How to use get getApplicationContext() in Adapter Class

Question

I am using Firebase to populate my BlogRecycleadapter with blog post and get Likes from Like Buttons but when device is offline and user press Like Button , then app crashes...So I'm trying to implement second condition of isNetworkavailaible too in if statement ..as below

if (!task.getResult().exists() && isNetworkStatusAvialable(getApplicationContext())){

                        Map<String, Object> likesMap = new HashMap<>();
                        likesMap.put("timestamp", FieldValue.serverTimestamp());


                        firebaseFirestore.collection("Posts/" + blogPostId + "/Likes").document(currentUserId).set(likesMap);

                    } else {
                        firebaseFirestore.collection("Posts/" + blogPostId + "/Likes").document(currentUserId).delete();

                    }

But I'm gettning errror in getApplicationContext(), from few google search , I found that getApplicationContext() is not availaibe for Class but only for activity.

So how can I implement getApplicationContext here??

My whole code of Recycle adapter is

package com.nepalpolice.cdp;

import android.content.Context;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.Build;
import android.support.annotation.NonNull;
import android.support.v7.widget.RecyclerView;
import android.text.format.DateFormat;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;

import com.bumptech.glide.Glide;
import com.bumptech.glide.request.RequestOptions;
import com.google.android.gms.tasks.OnCompleteListener;
import com.google.android.gms.tasks.Task;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.firestore.DocumentSnapshot;
import com.google.firebase.firestore.EventListener;
import com.google.firebase.firestore.FieldValue;
import com.google.firebase.firestore.FirebaseFirestore;
import com.google.firebase.firestore.FirebaseFirestoreException;
import com.google.firebase.firestore.QuerySnapshot;

import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import de.hdodenhof.circleimageview.CircleImageView;

public class BlogRecyclerAdapter extends RecyclerView.Adapter<BlogRecyclerAdapter.ViewHolder> {

    public List<BlogPost> blog_list;
    public Context context;

    private FirebaseFirestore firebaseFirestore;
private FirebaseAuth firebaseAuth;


    public BlogRecyclerAdapter(List<BlogPost> blog_list,Context context){

        this.blog_list = blog_list;
        this.context=context;

    }

    @Override
    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.blog_list_item, parent, false);
        context = parent.getContext();
        firebaseFirestore = FirebaseFirestore.getInstance();
        firebaseAuth = FirebaseAuth.getInstance();
        return new ViewHolder(view);
    }

    @Override
    public void onBindViewHolder(final ViewHolder holder, int position) {

        holder.setIsRecyclable(false);

        final String blogPostId = blog_list.get(position).BlogPostId;
        final String currentUserId = firebaseAuth.getCurrentUser().getUid();

        String desc_data = blog_list.get(position).getDesc();
        holder.setDescText(desc_data);

        String image_url = blog_list.get(position).getImage_url();
        holder.setBlogImage(image_url);

        String user_id = blog_list.get(position).getUser_id();
        //User Data will be retrieved here...
        firebaseFirestore.collection("Users").document(user_id).get().addOnCompleteListener(new OnCompleteListener<DocumentSnapshot>() {
            @Override
            public void onComplete(@NonNull Task<DocumentSnapshot> task) {

                if(task.isSuccessful()){

                    String userName = task.getResult().getString("name");
                    String userImage = task.getResult().getString("image");

                    holder.setUserData(userName, userImage);


                } else {

                    //Firebase Exception

                }

            }
        });

        long millisecond = blog_list.get(position).getTimestamp().getTime();
        String dateString = DateFormat.format("MM/dd/yyyy", new Date(millisecond)).toString();
        holder.setTime(dateString);

        //Get Likes Count
        firebaseFirestore.collection("Posts/" + blogPostId + "/Likes").addSnapshotListener(((Main2Activity) context),new EventListener<QuerySnapshot>() {
            @Override
            public void onEvent(QuerySnapshot documentSnapshots, FirebaseFirestoreException e) {

                if (!documentSnapshots.isEmpty()){

int count = documentSnapshots.size();
holder.updateLikesCount(count);

                }else{
holder.updateLikesCount(0);

                }

            }
        });



        //Get Likes

        firebaseFirestore.collection("Posts/" + blogPostId + "/Likes").document(currentUserId).addSnapshotListener(((Main2Activity) context),new EventListener<DocumentSnapshot>() {
            @Override
            public void onEvent(DocumentSnapshot documentSnapshot, FirebaseFirestoreException e) {

                if (documentSnapshot.exists()){

                    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
                        holder.blogLikeBtn.setImageDrawable(context.getDrawable(R.mipmap.action_like_accent));
                    }
                    else {
                        holder.blogLikeBtn.setImageDrawable(context.getResources().getDrawable(R.mipmap.action_like_accent));
                    }
                } else {

                    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
                        holder.blogLikeBtn.setImageDrawable(context.getDrawable(R.mipmap.action_like_gray));
                    }else{
                        holder.blogLikeBtn.setImageDrawable(context.getResources().getDrawable(R.mipmap.action_like_gray));
                    }
                }

            }
        });

        //like Feature



        holder.blogLikeBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {



                firebaseFirestore.collection("Posts/" + blogPostId + "/Likes").document(currentUserId).get().addOnCompleteListener(new OnCompleteListener<DocumentSnapshot>() {
                    @Override
                    public void onComplete(@NonNull Task<DocumentSnapshot> task) {
                        if (!task.getResult().exists() && isNetworkStatusAvialable(getApplicationContext())){

                            Map<String, Object> likesMap = new HashMap<>();
                            likesMap.put("timestamp", FieldValue.serverTimestamp());


                            firebaseFirestore.collection("Posts/" + blogPostId + "/Likes").document(currentUserId).set(likesMap);

                        } else {
                            firebaseFirestore.collection("Posts/" + blogPostId + "/Likes").document(currentUserId).delete();

                        }

                    }
                });



            }
        });

    }

    @Override
    public int getItemCount() {

        return blog_list.size();
    }

    public class ViewHolder extends RecyclerView.ViewHolder {

        private View mView;

        private TextView descView;
        private ImageView blogImageView;
        private TextView blogDate;

        private TextView blogUserName;
        private CircleImageView blogUserImage;
        private ImageView blogLikeBtn;
        private  TextView blogLikeCount;

        public ViewHolder(View itemView) {
            super(itemView);
            mView = itemView;



        }

        public void setDescText(String descText){

            descView = mView.findViewById(R.id.blog_desc);
            descView.setText(descText);

            blogLikeBtn = mView.findViewById(R.id.blog_like_btn);
        }

        public void setBlogImage(String downloadUri){

            blogImageView = mView.findViewById(R.id.blog_image);
            RequestOptions requestOptions = new RequestOptions();
            requestOptions.placeholder(R.drawable.image_placeholder);
            Glide.with(context).applyDefaultRequestOptions(requestOptions).load(downloadUri).into(blogImageView);

        }

        public void setTime(String date) {

            blogDate = mView.findViewById(R.id.blog_date);
            blogDate.setText(date);

        }

        public void setUserData(String name, String image){

            blogUserImage = mView.findViewById(R.id.blog_user_image);
            blogUserName = mView.findViewById(R.id.blog_user_name);

            blogUserName.setText(name);

            RequestOptions placeholderOption = new RequestOptions();
            placeholderOption.placeholder(R.drawable.profile_placeholder);

            Glide.with(context).applyDefaultRequestOptions(placeholderOption).load(image).into(blogUserImage);

        }

public void  updateLikesCount (int count){

            blogLikeCount = mView.findViewById(R.id.blog_like_count);
            blogLikeCount.setText(count + "Likes");
}

    }
    public static boolean isNetworkStatusAvialable (Context context) {
        ConnectivityManager cm =
                (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);

        NetworkInfo activeNetwork = cm.getActiveNetworkInfo();
        return activeNetwork != null &&
                activeNetwork.isConnectedOrConnecting();

    }
}

and my HOmeFragment from where I'm calling adapter class is

package com.nepalpolice.cdp;


import android.os.Bundle;
import android.support.v4.app.Fragment;
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 android.widget.Toast;

import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.firestore.DocumentChange;
import com.google.firebase.firestore.DocumentSnapshot;
import com.google.firebase.firestore.EventListener;
import com.google.firebase.firestore.FirebaseFirestore;
import com.google.firebase.firestore.FirebaseFirestoreException;
import com.google.firebase.firestore.Query;
import com.google.firebase.firestore.QuerySnapshot;

import java.util.ArrayList;
import java.util.List;


/**
 * A simple {@link Fragment} subclass.
 */
public class HomeFragment extends Fragment {

    private RecyclerView blog_list_view;
    private List<BlogPost> blog_list;

    private FirebaseFirestore firebaseFirestore;
    private FirebaseAuth firebaseAuth;
    private BlogRecyclerAdapter blogRecyclerAdapter;

    private DocumentSnapshot lastVisible;
    private Boolean isFirstPageFirstLoad = true;

    public HomeFragment() {
        // Required empty public constructor
    }


    @Override
    public View onCreateView(LayoutInflater inflater, final ViewGroup container,
                             Bundle savedInstanceState) {

        View view = inflater.inflate(R.layout.fragment_home, container, false);

        blog_list = new ArrayList<>();
        blog_list_view = view.findViewById(R.id.blog_list_view);

        firebaseAuth = FirebaseAuth.getInstance();

        blogRecyclerAdapter = new BlogRecyclerAdapter(blog_list);
        blog_list_view.setLayoutManager(new LinearLayoutManager(container.getContext()));
        blog_list_view.setAdapter(blogRecyclerAdapter);

        if(firebaseAuth.getCurrentUser() != null) {

            firebaseFirestore = FirebaseFirestore.getInstance();

            blog_list_view.addOnScrollListener(new RecyclerView.OnScrollListener() {
                @Override
                public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
                    super.onScrolled(recyclerView, dx, dy);

                    Boolean reachedBottom = !recyclerView.canScrollVertically(1);

                    if(reachedBottom){

                        String desc = lastVisible.getString("desc");
                        Toast.makeText(container.getContext(), "Reached : " + desc, Toast.LENGTH_SHORT).show();

                        loadMorePost();

                    }

                }
            });

            Query firstQuery = firebaseFirestore.collection("Posts").orderBy("timestamp", Query.Direction.DESCENDING).limit(3);
            firstQuery.addSnapshotListener(getActivity(), new EventListener<QuerySnapshot>() {
                @Override
                public void onEvent(QuerySnapshot documentSnapshots, FirebaseFirestoreException e) {
                    if (isFirstPageFirstLoad){

                        lastVisible = documentSnapshots.getDocuments().get(documentSnapshots.size() - 1);

                    }
                    for (DocumentChange doc : documentSnapshots.getDocumentChanges()){
                        if (doc.getType() == DocumentChange.Type.ADDED) {

                            String blogPostId = doc.getDocument().getId();
                            BlogPost blogPost = doc.getDocument().toObject(BlogPost.class).withId(blogPostId);

                            if (isFirstPageFirstLoad){
                                blog_list.add(blogPost);

                            }else {
                                blog_list.add(0,blogPost);

                            }
                           blogRecyclerAdapter.notifyDataSetChanged();;
                        }
                    }
isFirstPageFirstLoad = false;
                }
            });

        }

        // Inflate the layout for this fragment
        return view;
    }

    public void loadMorePost(){

        Query nextQuery = firebaseFirestore.collection("Posts")
                .orderBy("timestamp", Query.Direction.DESCENDING)
                .startAfter(lastVisible)
                .limit(3);

        nextQuery.addSnapshotListener(getActivity(), new EventListener<QuerySnapshot>() {
            @Override
            public void onEvent(QuerySnapshot documentSnapshots, FirebaseFirestoreException e) {

                    if (!documentSnapshots.isEmpty()){


                        lastVisible = documentSnapshots.getDocuments().get(documentSnapshots.size() - 1);
                    for (DocumentChange doc : documentSnapshots.getDocumentChanges()) {
                        if (doc.getType() == DocumentChange.Type.ADDED) {
                            String blogPostId = doc.getDocument().getId();
                            BlogPost blogPost = doc.getDocument().toObject(BlogPost.class).withId(blogPostId);
                            blog_list.add(blogPost);

                            blogRecyclerAdapter.notifyDataSetChanged();

                        }
                    }

                }

            }
        });

    }

}

Thanks in advance.

refer this link https://stackoverflow.com/questions/21818905/get-application-context-from-non-activity-singleton-class/21819009?utm_medium=organic&utm_source=google_rich_qa&utm_campaign=google_rich_qa — Ali, Mar 26 '18 at 13:23

AskNilesh · Answer 1 · 2018-03-26T13:28:10.453

4

Try this

You can pass Context in your Constructor of your BlogRecyclerAdapter

public BlogRecyclerAdapter(List < BlogPost > blog_list, Context context) {

    this.blog_list = blog_list;
    this.context = context;

 }

use like this

firebaseFirestore = FirebaseFirestore.getInstance(context);
firebaseAuth = FirebaseAuth.getInstance(context);



Glide.with(context).applyDefaultRequestOptions(placeholderOption).load(image).into(blogUserImage);

call your BlogRecyclerAdapter like this

BlogRecyclerAdapter adapter= new BlogRecyclerAdapter( blog_list, YourActivity.this );

edited Mar 26 '18 at 13:28

answered Mar 26 '18 at 13:20

AskNilesh

67,701
16
123
163

I have no idea where should or how should I add your method on above code or implement this solution. Sorry could you please explain it bit more and where is isNetworkStatusAvialable method applied here?? – nEwyeTi Mar 26 '18 at 14:15

007 · Answer 2 · 2018-03-26T14:58:00.090

0

Create a Adapter constructor and at the time of sending list data send one another parameter context from main class.

this in Fragment

 blogRecyclerAdapter = new BlogRecyclerAdapter(blog_list,getContext());
        blog_list_view.setLayoutManager(new LinearLayoutManager(container.getContext()));
        blog_list_view.setAdapter(blogRecyclerAdapter);

this is in adapter

public BlogRecyclerAdapter(List<BlogPost> blog_list,Context context){
  this.blog_list = blog_list;
  this.context=context;
}

Then you can use this context as getApplicationContext(); in adapter class

disable button at the time of no internet.

if(!isNetworkAvailable()){
like_btn.setClickable(false); }

private boolean isNetworkAvailable() {
    ConnectivityManager connectivityManager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo activeNetworkInfo = connectivityManager.getActiveNetworkInfo();
    return activeNetworkInfo != null && activeNetworkInfo.isConnected();
}

edited Mar 26 '18 at 14:58

answered Mar 26 '18 at 13:21

007

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How do I implement this....I did as you suggested but still I'm getting error of getApplicationContext() can't be resolved error...Please see my updated code above. – nEwyeTi Mar 26 '18 at 14:09
Where is your main class from where you are calling adapter class?? – 007 Mar 26 '18 at 14:17
I'm calling from Fragment..I have again updated my answer. Please check . – nEwyeTi Mar 26 '18 at 14:20
Tha solved the error probelm...but I realized that it won't provide me anysolution....is there any way i could disable onClicklistener of like_btn when user is offline with isNetowkravailaible method?? – nEwyeTi Mar 26 '18 at 14:53
check the answer @nEwyeTi – 007 Mar 26 '18 at 15:02
still I'm getting error or getSystemService can't be solved and !isNetworkAvailable is also invalid declaration return type required. – nEwyeTi Mar 26 '18 at 15:19
have you added internet permisson? – 007 Mar 26 '18 at 15:22

score 0 · Answer 3 · answered Mar 26 '18 at 13:32

0

Without sending parameter you can achecive the same thing when you are calling your network checking method use your method like below

isNetworkStatusAvialable( holder.blogLikeBtn.getContext())

Instead of passing getApplicationContext() method you can get the context from any view that you have.

By using above approach, I am passing context of the same button that was clicked. Hope that helps you as well.

answered Mar 26 '18 at 13:32

Abdul Waheed

4,540
6
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Thanks for help..but where should I add above method?? I'm very new to android and java.....I'm learning from Tutorials and examples....so I couldn't apply above method anywhere..Please suggest. – nEwyeTi Mar 26 '18 at 14:10
the area where you are calling isNetworkStatusAvialable() method there you need to use the view to get context – Abdul Waheed Mar 26 '18 at 14:32
can you help me with example, hence it'd be more clear for me and others in future seeking out for same help. – nEwyeTi Mar 26 '18 at 14:38

How to use get getApplicationContext() in Adapter Class

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