Replace Async Task from RxAndroid

Question

I am new in rxAndroid, I just to simple replace asynTask from rxAndroid. I just want to create a list using db query in background

new AsyncTask<Void, Void, Void>() {
        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            startSppiner();
        }

        @Override
        protected Void doInBackground(Void... params) {
        List<masterDataTable> list = ServatiumApplication.daoSession.getMasterDataTableDao().queryBuilder().where(masterDataTableDao.Properties.MasterType.eq(ParserString.MD_SERVICE_LEVEL), masterDataTableDao.Properties.DeleteFlag.eq(SHOW_FLAG)).orderAsc(masterDataTableDao.Properties.Description).list();
        if (list.size() > 0) {
        PopUpValues values1 = new PopUpValues();
        values1.setValue(ParserString.SELECT_VALUE);
        values1.setName(ParserString.SELECT);
        serviceLevelList.add(values1);

        for (masterDataTable item : list) {
            PopUpValues values = new PopUpValues();
            values.setValue(item.getLookupCode());
            values.setName(item.getDescription());
            serviceLevelList.add(values);
        }

    }
            return null;
        }

        @Override
        protected void onPostExecute(Void aVoid) {
            stopSppiner();

        }
    }.execute();

Thanks for help in advance!!

https://stackoverflow.com/questions/31592399/convert-asynctask-to-rxandroid?rq=1 — taug, Jul 14 '17 at 12:31
I just want to inflate a list nothing can you share some code relate to it — Sundeep Badhotiya, Jul 14 '17 at 12:51

score 0 · Answer 1 · answered Jul 19 '17 at 04:38

This will do.

public void query(){
    startSppiner();
    Observable.fromCallable(new Func0<List<PopUpValues>>() {
        @Override
        public List<PopUpValues> call() {
            List<masterDataTable> list = ServatiumApplication.daoSession.getMasterDataTableDao().queryBuilder().where(masterDataTableDao.Properties.MasterType.eq(ParserString.MD_SERVICE_LEVEL), masterDataTableDao.Properties.DeleteFlag.eq(SHOW_FLAG)).orderAsc(masterDataTableDao.Properties.Description).list();
            List<PopUpValues> serviceLevelList = new ArrayList<PopUpValues>();
            if (list.size() > 0) {
                PopUpValues values1 = new PopUpValues();
                values1.setValue(ParserString.SELECT_VALUE);
                values1.setName(ParserString.SELECT);
                serviceLevelList.add(values1);

                for (masterDataTable item : list) {
                    PopUpValues values = new PopUpValues();
                    values.setValue(item.getLookupCode());
                    values.setName(item.getDescription());
                    serviceLevelList.add(values);
                }

            }
            return serviceLevelList;
        }
    })
    .subscribeOn(Schedulers.io())
    .observeOn(AndroidSchedulers.mainThread())
    .subscribe(new Subscriber<List<PopUpValues>>() {
        @Override
        public void onCompleted() {
            stopSppiner();
        }

        @Override
        public void onError(Throwable e) {

        }

        @Override
        public void onNext(List<PopUpValues> popUpValues) {
            // Here you get the serviceLevelList data
        }
    });
}

thanks for answer can we use same Observable to fetch multiple list from DB.If yes then how. — Sundeep Badhotiya, Aug 02 '17 at 13:19
Depends, what would be the model of multiple lists, if same then yes, all can be combined into one. — Ritt, Aug 02 '17 at 13:22

score 0 · Answer 2 · answered Nov 05 '18 at 03:30

below is the code I tried converting to Rx using the AsyncTask code provided above. You might need minor modifications, however, overall flow remains same.

Observable
    .fromIterable(
        ServatiumApplication.daoSession
            .getMasterDataTableDao()
            .queryBuilder()
            .where(
               masterDataTableDao
                  .Properties
                  .MasterType
                  .eq(ParserString.MD_SERVICE_LEVEL),
               masterDataTableDao.Properties.DeleteFlag.eq(SHOW_FLAG)
            )
            .orderAsc(masterDataTableDao.Properties.Description)
            .list()
    )
    //Get item one by one from the above list, create a PopupValues object and add to it
    .map(
        listItem -> {
            PopUpValues values = new PopUpValues();
            values.setValue(listItem.getLookupCode());
            values.setName(listItem.getDescription());
            return values;
        }
    )
    //Convert to List<PopupValues> list. toList() returns Single<List<PopupValues>>
    .toList()
    //When subscribe is called show spinner
    .doOnSubscribe(disposable -> startSppiner())
    //When job is done successfully or fails stop spinner
    .doOnSuccess(listOfPopupValues -> stopSppiner())
    .doOnError(throwable -> stopSpinner())
    //Do the job in io() thread
    .subscribeOn(Schedulers.io())
    //Give the resulting list to mainthread
    .observeOn(AndroidSchedulers.mainThread())
    .subscribe(
        result -> "get the List<PopUpValues>",
        error -> new Throwable("")
    );

Replace Async Task from RxAndroid

2 Answers2