Gist 4 - Android Example

Ad.kt

data class Ad(val id: String)

SearchAdsApi.kt

object SearchAdsApi {

    fun searchAds(search: String): Observable<List<Ad>> {
        return Observable.just(listOf(Ad("1"), Ad("2")))
    }
}

SearchAdsFragment.kt

class SearchAdsFragment : Fragment(R.layout.fragment_search_ads), SearchAdsPresenter.SearchAdsView,
    TextWatcher {

    private val presenter = SearchAdsPresenter(this)

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)

        searchAdsEditText.addTextChangedListener(this)
    }

    override fun onTextChanged(s: CharSequence, start: Int, before: Int, count: Int) {
        presenter.onSearchChanges(s.toString())
    }

    override fun afterTextChanged(s: Editable?) {
        // nothing
    }

    override fun beforeTextChanged(s: CharSequence?, start: Int, count: Int, after: Int) {
        // nothing
    }

    override fun setProgressVisibility(visible: Int) {
        searchAdsProgressBar.visibility = visible
    }

    override fun showAds(ads: List<Ad>) {
        searchAdsResultTextView.text = ads.toString()
    }
}

SearchAdsPresenter.kt

class SearchAdsPresenter(private val view: SearchAdsView) {

    private val api = SearchAdsApi

    private val search: BehaviorSubject<String> = BehaviorSubject.create()

    init {
        search
            .subscribeOn(AndroidSchedulers.mainThread())
            .doOnNext { view.setProgressVisibility(View.VISIBLE) }
            .flatMap { searchAds(it) }
            .subscribe {
                view.setProgressVisibility(View.GONE)
                view.showAds(it)
            }
    }

    fun onSearchChanges(text: String) {
        search.onNext(text)
    }

    private fun searchAds(search: String): Observable<List<Ad>> {
        return api.searchAds(search)
            .subscribeOn(Schedulers.io())
            .doOnError { view.setProgressVisibility(View.GONE) }
    }

    interface SearchAdsView {
        fun setProgressVisibility(visible: Int)
        fun showAds(ads: List<Ad>)
    }
}