroid>
for observeOn(AndroidSchedulers.mainThread()) to get the mainThread. This is because i saw your example and you manipulated the UI without specifing the thread you subscribed on. With this you can achieve that your subscription will be handled on the mainThread
RxLifecycle <https://github.com/trello/RxLifecycle>
for .bindToLifecycle(this) this will make sure you dont leave memoryleak if the activity is closed but your retrofit2 call did not finished

[Hawazine Haouat]

A big thank you @kioba for your help 🙏

[Hawazine Haouat]

Hope that one day I'll be able to do this by myself 😭 😄

[Hawazine Haouat]

So I've used what you've suggest to me and I've modify it a little bit, look:

[Hawazine Haouat]

Flowable.zip<User, List<Comment>, Pair<User, List<Comment>>>(
        postService.getUser(post.id),
        postService.getCommentsByPostId(post.id),
        BiFunction { user, comments -> Pair(user, comments) })
        .subscribeOn(<http://Schedulers.io|Schedulers.io>())
        .observeOn(AndroidSchedulers.mainThread())
        .map { (first, second) -> Pair(first, second) }
        .subscribe({
            Log.d("MainActivity", "OnNext")
            userTextView.text = it.first.name
            title.text = post.title
            body.text = post.body
            number_comments.text = it.second.size.toString()

        }, {
            Log.d("MainActivity", "OnError")
        }, {
            Log.d("MainActivity", "OnComplete")
        })

[Hawazine Haouat]

arf I've tried to reformat the code but it didn't worked ok anyway 😅

[Hawazine Haouat]

so instead of using Comment I've used List<Comment>

[Hawazine Haouat]

in order to have the number of comments by doing it.second.size.toString() I don't know if it's very elegant..

[Hawazine Haouat]

I've used the `Pair`instead of triple because I didn't understand what ExtraDatas() could do. Maybe I should find/calculate the number of comments inside this method 🤔

[kioba]

ExtraData was the “post” variable 🙂 just to combine it with the stream

[kioba]

but thats fine with your solutions as well! btw its very cool that you changed to List its much better that way! 🙂

[Hawazine Haouat]

✌️ thanks 😄

[Hawazine Haouat]

all the thanks to you as well, you save me many hours 👍

[Hawazine Haouat]

I've noticed something weird:

[Hawazine Haouat]

so when u click on the detail activity since this process is done asynchronously the data by default are displayed first and boum the correct data from the network are then displayed. Have you notice that when u use rx?

[kioba]

use progressbar in your Activity layout. When the activity starts, just start the progresbar, and hide your view (userTextView, number_comments, title, body)
After that add a line into the stream:

...
.doAfterTerminate { 
 prgoressbar.gone()
userTextView.visible()
...
 }
...

[kioba]

doAfterTerminate will execute after the observable finished with Complete or Error.

[Hawazine Haouat]

yeah this is what usually do with callback I hide/ display the progressbar. Cool thanks👍

[Hawazine Haouat]

Could you add the solution that you've previously suggested to the stackoverflow question? like this I will valid it. If u don't have time I'll add it no worries 😉

[Hawazine Haouat]

I've noticed that sometimes my first rx "request" that look for posts didn't go to onComplete, sometimes and it remains blocked on onNext. I've add what you've suggested previously .observeOn(AndroidSchedulers.mainThread()) and boum no more pb..👍

[kioba]

good idea! i will answare your stackowerflow as well. 🙂 thanks for the suggestion.
about the mainThread, threading is tricky sometimes, but i had no idea this will solve the problem, but now its clear as well 👍