Data queries handleResponse called twice

General
1

I am calling Backendless.Data.of and it calls the callback twice with different data sets,resulting in inconsistent behaviour.Code:Log.i(TAG, “queryGiftCards() starting”);BackendlessDataManager.getInstance().queryGiftCards(new AsyncCallback<BackendlessCollection<Map>>() {

@Override
public void handleResponse(BackendlessCollection&lt;Map&gt; response) {

    Log.i(TAG, "queryGiftCards() handleResponse");

…public void queryGiftCards(AsyncCallback<BackendlessCollection<Map>> callback) {

Log.i(TAG, "queryGiftCards()");
QueryOptions queryOptions = new QueryOptions();
BackendlessDataQuery dataQuery = new BackendlessDataQuery(GiftCardsManager.COL_ENABLED + " = true");
queryOptions.addSortByOption(GiftCardsManager.COL_PROVIDER_ORDER + " ASC");
queryOptions.addSortByOption(GiftCardsManager.COL_CARD_ORDER + " ASC");
dataQuery.setQueryOptions(queryOptions);
dataQuery.setPageSize(Consts.BACKENDLESS_QUERIES_PAGE_SIZE);
Backendless.Data.of(Consts.TABLE_GIFT_CARDS).find(dataQuery, callback);

}Log:04-23 14:46:05.615 5514-5514/com.tapextreme.freegiftcards.rewards I/DataInitializer: queryGiftCards() starting
04-23 14:46:13.974 5514-5514/com.tapextreme.freegiftcards.rewards I/DataInitializer: queryGiftCards() handleResponse
04-23 14:46:14.725 5514-5514/com.tapextreme.freegiftcards.rewards I/DataInitializer: queryGiftCards() handleResponse
Also the data returns 13 rows in the first callback and then showing totalObjects=13 but dataSize=0 the second(see print screen)

2

attached print screen

response.png

3

What does BackendlessDataManager.getInstance() look like?

4

a simple singletone:

private static BackendlessDataManager mInstance = null;

private void BackendlessDataManager(){}

public static BackendlessDataManager getInstance() {

if (mInstance == null) {
    mInstance = new BackendlessDataManager();
}

return mInstance;

}

5

The only way a callback can be invoked twice is when the API is invoked twice. Have you confirmed with debugger or by studying the log that the API call happens only once?

6

Yes. it is clear from the code and the log:

public void queryGiftCards() {

Log.i(TAG, "queryGiftCards() starting");

BackendlessDataManager.getInstance().queryGiftCards(new AsyncCallback&lt;BackendlessCollection&lt;Map&gt;>() {

    private boolean firstResponse = true;

    @Override
    public void handleResponse(BackendlessCollection&lt;Map&gt; response) {

            Log.i(TAG, "queryGiftCards() handleResponse");
        GiftCardsManager giftCardsManager = GiftCardsManager.getInstance();

        if (firstResponse) {
            Log.i(TAG, "Total giftCards - " + response.getTotalObjects());
            firstResponse = false;
            giftCardsManager.clearGiftCards();
        }

        int size = response.getCurrentPage().size();

        if (size > 0) {
            List&lt;Map&gt; retData = response.getData();
            for (Map currGiftCardMap : retData) {

                GiftCard currGiftCard = new GiftCard(
                        (String) currGiftCardMap.get(GiftCardsManager.COL_PROVIDER),
                        (int) currGiftCardMap.get(GiftCardsManager.COL_DOLLAR_VALUE),
                        (int) currGiftCardMap.get(GiftCardsManager.COL_DISCOUNT_PERCNTAGE),
                        (int) currGiftCardMap.get(GiftCardsManager.COL_COIN_PRICE),
                        (int) currGiftCardMap.get(GiftCardsManager.COL_COIN_PRICE_AFTER_DISCOUNT),
                        (int) currGiftCardMap.get(GiftCardsManager.COL_PROVIDER_ORDER),
                        (int) currGiftCardMap.get(GiftCardsManager.COL_CARD_ORDER),
                        (String) currGiftCardMap.get(GiftCardsManager.COL_SPREAD),
                        (String) currGiftCardMap.get(GiftCardsManager.COL_ICON_URL),
                        (boolean) currGiftCardMap.get(GiftCardsManager.COL_ENABLED)
                );

                giftCardsManager.addGiftCard(currGiftCard);

/*
if (!giftCardsManager.isGiftCardIconExists(currGiftCard.getIconUrl())) {
fetchGiftCardProviderIcon(currGiftCard.getIconUrl());
}
*/
}
response.nextPage(this);
} else {

            //adNetworksManager.setIsInitialized(true);
            mOperationsStatus.put(OP_QUERY_GIFT_CARDS, true);
            notifyIfInitFinished();
        }
        Log.i(TAG, "queryGiftCards() Response handled");

    }

    @Override
    public void handleFault(BackendlessFault fault) {

        Log.e(TAG, "Error while loading giftCards: " + fault.getMessage());
        mOperationsStatus.put(OP_QUERY_GIFT_CARDS, true);
        notifyIfInitFinished();
    }
});

}from BackendlessDataManager:public void queryGiftCards(AsyncCallback<BackendlessCollection<Map>> callback) {

Log.i(TAG, "queryGiftCards()");
QueryOptions queryOptions = new QueryOptions();
BackendlessDataQuery dataQuery = new BackendlessDataQuery(GiftCardsManager.COL_ENABLED + " = true");
queryOptions.addSortByOption(GiftCardsManager.COL_PROVIDER_ORDER + " ASC");
queryOptions.addSortByOption(GiftCardsManager.COL_CARD_ORDER + " ASC");
dataQuery.setQueryOptions(queryOptions);
dataQuery.setPageSize(Consts.BACKENDLESS_QUERIES_PAGE_SIZE);
Backendless.Data.of(Consts.TABLE_GIFT_CARDS).find(dataQuery, callback);

}
Log:04-24 17:19:26.118 15274-15274/com.tapextreme.freegiftcards.rewards I/DataInitializer: queryGiftCards() starting
04-24 17:19:26.118 15274-15274/com.tapextreme.freegiftcards.rewards I/BackendlessDataManager: queryGiftCards()
04-24 17:19:27.788 15274-15274/com.tapextreme.freegiftcards.rewards I/DataInitializer: queryGiftCards() handleResponse
04-24 17:19:27.788 15274-15274/com.tapextreme.freegiftcards.rewards I/DataInitializer: queryGiftCards() Response handled
04-24 17:19:29.188 15274-15274/com.tapextreme.freegiftcards.rewards I/DataInitializer: queryGiftCards() handleResponse
04-24 17:19:29.188 15274-15274/com.tapextreme.freegiftcards.rewards I/DataInitializer: queryGiftCards() Response handled

This issue results in inconsistent behavior in viewing the data

Thanks,
Tal

7

Your second API call is here:

response.nextPage(this);

8

You are right.

The problem ended up being in android UI.
Thank you for your support, Mark