I have to pass the recycler view item I get from my database to another fragment.
public class FragLoad extends Fragment {
EditText g_type;
EditText l_capacity, date, quotation;
Button search;
RecyclerView recyclerView;
List<RPostLoad> rPostLoads;
SupportPlaceAutocompleteFragment source,destination;
private static final String URL_RecyclerLoad="http://192.168.43.38/internship_project/android_web_services/RecyclerLoad.php";
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.frag_load, container, false);
g_type=view.findViewById(R.id.goodstype);
l_capacity=view.findViewById(R.id.loadCap);
date=view.findViewById(R.id.txtDate);
quotation=view.findViewById(R.id.txtQuotations);
search=view.findViewById(R.id.postSearch);
recyclerView=view.findViewById(R.id.rvload);
recyclerView.setLayoutManager(new LinearLayoutManager(this.getActivity()));
recyclerView.setHasFixedSize(true);
rPostLoads=new ArrayList<>();
source= (SupportPlaceAutocompleteFragment) getChildFragmentManager().findFragmentById(R.id.place_autocomplete_fragment2);
destination= (SupportPlaceAutocompleteFragment) getChildFragmentManager().findFragmentById(R.id.place_autocomplete_fragment1);
search.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
rvLoad();
}
});
return view;
}
private void rvLoad() {
Map<String, String> params = new HashMap<>();
params.put("g_type", g_type.getText().toString());
AndroidNetworking.post("http://192.168.43.38/internship_project/android_web_services/RecyclerLoad.php").addBodyParameter(params).setTag("Login").setPriority(Priority.LOW).build().getAsJSONObject(new JSONObjectRequestListener() {
#Override
public void onResponse(JSONObject response) {
try {
Log.d("TAG", "Response" + response.toString());
JSONArray array=response.getJSONArray("Data");
for (int i=0;i<array.length();i++){
JSONObject product=array.getJSONObject(i);
rPostLoads.add(new RPostLoad(
product.getString("owner_name"),
product.getString("g_type"),
product.getString("truck_cap")
));
}
RPostLoadAdp adp=new RPostLoadAdp(getActivity(),rPostLoads);
recyclerView.setAdapter(adp);
} catch (JSONException e) {
e.printStackTrace();
}
}
#Override
public void onError(ANError anError) {
Toast.makeText(getActivity(), "Server time out please try later", Toast.LENGTH_SHORT).show();
}
});
}
}
Above code is of the class from where I get the recycler item from database and need to send the recycler view item to another fragment. The thing is that I am a beginner at android so I have no idea how to send it. The fragment in which I have to receive the recycler item is empty so i didnt post it here.
you have one Activity one Fragment and one RecyclerView
and yor Activity opens Fragment and inside of fragment you implemented the RecylcerView
to communicate between your Activity and RecyclerView you need to have a Listener
create this Interface (listener) :
public interface OnSomeThingHappens {
public void onEvent(); // you can use some argument for the method
}
then in your Activity implement the interface and create a method to your fragment to pass the listener from activity to the fragment and then pass it from fragment to RecyclerView's adapter. your activity will be some thing like this :
public class ActivityMain extends AppCompatActivity implements OnSomeThingHappens{
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
YourFragment yourFragment = (YourFragment) getFragmentManager().findFragmentById(R.id.test_fragment);
yourFragment.setOnSomeThingListener(this); // this indication the listener that is implemented in ActivityMain
}
#Override
public void onEvent() {
// to do your logic
}
}
and in your Fragment when you implement RPostLoadAdp send the listener object adapter to the adapter using a setter method in adapter.
then you will have access to the listener and when you want you can call the onEvent() method of listener and in ActivityMain the method will be called.
now you can do your logic in this method in ActivityMain (send some data to other fragment or ..)
hope this help.
Related
First of all, I have 2 fragments and they show different json values(2 links). If I change fragment(.replace()), that fragment get values with retrofit and show it. It works well but other fragment is deleted with values. After change fragment, it downloads again so I change structure. I want to take 2 json objects once so I get json objects in mainactivity and fragments get these with methods. They work well in first opening but if i open a fragment second time, it gives this error. How can I solve it?
java.lang.IllegalStateException: Already executed.
at retrofit2.OkHttpCall.enqueue(OkHttpCall.java:84)
Code is very long, i will show main structure.
MainActivity.java
public class MainActivity extends AppCompatActivity
{
private Call<Restaurant[]> restaurantCall;
private Call<Dining[]> diningCall;
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//Restaurant Json value
RestaurantInterface restaurantInterface = RetroClient.getClient().create(RestaurantInterface.class);
restaurantCall = restaurantInterface.getJsonValues();
//Dininghall Json value
DiningInterface diningInterface = RetroClient.getClient().create(DiningInterface.class);
diningCall = diningInterface.getJsonValues();
}
public Call<Restaurant[]> RestaurantJson()
{
return this.restaurantCall;
}
public Call<Dining[]> DiningJson()
{
return this.diningCall;
}
}
RestaurantFragment.java (Other fragment has same structure)
public class RestFragment extends Fragment
{
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
View view = inflater.inflate(R.layout.fragment_rest, container, false);
Call<Restaurant[]> call = ((MainActivity) getActivity()).RestaurantJson();
call.enqueue(new Callback<Restaurant[]>()
{
.
.
Summing up, in order to avoid the "Already executed" exception, clone the call:
public Call<Restaurant[]> RestaurantJson()
{
return this.restaurantCall.clone();
}
public Call<Dining[]> DiningJson()
{
return this.diningCall.clone();
}
If you want to execute the call in the activity and not in the fragment as you are actually doing, then you need to call enqueue(new Callbak(... in your activity.
So you need something like this:
public class RestFragment extends Fragment {
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_rest, container, false);
((MainActivity) getActivity()).RestaurantJson(this);
}
public void onResponse(Response<T> response) {
//your fragment code on response
}
...
}
public class MainActivity extends AppCompatActivity {
public void RestaurantJson(final RestFragment fragment)
{
RestaurantInterface restaurantInterface = RetroClient.getClient().create(RestaurantInterface.class);
restaurantCall = restaurantInterface.getJsonValues();
restaurantCall.enqueue(new Callback<Restaurant[]>() {
#Override
public void onResponse(Call<T> call, Response<T> response) {
...
fragment.onResponse(response);
}
}
...
}
The same for your DiningFragment and your dining call...
I have an Activity with three tabs and three Fragments. First Fragment shows the list of song titles and the second tab displays the selected song. The details of the songs is coming from a database.
I am implementing SearchView feature so that whatever search text user enters, only those songs should be displayed in the index.
This is exactly like the way phone book work in our devices.
I'm not able to understand how to refresh the first Fragment when the search query changes.
I'm basically looking for the method that I can call to refresh the first Fragment.
Got my answer here Android refresh a fragment list from its parent activity as suggested by #Prem. Works perfectly fine for me.
Its is achievable by making an interface
MainActivity.java
public class MainActivity extends Activity {
public FragmentRefreshListener getFragmentRefreshListener() {
return fragmentRefreshListener;
}
public void setFragmentRefreshListener(FragmentRefreshListener fragmentRefreshListener) {
this.fragmentRefreshListener = fragmentRefreshListener;
}
private FragmentRefreshListener fragmentRefreshListener;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button b = (Button)findViewById(R.id.btnRefreshFragment);
b.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
if(getFragmentRefreshListener()!=null){
getFragmentRefreshListener().onRefresh();
}
}
});
}
public interface FragmentRefreshListener{
void onRefresh();
}}
MyFragment.java
public class MyFragment extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View v = null; // some view
/// Your Code
((MainActivity)getActivity()).setFragmentRefreshListener(new MainActivity.FragmentRefreshListener() {
#Override
public void onRefresh() {
// Refresh Your Fragment
}
});
return v;
}}
Below is the one way, you can easily do it. You just have to save the fragment instance. That's all.
private class ViewPagerAdapter extends FragmentStatePagerAdapter {
private SparseArray<Fragment> array = new SparseArray<>();
ViewPagerAdapter(FragmentManager manager) {
super(manager);
}
#Override
public Fragment getItem(int position) {
array.setValueAt(position, myFragment);
return myFragment;
}
#Override
public int getCount() {
return 3;
}
public SparseArray<Fragment> getFragmentArray() {
return array;
}
}
Then from your activity, you can get all viewpager fragment easily from adapter instance.
MyFragment fragment = (MyFragment) adapter.getFragmentArray().get(0); // get first fragment and casting it to your origin fragment
Then create a method on that fragment. Call like below:
fragment.myFragmentMethod(String myData){}
Have a nice day!
I have this issue of sending some data back and forth between a fragment and its container activity, I succeeded in doing it. What puzzles me is sending my data from the fragment to the activity, at first I implemented OnResume(), OnStop() and sent the data through an intent and that created an infinite loop so I removed them. Then I did setRetainInstance(true) and it worked and gave me the wanted behavior.
My Question is How my data are really being sent and where in the fragment lifecycle ?
The Right approach is to use Interfaces. Don't use onStop or setRetainInstance()
See this. It will solve you problem.
Pass data from fragment to actvity
You can also achieve this by using Interface, using an EventBus like LocalBroadcastManager, or starting a new Activity with an Intent and some form of flag passed into its extras Bundle or something else.
Here is an example about using Interface:
1. Add function sendDataToActivity() into the interface (EventListener).
//EventListener.java
public interface EventListener {
public void sendDataToActivity(String data);
}
2. Implement this functions in your MainActivity.
// MainActivity.java
public class MainActivity extends AppCompatActivity implements EventListener {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
#Override
public void sendDataToActivity(String data) {
Log.i("MainActivity", "sendDataToActivity: " + data);
}
}
3. Create the listener in MyFragment and attach it to the Activity.
4. Finally, call function using listener.sendDataToActivity("Hello World!").
// MyFragment.java
public class MyFragment extends Fragment {
private EventListener listener;
#Override
public void onAttach(Activity activity)
{
super.onAttach(activity);
if(activity instanceof EventListener) {
listener = (EventListener)activity;
} else {
// Throw an error!
}
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_my, container, false);
// Send data
listener.sendDataToActivity("Hello World!");
return view;
}
#Override
public void onDetach() {
super.onDetach();
listener = null;
}
}
Hope this will help~
I have this interface in my activity.
public interface LogoutUser {
void logout();
}
My fragment implements this interface, so in my fragment, I have this:
#Override
public void logout() {
// logout
}
In my activity I call
mLogoutUser.logout();
Where mLogoutUser is of the type LogoutUser interface.
My issue is the mLogoutUser object that is null. How can initialize it?
Thank you!
As I said in my comment, I resolved this issue using onAttach method in my fragment, but in this way you have to have the callback field (mLogoutUser in this case) declared in the fragment, and initialize it this way:
public class MyFragment extends ListFragment {
LogoutUser mLogoutUser;
// Container Activity must implement this interface
public interface LogoutUser {
public void logout();
}
#Override
public void onAttach(Context context) {
super.onAttach(context);
// This makes sure that the container activity has implemented
// the callback interface. If not, it throws an exception
try {
mLogoutUser = (LogoutUser) context;
} catch (ClassCastException e) {
throw new ClassCastException(context.toString()
+ " must implement LogoutUser");
}
}
...
}
More info in Communicating with Other Fragments.
But if your case is the field declared in the activity, you can use the onAttachFragment method from your activity to initialize your listener field this way:
#Override
public void onAttachFragment(Fragment fragment) {
super.onAttachFragment(fragment);
mLogoutUser = (LogoutUser) fragment;
}
Also, you can use an event bus to make this communication between fragments and activities. An option is the Otto library, from Square.
Sample for creating callback from Fragment to Activity
public interface CallBackListener {
void onCallBack();// pass any parameter in your onCallBack which you want to return
}
CallBackFragment.class
public class CallBackFragment extends Fragment {
private CallBackListener callBackListener;
public CallBackFragment() {
// Required empty public constructor
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_call_back, container, false);
}
#Override
public void onActivityCreated(#Nullable Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
//getActivity() is fully created in onActivityCreated and instanceOf differentiate it between different Activities
if (getActivity() instanceof CallBackListener)
callBackListener = (CallBackListener) getActivity();
}
#Override
public void onViewCreated(View view, #Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
Button btn = (Button) view.findViewById(R.id.btn_click);
btn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if(callBackListener != null)
callBackListener.onCallBack();
}
});
}
}
CallbackHandlingActivity.class
public class CallbackHandlingActivity extends AppCompatActivity implements CallBackListener
{
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_all_user);
}
#Override
public void onCallBack() {
Toast.makeText(mContext,"onCallback Called",Toast.LENGTH_LONG).show();
}
}
Android Fragments - Communicating with Activity
You need to get a reference to your fragment with getFragmentById() or getFragmentByTag()
getFragmentManager().findFragmentById(R.id.example_fragment);
You can use kotlinx Channel to send data or callback between fragments and activity or vice versa
In your Mainactivity:
val loginPromptChannel = Channel<LoginPromptState>()
val loginStateFlow = loginPromptChannel.receiveAsFlow()
//onCreate
lifecycleScope.launchWhenStarted {
loginStateFlow.collect() { state ->
when (state) {
is LoginPromptState.Login -> {
//smooth scroll to login fragment
binding.viewpager.setCurrentItem(2, true)
}
}
}
}
//create sealed a class
sealed class LoginPromptState {
object Login : LoginPromptState()
}
In your fragment send callback like:
lifecycleScope.launch {
val channelLogin = (activity as MainActivity).loginPromptChannel
channelLogin.send(MainActivity.LoginPromptState.Login)
}
I have this interface in my activity.
public interface LogoutUser {
void logout();
}
My fragment implements this interface, so in my fragment, I have this:
#Override
public void logout() {
// logout
}
In my activity I call
mLogoutUser.logout();
Where mLogoutUser is of the type LogoutUser interface.
My issue is the mLogoutUser object that is null. How can initialize it?
Thank you!
As I said in my comment, I resolved this issue using onAttach method in my fragment, but in this way you have to have the callback field (mLogoutUser in this case) declared in the fragment, and initialize it this way:
public class MyFragment extends ListFragment {
LogoutUser mLogoutUser;
// Container Activity must implement this interface
public interface LogoutUser {
public void logout();
}
#Override
public void onAttach(Context context) {
super.onAttach(context);
// This makes sure that the container activity has implemented
// the callback interface. If not, it throws an exception
try {
mLogoutUser = (LogoutUser) context;
} catch (ClassCastException e) {
throw new ClassCastException(context.toString()
+ " must implement LogoutUser");
}
}
...
}
More info in Communicating with Other Fragments.
But if your case is the field declared in the activity, you can use the onAttachFragment method from your activity to initialize your listener field this way:
#Override
public void onAttachFragment(Fragment fragment) {
super.onAttachFragment(fragment);
mLogoutUser = (LogoutUser) fragment;
}
Also, you can use an event bus to make this communication between fragments and activities. An option is the Otto library, from Square.
Sample for creating callback from Fragment to Activity
public interface CallBackListener {
void onCallBack();// pass any parameter in your onCallBack which you want to return
}
CallBackFragment.class
public class CallBackFragment extends Fragment {
private CallBackListener callBackListener;
public CallBackFragment() {
// Required empty public constructor
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_call_back, container, false);
}
#Override
public void onActivityCreated(#Nullable Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
//getActivity() is fully created in onActivityCreated and instanceOf differentiate it between different Activities
if (getActivity() instanceof CallBackListener)
callBackListener = (CallBackListener) getActivity();
}
#Override
public void onViewCreated(View view, #Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
Button btn = (Button) view.findViewById(R.id.btn_click);
btn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if(callBackListener != null)
callBackListener.onCallBack();
}
});
}
}
CallbackHandlingActivity.class
public class CallbackHandlingActivity extends AppCompatActivity implements CallBackListener
{
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_all_user);
}
#Override
public void onCallBack() {
Toast.makeText(mContext,"onCallback Called",Toast.LENGTH_LONG).show();
}
}
Android Fragments - Communicating with Activity
You need to get a reference to your fragment with getFragmentById() or getFragmentByTag()
getFragmentManager().findFragmentById(R.id.example_fragment);
You can use kotlinx Channel to send data or callback between fragments and activity or vice versa
In your Mainactivity:
val loginPromptChannel = Channel<LoginPromptState>()
val loginStateFlow = loginPromptChannel.receiveAsFlow()
//onCreate
lifecycleScope.launchWhenStarted {
loginStateFlow.collect() { state ->
when (state) {
is LoginPromptState.Login -> {
//smooth scroll to login fragment
binding.viewpager.setCurrentItem(2, true)
}
}
}
}
//create sealed a class
sealed class LoginPromptState {
object Login : LoginPromptState()
}
In your fragment send callback like:
lifecycleScope.launch {
val channelLogin = (activity as MainActivity).loginPromptChannel
channelLogin.send(MainActivity.LoginPromptState.Login)
}