I have a viewpager in my activity. Inside the viewpager, there is a fragment and the fragment contains recyclerview. Once a notification is received, I want to add the new item in my recyclerview and want to highlight it as well.
Activity class:
protected void onNewIntent(Intent intent) {
super.onNewIntent(intent);
boolean not_id = intent.getBooleanExtra(AppConstants.NEW_NOTIFICATION, false);
String bid_id = intent.getStringExtra(AppConstants.BID_NOTIFICATION_ID);
if(not_id){
ActiveBidFragment frag = ActiveBidFragment.newInstance(bid_id, "");
frag.setBid_id(bid_id);
frag.newBidReceived();
frag.setBid_id("0");
Log.i(TAG,"~~~~done refreshing");
}
}
Fragment:
public void newBidReceived(){
fetchActiveBids();
}
private void fetchActiveBids(){
if(mActiveBidPresenter == null)
mActiveBidPresenter = new ActiveBidPresenterImpl(this);
mActiveBidPresenter.getActiveBids();
}
#Override
public void onFetchedActiceBidsSuccess() {
if(bids == null)
bids = new ArrayList<ActiveBid>();
bids.clear();
bids.addAll(AppContext.getInstance().getActiveBids());
adapter.notifyDataSetChanged();
}
Adapter class:
#Override
public void onBindViewHolder(final ViewHolder holder, final int position) {
Log.i(TAG, "~~~~on Bind Holder");
String bid_id = ((ActiveBidFragment) mListener).getCurrentBidId();
List<Bid> bids = mActiveBids.get(position).getBid();
The presenter class calls a method to show dialog,which is:
Presenter Class:
#Override
public void getActiveBids() {
mActiveBidView.showProgressBar(AppConstants.FETCHING_ACTIVE_BIDS);
String vendor_id = Preferences.getActiveInstance(null).getVendor_id();
mActiveBidInteractor.fetchActiveBids(vendor_id, this);
}
#Override
public void showProgressBar(String msg) {
if(mProgressBar != null && mProgressBar.isShowing())
mProgressBar.dismiss();
mProgressBar = CodeUtil.generateWaitingDialog(getActivity(), msg);
mProgressBar.show();
}
#Override
public void fetchedActiveBidSuccessfully(JSONObject response) {
try{
Gson gson = new Gson();
ActiveBidResponse resp = gson.fromJson(response.toString(), ActiveBidResponse.class);
String status = resp.getStatus();
if(status.equals(AppConstants.LOGIN_SUCCESS)){
List<ActiveBid> activeBids = resp.getData();
AppContext.getInstance().setActiveBids(activeBids);
//AppContext.getInstance().setFetchNewActiveBids(false);
mActiveBidView.onFetchedActiceBidsSuccess();
}else{
mActiveBidView.onFetchedActiveBidsFailed();
}
}catch (Exception ex){
mActiveBidView.onFetchedActiveBidsFailed();
}
finally {
mActiveBidView.hideProgressBar();
}
}
Interactor Class:
#Override
public void fetchActiveBids(String vendor_id, OnActiveBidFinished mListener) {
String url = AppConstants.ACTIVE_BID_URL;
Map<String,String> params = new HashMap<String, String>();
params.put(AppConstants.VENDOR_ID, vendor_id);
JsonObjectRequest loginRequest = new JsonObjectRequest(Request.Method.POST,
url,
new JSONObject(params),
createMyReqSuccessListener(mListener),
createMyReqErrorListener(mListener));
VolleySingleton.getRequestQueue().add(loginRequest);
}
Dialog Class:
public static ProgressDialog generateWaitingDialog(Context context, String message){
ProgressDialog progressDialog = new ProgressDialog(context, AlertDialog.THEME_HOLO_LIGHT);
progressDialog.setCancelable(false);
progressDialog.setMessage(message);
return progressDialog;
}
In dialog, I get error as a nullpointerexception, it shows getActivity as null.
Is there some other way I can achieve what I am trying to achieve, may be like recreating the whole instance of the activity if the activity already exists
Update:
Changed the fragment creation to this:
ActiveBidFragment frag = (ActiveBidFragment) adapter.getItem(0);
frag.setBid_id(bid_id);
frag.newBidReceived();
frag.setBid_id("0");
//adapter is the viewpagerpadapter to which fragment is attached
Your fragment will get the getActivity() always null, unless your fragment is attached with the activity.
In your case:
ActiveBidFragment frag = ActiveBidFragment.newInstance(bid_id, "");
frag.setBid_id(bid_id);
frag.newBidReceived();
frag is not attach with any activity.
I am maintaining the fragment instance in a hashmap inside my fragmentpageradapter and then I am referncing it in my onNewIntent. That's the only solution I could get. Its like a singleton pattern, till the activity is alive. If someone postes better solution, I would seriously like to know it
Related
My application makes a webservice call using volley, in order to update recyclerView every 10 seconds. Besides memory usage increase in 10 seconds constantly until it hits the max heap size. Then GC starts doing its job, but the memory usage does not come back down like at the beginning.
Using Eclipse MAT or Android Studio analyzer tasks, I could'nt find a single leak in my code.
I want to know that if there are suspects of leaking in my code. Any help will be appreciated.
Below I have 3 classes:
EventService send a message to MainActivity using sendBroadcast() in every 10 seconds.
MainActiviy will get message from EventService using BroadcastReceiver and calls update operation within its Fragment
EventListFragment, which is inside the MainActivity, contains a RecyclerView, that needs to be updated.
Here is my EventService:
public class EventService extends Service {
private volatile boolean isCanceled = false;
public static final String KEY_MESSAGE = "connection";
public EventService() {}
#Override
public int onStartCommand(final Intent intent, int flags, int startId) {
Runnable r = new Runnable() {
#Override
public void run() {
while (!isCanceled) {
try {
Intent i = new Intent("android.intent.action.MAIN");
AppController.getInstance().cancelPendingRequests("json_obj_req");
i.putExtra(KEY_MESSAGE, MESSAGE);
sendBroadcast(i);
Thread.sleep(10000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
};
Thread eventThread = new Thread(r);
eventThread.start();
return Service.START_STICKY;
}
#Override
public void onDestroy() {
isCanceled = true;
}
#Override
public IBinder onBind(Intent intent) {
return null;
}
}
Here is my MainActivity:
public class MainActivity extends AppCompatActivity {
private Intent intent;
private BroadcastReceiver mReceiver;
private EventListFragment eventListFragment;
private IntentFilter intentFilter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
private void setView() {
eventListFragment = (EventListFragment) getSupportFragmentManager().findFragmentById(R.id.frgEventList);
}
#Override
protected void onResume() {
intent = new Intent(this, EventService.class);
mReceiver = new MyReceiver(eventListFragment);
this.registerReceiver(mReceiver, intentFilter);
intent = new Intent(this, EventService.class);
startService(intent);
}
#Override
protected void onPause() {
super.onPause();
stopService(intent);
unregisterReceiver(mReceiver);
}
private static class MyReceiver extends BroadcastReceiver {
private WeakReference<EventListFragment> eventListFragment = null;
public MyReceiver(EventListFragment eventFragment) {
this.eventListFragment = new WeakReference<>(eventFragment);
}
#Override
public void onReceive(Context context, Intent intent) {
String mssg = intent.getStringExtra(KEY_MESSAGE);
EventListFragment eventFragment = eventListFragment.get();
if (mssg.equals(MESSAGE) && eventFragment != null) {
//Update recyclerView
eventFragment.eventToList();
}
}
}
}
And here is my EventListFragment:
public class EventListFragment extends Fragment {
private View view;
private RecyclerView recyclerView;
private LinearLayoutManager mLayoutManager;
private EventAdapter eventAdapter;
private RequestData requestData;
private ArrayList<EventModel> eventList;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
view = inflater.inflate(R.layout.fragment_event_list, container, false);
return view;
}
#Override
public void onResume() {
super.onResume();
setView();
setControl();
}
private void setView() {
recyclerView = (RecyclerView) view.findViewById(R.id.frg_recycler_view);
}
private void setControl() {
if (eventAdapter == null && mLayoutManager == null) {
eventList = new ArrayList<>();
eventAdapter = new EventAdapter(getActivity().getApplicationContext(), eventList);
mLayoutManager = new LinearLayoutManager(getActivity().getApplicationContext());
recyclerView.setLayoutManager(mLayoutManager);
recyclerView.setHasFixedSize(true);
recyclerView.addItemDecoration(new DividerItemDecoration(getActivity(), LinearLayoutManager.VERTICAL));
recyclerView.setAdapter(eventAdapter);
}
recyclerView.addOnItemTouchListener(new RecyclerItemListener(getActivity().getApplicationContext(), recyclerView, new RecyclerItemListener.RecyclerTouchListener() {
#Override
public void onClickItem(View v, int position) {
EventModel model = eventList.get(position);
SQLiteHandler db = SQLiteHandler.getInstance(getActivity().getApplicationContext());
//some instances
}
#Override
public void onLongClickItem(View v, int position) {
}
}));
}
//make service call
public void eventToList() {
if (requestData == null) {
requestData = new RequestData(getActivity());
}
final ArrayList<EventModel> newList = new ArrayList<>(); //are you leaking?
requestData.getEventToday(new RequestData.VolleyCallback() {
#Override
public void onSuccess(JSONObject result) {
for (int i = 0; i < result.length(); i++) {
try {
JSONObject item = result.getJSONObject(Integer.toString(i));
EventModel eventModel = new EventModel();
String title = item.getString("title");
String start = item.getString("start");
String end = item.getString("end");
String date = item.getString("date");
eventModel.setDate(date);
eventModel.setStartTime(start);
eventModel.setEndTime(end);
eventModel.setTitle(title);
newList.add(eventModel);
} catch (JSONException e) {
e.printStackTrace();
}
}
eventAdapter.update(newList);
}
});
}
}
Many thanks!
First of all, a design consideration: is it necessary to call web service every 10 seconds? Do you know when/how often server data changes?
Every time you read data from web server, application have to do a lot of work: you create many object, update the adapter etc. Moreover, think about network traffic, you use network every 10 seconds.
There are somethings you can do:
Increment wait time: in this way, you reduce the number of created object/per seconds.
Reduce local reference for temporary objects (see following code)
Check if recycler view's adapter, before add new values, the old ones was correctly deferred.
Evaluate if it is possible to use technology to push data, you to avoid data polling. You can see GCM.
For consideration #2, i try rewrite eventToList method:
public void eventToList() {
if (requestData == null) {
requestData = new RequestData(getActivity());
}
requestData.getEventToday(new RequestData.VolleyCallback() {
#Override
public void onSuccess(JSONObject result) {
ArrayList<EventModel> newList = new ArrayList<>();
JSONObject item;
EventModel eventModel;
String title;
String start;
String end;
String date;
for (int i = 0; i < result.length(); i++) {
try {
item = result.getJSONObject(Integer.toString(i));
eventModel = new EventModel();
title = item.getString("title");
start = item.getString("start");
end = item.getString("end");
date = item.getString("date");
eventModel.setDate(date);
eventModel.setStartTime(start);
eventModel.setEndTime(end);
eventModel.setTitle(title);
newList.add(eventModel);
} catch (JSONException e) {
e.printStackTrace();
}
}
eventAdapter.update(newList);
}
});
}
I am using Firebase for my apps back end and I am retrieving my data as excepted. After I retrieve my data, I am posting it by using otto bus and the code can be seen below.
#Subscribe
public void loadBrothers(ServiceCalls.SearchBrothersRequest request) {
final ServiceCalls.SearchBrothersResponse response = new ServiceCalls.SearchBrothersResponse();
response.Brothers = new ArrayList<>();
Firebase reference = new Firebase("my data's url here");
reference.addListenerForSingleValueEvent(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
int index = 0;
for (DataSnapshot brotherSnapchat : dataSnapshot.getChildren()) {
BrotherFireBase bro = brotherSnapchat.getValue(BrotherFireBase.class);
Log.i(LOG_TAG, bro.getName());
Log.i(LOG_TAG, bro.getWhy());
Log.i(LOG_TAG, bro.getPicture());
Log.i(LOG_TAG, bro.getMajor());
Log.i(LOG_TAG, bro.getCross());
Log.i(LOG_TAG, bro.getFact());
Brother brother = new Brother(
index,
bro.getName(),
bro.getWhy(),
bro.getPicture(),
bro.getMajor(),
bro.getCross(),
bro.getFact());
response.Brothers.add(brother);
index++;
}
bus.post(response);
}
#Override
public void onCancelled(FirebaseError firebaseError) {
}
});
Once the data is in my RecyclerView, I am to click an item and it's respective activity is to pop up in a custom activity dialog. However, since the activity is a dialog, you can see the RecyclerView reloading in the background. This does not happen when I do not retrieve the data from the internet. After a few clicks around, the app crashes due to an out of memory exception. Is there something I am missing?
Here is the activity where the recyclerView is found:
#Override
public View onCreateView(final LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_meet_a_brother, container, false);
adapter = new BrotherRecycleAdapter((BaseActivity) getActivity(),this);
brothers = adapter.getBrothers();
recyclerView =(RecyclerView) view.findViewById(R.id.fragment_meet_a_brother_recycleView);
recyclerView.setLayoutManager(new GridLayoutManager(getActivity(),3));
setUpAdapter();
bus.post(new ServiceCalls.SearchBrothersRequest("Hello"));
return view;
}
private void setUpAdapter(){
if(isAdded()){
recyclerView.setAdapter(adapter);
}
}
#Subscribe
public void onBrosLoaded(final ServiceCalls.SearchBrothersResponse response){
int oldBrotherLength = brothers.size();
brothers.clear();
adapter.notifyItemRangeRemoved(0, oldBrotherLength);
brothers.addAll(response.Brothers);
//Delete for Debug method...
adapter.notifyItemRangeChanged(0,brothers.size());
Log.i(LOG_TAG, Integer.toString(brothers.size()));
}
#Override
public void onBrotherClicked(Brother brother) {
Intent intent = BrotherPagerActivity.newIntent(getActivity(),brother);
Log.i(LOG_TAG,brother.getBrotherName() + " was Clicked");
startActivity(intent);
}
Just in case, here is also the activity that is started when a list item is clicked, it is a viewPager activity:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_brother_pager);
brothers = new ArrayList<>();
bus.post(new ServiceCalls.SearchBrothersRequest("Hello"));
FragmentManager fragmentManager = getSupportFragmentManager();
viewPager = (ViewPager) findViewById(R.id.activity_brother_viewPager);
viewPager.setAdapter(new FragmentStatePagerAdapter(fragmentManager) {
#Override
public Fragment getItem(int position) {
Brother brother = brothers.get(position);
return BrotherDetailsFragment.newInstance(brother);
}
#Override
public int getCount() {
return brothers.size();
}
});
}
#Subscribe
public void onBrosLoad(final ServiceCalls.SearchBrothersResponse response){
brothers.clear();
brothers.addAll(response.Brothers);
viewPager.getAdapter().notifyDataSetChanged();
Brother brother = getIntent().getParcelableExtra(BROTHER_EXTRA_INFO);
int brotherId = brother.getBrotherId();
for(int i=0;i<brothers.size();i++){
if(brothers.get(i).getBrotherId() == brotherId){
viewPager.setCurrentItem(i);
break;
}
}
Log.i(LOG_TAG, Integer.toString(brothers.size()));
}
public static Intent newIntent(Context context, Brother brother){
Intent intent = new Intent(context,BrotherPagerActivity.class);
intent.putExtra(BROTHER_EXTRA_INFO,brother);
return intent;
}
Any help is greatly appreciated thank you!
in public void onBrotherClicked(Brother brother) where RecyclerView resides, you call:
Intent intent = BrotherPagerActivity.newIntent(getActivity(),brother);
which will call
Intent intent = new Intent(context,BrotherPagerActivity.class);`
in newIntent of your viewPager activity.
This could be a recursive call.
try adding:
public static Intent newIntent(Context context, Brother brother){
Intent intent = new Intent(context,BrotherPagerActivity.class);
intent.putExtra(BROTHER_EXTRA_INFO,brother);
return intent;
}
in Activity where your RecyclerView resides. And call your ViewPage activity there.
-- UPDATE --
Call your viewpager activity (which is used to show Brother data) with the following code:
private void showBrotherData(Brother brother){
Intent intent = new Intent(this, BrotherPagerActivity.class);
intent.putExtra(BROTHER_EXTRA_INFO, brother);
this.startActivity(intent);
}
I found the answer! I changed my recyclerView to only updated if the size of the array was zero.
#Subscribe
public void onBrosLoaded(final ServiceCalls.SearchBrothersResponse response){
int oldBrotherLength = brothers.size();
Log.i(LOG_TAG, "Brother lists old size" + Integer.toString(oldBrotherLength));
if(oldBrotherLength ==0){
brothers.clear();
adapter.notifyItemRangeRemoved(0, oldBrotherLength);
brothers.addAll(response.Brothers);
//Delete for Debug method...
adapter.notifyItemRangeChanged(0,brothers.size());
} else{
return;
}
Log.i(LOG_TAG, Integer.toString(brothers.size()));
}
I don't know how good this solution is in terms of cleaness but it works for me. I hope this helps someone.
Hi there I'm thinking about what is the correct and best way to handle Activity, Fragment, AsyncTask and DialogFragments together.
My current state is that I start my Activity and replace its ContentView with my Fragment, in which I got an EditText and one Button.
Tapping my Button executes an AsyncTasks which Requests random things and takes some time. Meanwhile I display a DialogFragment begging for patience.
Desired behavior is that, e.g. I rotate my screen my DialogFragment keeps being displayed for the time my AsyncTask is running. After that I want to show up a simple toast displaying the information I got from my HttpRequest.
Compact overview about how I thought it would work:
BaseFragment keeps a WeakReference to the Activity it's attached to
AsyncTask keeps a WeakReference to Fragment which exectures it
AsyncTasks onPreExecute() shows up the DialogFragment
AsyncTasks onPostExecute() dissmisses the DialogFragment
BaseFragment holds DialogFragment
Unfortunately this is not the way it works, on orientation change my DialogFragment keeps being displayed and no toast is showing up.
What am I doing wrong ?
public class BaseFragment extends Fragment{
private static final String TAG = BaseFragment.class.getSimpleName();
protected WeakReference<AppCompatActivity> mActivity;
private TemplateDialogFragment dialogFragment;
public WeakReference<AppCompatActivity> getAppCompatActivity(){ return mActivity; }
#Override
public void onAttach(Context context) {
if(!(context instanceof AppCompatActivity)) {
throw new IllegalStateException(TAG + " is not attached to an AppCompatActivity.");
}
mActivity = new WeakReference<>((AppCompatActivity) context);
super.onAttach(context);
}
#Override
public void onDetach() {
mActivity = null;
super.onDetach();
}
#Override
public void onStart() {
super.onStart();
showContent();
}
public void showContent(){
}
public void showDialog(String title, String content){
dialogFragment = new TemplateDialogFragment();
Bundle bundle = new Bundle();
bundle.putString(TemplateDialogFragment.DIALOG_TITLE, title);
bundle.putString(TemplateDialogFragment.DIALOG_MESSAGE, content);
dialogFragment.setArguments(bundle);
dialogFragment.show(getFragmentManager(), TemplateDialogFragment.FRAGMENT_TAG);
}
public void notifyTaskFinished(String result) {
dismissDialog();
if(mActivity != null && !mActivity.get().isFinishing()) {
Toast.makeText(mActivity.get().getApplicationContext(), result, Toast.LENGTH_LONG).show();
}
}
private void dismissDialog(){
if(dialogFragment != null && dialogFragment.isAdded()) {
dialogFragment.dismissAllowingStateLoss();
}
}
}
...
public class TemplateFragment extends BaseFragment {
private static final String TAG = TemplateFragment.class.getSimpleName();
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
return inflater.inflate(R.layout.test_fragment, container, false);
}
#Override
public void showContent() {
super.showContent();
Button startTask = (Button) getAppCompatActivity().get().findViewById(R.id.button0);
final BaseFragment instance = this;
startTask.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
CustomAsyncTask task = new CustomAsyncTask(instance);
EditText input = (EditText) getAppCompatActivity().get().findViewById(R.id.text0);
task.execute(input.getText().toString());
}
});
}
private static class CustomAsyncTask extends AsyncTask<String, Void, String> {
WeakReference<BaseFragment> weakBaseFragmentReference;
private CustomAsyncTask(BaseFragment fragment) {
weakBaseFragmentReference = new WeakReference<>(fragment);
}
#Override
protected void onPreExecute() {
super.onPreExecute();
weakBaseFragmentReference.get().showDialog("Executing", "Working on the request...");
}
#Override
protected String doInBackground(String... params) {
HttpURLConnection con = HttpUrlConnectionFactory.createUrlConnection("https://www.httpbin.org/bytes/" + (params[0] == null ? "1" : params[0]));
return HttpRequester.doGet(con).getResponseAsString();
}
#Override
protected void onPostExecute(String response) {
super.onPostExecute(response);
if(weakBaseFragmentReference.get() == null) {
return;
}
weakBaseFragmentReference.get().notifyTaskFinished(response);
}
}
}
*Edit:
After some time researching this theme I'm sure a Service is the best solution for most of my field of use. Also I used AsyncTaskLoaders a lot, because there is a smooth control of lifecycle....
Use progress bar instead of DialogFragment.
AsyncTask should only be used for tasks that take quite few seconds.
AsyncTask doesn't respect Activity lifecycle, and can lead to memory leaks.
Check some gotchas.
You can try AsyncTaskLoader to survive configuration changes.
I am fetching data from json with Volley and populating RecyclerView with the parsed data but I ran into a bit of problem:
The call to get the items is in onCreate method, so the call is repeated each time the activity is recreated both from configuration changes and otherwise; hence the data is reloaded. So I found this answer that uses parcelables
and this article on Codepath (still on parcelables). After I have followed the instructions explicitly (or so I feel), there seems to be no change: the call to get data is repeated each time the activity is recreated.
FruitItems
public class FruitItems implements Parcelable {
private String fruit_title;
private String fruit_description;
private String fruit_image;
public String getFruit_title() {
return fruit_title;
}
public void setFruit_title(String fruit_title) {
this.fruit_title = fruit_title;
}
public String getFruit_description() {
return fruit_description;
}
public void setFruit_description(String fruit_description) {
this.fruit_description = fruit_description;
}
public String getFruit_image() {
return fruit_image;
}
public void setFruit_image(String fruit_image) {
this.fruit_image = fruit_image;
}
#Override
public int describeContents() {
return 0;
}
#Override
public void writeToParcel(Parcel dest, int flags) {
dest.writeString(this.fruit_title);
dest.writeString(this.fruit_description);
dest.writeString(this.fruit_image);
}
public FruitItems() {
}
protected FruitItems(Parcel in) {
this.fruit_title = in.readString();
this.fruit_description = in.readString();
this.fruit_image = in.readString();
}
public static final Parcelable.Creator<FruitItems> CREATOR = new Parcelable.Creator<FruitItems>() {
#Override
public FruitItems createFromParcel(Parcel source) {
return new FruitItems(source);
}
#Override
public FruitItems[] newArray(int size) {
return new FruitItems[size];
}
};
}
MainActivity
public class MainActivity extends AppCompatActivity {
private final String TAG = "MainActivity";
private final String KEY_POST_ITEMS = "fruititems";
//List of fruits
private List<FruitItems> mFruitItemsList;
//Views
private RecyclerView recyclerView;
private RecyclerView.Adapter adapter;
private ProgressDialog mProgressDialog;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Log.d(TAG, "onCreate called");
//Initializing Views
recyclerView = (RecyclerView) findViewById(R.id.fruit_recycler);
LinearLayoutManager layoutManager = new LinearLayoutManager(this);
recyclerView.setLayoutManager(layoutManager);
if (savedInstanceState != null && savedInstanceState.containsKey(KEY_POST_ITEMS)) {
mFruitItemsList = savedInstanceState.getParcelableArrayList(KEY_POST_ITEMS);
} else {
//Initializing the fruitlist
mFruitItemsList = new ArrayList<>();
if (NetworkCheck.isAvailableAndConnected(this)) {
getData();
} else {
final Context mContext;
mContext = this;
final AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(this);
alertDialogBuilder.setTitle(R.string.alert_titl);
alertDialogBuilder.setCancelable(false);
alertDialogBuilder.setIcon(R.mipmap.ic_launcher);
alertDialogBuilder.setMessage(R.string.alert_mess);
alertDialogBuilder.setPositiveButton(R.string.alert_retry, new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
if (!NetworkCheck.isAvailableAndConnected(mContext)) {
alertDialogBuilder.show();
} else {
getData();
}
}
});
alertDialogBuilder.setNegativeButton(R.string.alert_cancel, new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
finish();
}
});
alertDialogBuilder.show();
}
}
adapter = new FruitAdapter(mFruitItemsList, this);
recyclerView.setAdapter(adapter);
}
#Override
public void onSaveInstanceState(Bundle savedInstanceState) {
savedInstanceState.putParcelableArrayList(KEY_POST_ITEMS, ArrayList<? extends Parcelable>))mFruitItemsList);
super.onSaveInstanceState(savedInstanceState);
}
//Getting json data
private void getData(){
Log.d(TAG, "getData called");
//Show progress dialog
mProgressDialog = new ProgressDialog(MainActivity.this);
mProgressDialog.setCancelable(false);
mProgressDialog.setMessage(this.getResources().getString(R.string.load_fruit));
mProgressDialog.show();
//Creating a json request
JsonArrayRequest jsonArrayRequest = new JsonArrayRequest(ConfigFruit.GET_URL,
new Response.Listener<JSONArray>() {
#Override
public void onResponse(JSONArray response) {
Log.d(TAG, "onResponse called");
//Dismissing the progress dialog
if (mProgressDialog != null) {
mProgressDialog.hide();
}
//calling method to parse json array
parseData(response);
}
},
new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
}
});
//Creating request queue
RequestQueue requestQueue = Volley.newRequestQueue(this);
//Adding request to the queue
requestQueue.add(jsonArrayRequest);
}
//parsing json data
private void parseData(JSONArray array){
Log.d(TAG, "Parsing array");
for(int i = 0; i<array.length(); i++) {
FruitItems fruitItem = new FruitItems();
JSONObject jsonObject = null;
try {
jsonObject = array.getJSONObject(i);
fruitItem.setFruit_title(jsonObject.getString(ConfigFruit.TAG_POST_TITLE));
fruitItem.setFruit_description(jsonObject.getString(ConfigFruit.TAG_POST_DESCRIPTION));
//Parsing image
JSONObject fruitImage = jsonObject.getJSONObject("thumbnail");
fruitItem.setFruit_image(fruitImage.getString("url"));
} catch (JSONException w) {
w.printStackTrace()
}
mFruitItemsList.add(fruitItem);
}
adapter.notifyItemRangeChanged(0, adapter.getItemCount());
}
}
I may not be a pro but I know that I have goofed somewhere in the codes above, else it should have worked.
Now, my question is where did I goof and how do I plug this mistake?
EDIT
I have edited the codes above to reflect the answer that I accepted. It works fine but there is still a problem.
I start Activity B from MainActivity. If I press the back-button in Activity B the data is saved but when I press the up-button, the getData is called again and the data is re-fetched.
Please, is there anyway around this?
You don't seem to have an onSaveInstanceState in your mainactivity. You need something like
#Override
protected void onSaveInstanceState (Bundle outState) {
super.onSaveInstanceState(outState);
outState.putParcelableArrayList(KEY_POST_ITEMS,mFruitItemsList) ;
}
In order to retain your data for the activity that is about to be destructed and the one that is being created, you need to override the onSaveInstance callback
#Override
public void onSaveInstanceState(Bundle savedInstanceState) {
savedInstanceState.putParcelableArrayList(KEY_POST_ITEMS, (ArrayList)mFruitItemsList);
super.onSaveInstanceState(savedInstanceState);
}
NOTE: always remember to call the superclass.
I've looked in other threads, and they all show how to do this on creation of the fragment, not asynchronously.
I had 3 activities, each of these activities did an asynchronous okhttp3.HttpUrl get in order to receive data from a third party JSON API. Then when complete, it would populate the activity with data.
I have since converted these 3 activities to fragments and put them in a parent activity. However, this means every time I load the new parent activity, it does THREE okhttp3.HttpUrl fetches to populate the 3 fragments.
All three fetches go to the same URL, so I was thinking to instead put the okhttp3.HttpUrl request in the parent activity and once its done, send the entire JSON package down to the fragments. This is after creation of the fragments... so I have no idea how to do this...
Any ideas?
My Parent Activity:
public class ChallongeEvent extends AppCompatActivity {
private TextView tab_text;
private String EVENT_ID, URL;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_challonge_event);
init();
}
private void init() {
tab_text = (TextView) findViewById(R.id.tab_text);
Intent intent = getIntent();
EVENT_ID = intent.getStringExtra("event_id");
if (Challonge.SUBDOMAIN.isEmpty()) {
URL = "https://api.challonge.com/v1/tournaments/" + EVENT_ID + ".json";
} else {
URL = "https://api.challonge.com/v1/tournaments/" + Challonge.SUBDOMAIN + "-" + EVENT_ID + ".json";
}
String titles[] = new String[] { getString(R.string.players), getString(R.string.matches) };
int numTabs = intent.getIntExtra("num_tabs", 1);
EventAdapter adapter = new EventAdapter(getSupportFragmentManager(), titles, numTabs);
ViewPager pager = (ViewPager) findViewById(R.id.pager);
pager.setAdapter(adapter);
pager.setCurrentItem(intent.getIntExtra("num_tabs", 1) - 1);
SlidingTabLayout sliding_tabs = (SlidingTabLayout) findViewById(R.id.sliding_tabs);
sliding_tabs.setDistributeEvenly(true);
sliding_tabs.setViewPager(pager);
}
private void populate() {
AsyncGet fetch = new AsyncGet(new AsyncResponse() {
#Override
public void processFinish(String output) {
}
});
HttpUrl.Builder urlBuilder = HttpUrl.parse(URL).newBuilder();
urlBuilder.addQueryParameter("api_key", Challonge.API_KEY);
urlBuilder.addQueryParameter("include_participants", "1");
urlBuilder.addQueryParameter("include_matches", "1");
fetch.execute(urlBuilder.build().toString());
}
public void setTabText(String text) {
tab_text.setText(text);
}
}
class EventAdapter extends FragmentPagerAdapter {
private final String[] titles;
private final int numTabs;
public EventAdapter(FragmentManager fm, String mTitles[], int mNumTabs) {
super(fm);
this.titles = mTitles;
this.numTabs = mNumTabs;
}
#Override
public Fragment getItem(int position) {
switch (position)
{
case 1:
return new ChallongeMatches();
default:
return new ChallongePlayers();
}
}
#Override
public String getPageTitle(int position) {
return titles[position];
}
#Override
public int getCount() {
return numTabs;
}
}
Please try this code
Bundle bundle = new Bundle();
bundle.putString("key", "value");
// to send object use below code
// bundle.putSerializable("key", object);
Fragment fragment = new Fragment();
fragment.setArguments(bundle);
getSupportFragmentManager().beginTransaction().replace(R.id.container, fragment).commit();
to get value use below code
String value= getIntent().getExtras().getString("value");
or
Object object = getIntent().getExtras().getSerializable("value");
You can also use a LocalBroadcastManager to send the data to all three fragments. Here's a tutorial on how to use this as well. The nice thing about this is that you can send the data, even if no one is listening, and easily add another receiver without having to change anything from the sender.
Solved it myself... in my AsyncFetch call I put:
AsyncGet fetch = new AsyncGet(new AsyncResponse() {
#Override
public void processFinish(String output) {
for (Fragment fragment : getSupportFragmentManager().getFragments())
{
if (fragment instanceof ChallongePlayers) {
((ChallongePlayers) fragment).parsePlayers(output);
} else if (fragment instanceof ChallongeMatches) {
((ChallongeMatches) fragment).parseMatches(output);
}
}
}
});
This parses through all the possible fragments in the activity and sends the data to specific actions.
make a method in each fragments :
public void setData(Bundle bundle){
//set you data to a local variable,
//and set it to the views on creation,
//OR
//call this method on Post execute of your async task
}
then in the main activity:
YourFragment fragment = new YourFragment;
fragment.setData(bundle);
getSupportFragmentManager().replace(R.id.frame, fragment).commit;
OR
call the fragment.setData(bundle) on the onPostExecute() of your async task