Hi I've a tabbed activity, and in the first tab I fetch data from server and show it in a recyclerview within card views. For fetching the data from server I use the volley library. I want to implement the Pull to refresh to load the data (so whenever I pull it has to do the request to the network). And I want also to disable the network request whenever I switch between tabs (because when I change tab focus in my app it starts to fetching data) I want to do the network request only 1 time (when user log in first time) and then others requests maneged only by pull to refresh.
Here's my fragment where I've recyclerview and show the data:
public class Tab1History extends Fragment
{
private RecyclerView recyclerView;
private CespiteAdapter adapter;
UserSessionManager session;
private static final String URL_DATA = "http://mydata.php";
private List<CespiteOgg> cespiteOggList;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState)
{
View rootView = inflater.inflate(R.layout.tab1history, container, false);
recyclerView = (RecyclerView) rootView.findViewById(R.id.my_recycler_view);
recyclerView.setHasFixedSize(true);//every item of the RecyclerView has a fix size
recyclerView.setLayoutManager(new LinearLayoutManager(getContext()));
cespiteOggList = new ArrayList<>();
loadRecyclerViewData();
return rootView;
}
private void loadRecyclerViewData()
{
// Session class instance
session = new UserSessionManager(getActivity());
//get user data from session
HashMap<String, String> user = session.getUserDetails();
//get name
String name = user.get(UserSessionManager.KEY_NAME);
// get username
final String usernameUtente = user.get(UserSessionManager.KEY_USERNAME);
final ProgressDialog progressDialog = new ProgressDialog(getActivity());
progressDialog.setMessage("Carimento dati...");
progressDialog.show();
StringRequest stringRequest = new StringRequest(Request.Method.POST,
URL_DATA,
new Response.Listener<String>() {
@Override
public void onResponse(String s) {
progressDialog.dismiss();
try {
JSONObject jsonObject = new JSONObject(s);
JSONArray array = jsonObject.getJSONArray("dates");
for(int i=0; i<array.length(); i++)
{
JSONObject o = array.getJSONObject(i);
CespiteOgg item = new CespiteOgg(
o.getString("CodNumInventario"),
o.getString("Nome"),
o.getString("DtCatalogazione"),
o.getString("CodIdA"),
o.getString("username")
);
cespiteOggList.add(item);
}
adapter = new CespiteAdapter(cespiteOggList, getActivity());
recyclerView.setAdapter(adapter);
} catch (JSONException e) {
e.printStackTrace();
}
}
},
new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
progressDialog.dismiss();
}
})
{
@Override
protected Map<String, String> getParams() throws AuthFailureError {
Map<String, String> params = new HashMap<String, String>();
params.put("Username", usernameUtente);
return params;
}
};
RegisterRequest.getmInstance(getActivity()).addToRequestque(stringRequest);
}
}
And it's the adapter:
public class CespiteAdapter extends RecyclerView.Adapter<CespiteAdapter.ViewHolder>
{
private List<CespiteOgg> cespiteOggList;
private Context context;
public CespiteAdapter(List<CespiteOgg> cespiteOggList, Context context) {
this.cespiteOggList = cespiteOggList;
this.context = context;
}
public class ViewHolder extends RecyclerView.ViewHolder
{
public CardView cv;
public TextView txtNumInventario;
public TextView txtNomeCespite;
public TextView txtDtCatalogazione;
public TextView txtAula;
public TextView txtNomeUser;
ViewHolder(View itemView)
{
super (itemView);
//cv = (CardView) itemView.findViewById(R.id.cardView);
txtNumInventario = (TextView) itemView.findViewById(R.id.txtNumeroInventario);
txtNomeCespite = (TextView) itemView.findViewById(R.id.txtNomeCespite);
txtDtCatalogazione = (TextView) itemView.findViewById(R.id.txtDataCatalogazione);
txtAula = (TextView) itemView.findViewById(R.id.txtAula);
txtNomeUser= (TextView) itemView.findViewById(R.id.txtNomeUser);
}
}
@Override
public CespiteAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType)
{
LayoutInflater inflater = LayoutInflater.from(parent.getContext());
View cespiteView = inflater.inflate(R.layout.cespite_card_view, parent, false);
return new ViewHolder(cespiteView);
}
@Override
public void onBindViewHolder(ViewHolder holder, int position)
{
CespiteOgg cespiteOgg = cespiteOggList.get(position);
holder.txtNumInventario.setText(cespiteOgg.getNumInventario());
holder.txtNomeCespite.setText(cespiteOgg.getNomeCespite());
holder.txtDtCatalogazione.setText(cespiteOgg.getDtCatalogazione());
holder.txtAula.setText(cespiteOgg.getAula());
holder.txtNomeUser.setText(cespiteOgg.getNomeUser());
}
@Override
public int getItemCount()
{
return cespiteOggList.size();
}
}
You can use android SwipeRefreshLayout widget instead of ProgressDialog.
Follow below steps to integrate SwipeRefreshLayout in your Tab1history fragment:
1. In your layout tab1history, add SwipeRefreshLayout as a root layout and place RecyclewrView inside it.
// tab1history.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.SwipeRefreshLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/swipe_container"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.v7.widget.RecyclerView
android:id="@+id/my_recycler_view"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</android.support.v4.widget.SwipeRefreshLayout>
2. In your Tab1History fragment, use SwipeRefreshLayout as below to load data from server:
// Tab1History.java
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.widget.SwipeRefreshLayout;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import com.android.volley.Request;
import com.android.volley.Response;
import com.android.volley.toolbox.StringRequest;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.ArrayList;
public class Tab1History extends Fragment implements SwipeRefreshLayout.OnRefreshListener {
SwipeRefreshLayout mSwipeRefreshLayout;
private RecyclerView recyclerView;
private CespiteAdapter adapter;
UserSessionManager session;
private static final String URL_DATA = "http://mydata.php";
private List<CespiteOgg> cespiteOggList;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState)
{
View rootView = inflater.inflate(R.layout.tab1history, container, false);
recyclerView = (RecyclerView) rootView.findViewById(R.id.my_recycler_view);
recyclerView.setHasFixedSize(true);//every item of the RecyclerView has a fix size
recyclerView.setLayoutManager(new LinearLayoutManager(getContext()));
cespiteOggList = new ArrayList<>();
// SwipeRefreshLayout
mSwipeRefreshLayout = (SwipeRefreshLayout) rootView.findViewById(R.id.swipe_container);
mSwipeRefreshLayout.setOnRefreshListener(this);
mSwipeRefreshLayout.setColorSchemeResources(R.color.colorPrimary,
android.R.color.holo_green_dark,
android.R.color.holo_orange_dark,
android.R.color.holo_blue_dark);
/**
* Showing Swipe Refresh animation on activity create
* As animation won't start on onCreate, post runnable is used
*/
mSwipeRefreshLayout.post(new Runnable() {
@Override
public void run() {
mSwipeRefreshLayout.setRefreshing(true);
// Fetching data from server
loadRecyclerViewData();
}
});
return rootView;
}
/**
* This method is called when swipe refresh is pulled down
*/
@Override
public void onRefresh() {
// Fetching data from server
loadRecyclerViewData();
}
private void loadRecyclerViewData()
{
// Showing refresh animation before making http call
mSwipeRefreshLayout.setRefreshing(true);
// Session class instance
session = new UserSessionManager(getActivity());
//get user data from session
HashMap<String, String> user = session.getUserDetails();
//get name
String name = user.get(UserSessionManager.KEY_NAME);
// get username
final String usernameUtente = user.get(UserSessionManager.KEY_USERNAME);
StringRequest stringRequest = new StringRequest(Request.Method.POST,
URL_DATA,
new Response.Listener<String>() {
@Override
public void onResponse(String s) {
try {
JSONObject jsonObject = new JSONObject(s);
JSONArray array = jsonObject.getJSONArray("dates");
for(int i=0; i<array.length(); i++)
{
JSONObject o = array.getJSONObject(i);
CespiteOgg item = new CespiteOgg(
o.getString("CodNumInventario"),
o.getString("Nome"),
o.getString("DtCatalogazione"),
o.getString("CodIdA"),
o.getString("username")
);
cespiteOggList.add(item);
}
adapter = new CespiteAdapter(cespiteOggList, getActivity());
recyclerView.setAdapter(adapter);
} catch (JSONException e) {
e.printStackTrace();
}
// Stopping swipe refresh
mSwipeRefreshLayout.setRefreshing(false);
}
},
new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
// Stopping swipe refresh
mSwipeRefreshLayout.setRefreshing(false);
}
})
{
@Override
protected Map<String, String> getParams() throws AuthFailureError {
Map<String, String> params = new HashMap<String, String>();
params.put("Username", usernameUtente);
return params;
}
};
RegisterRequest.getmInstance(getActivity()).addToRequestque(stringRequest);
}
}
Hope this will work properly.