This is the Part 13 of “Build a Social Media App on Android Studio” tutorial, and we are going to cover the following functionalities in this article:
- We are going to delete the Blog written by the user.
- Blogs can only be deleted by the owner of blogs. In the top right of the blog, a button is there.
- After clicking on that a popup will come in that Delete button will come. After clicking on Delete, the blog will be successfully deleted from the blogs.
Step By Step Implementation
Step 1: Working with the AdapterPosts.java file
We will get the node inside the “Posts” which we want to delete. We are directly deleting the snapshot reference value.
Query query= FirebaseDatabase.getInstance().getReference("Posts").orderByChild("ptime").equalTo(pid);
query.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
for (DataSnapshot dataSnapshot1:dataSnapshot.getChildren()){
dataSnapshot1.getRef().removeValue();//removing the value after getting reference
}
pd.dismiss();
Toast.makeText(context,"Deleted Successfully",Toast.LENGTH_LONG).show();
}
@Override
public void onCancelled(@NonNull DatabaseError databaseError) {
}
});
Below is the updated code for the AdapterPosts.java file.
Java
package com.example.socialmediaapp;import android.app.ProgressDialog;import android.content.Context;import android.content.Intent;import android.text.format.DateFormat;import android.view.Gravity;import android.view.LayoutInflater;import android.view.Menu;import android.view.MenuItem;import android.view.View;import android.view.ViewGroup;import android.widget.Button;import android.widget.ImageButton;import android.widget.ImageView;import android.widget.LinearLayout;import android.widget.PopupMenu;import android.widget.TextView;import android.widget.Toast;import androidx.annotation.NonNull;import androidx.recyclerview.widget.RecyclerView;import com.bumptech.glide.Glide;import com.google.android.gms.tasks.OnFailureListener;import com.google.android.gms.tasks.OnSuccessListener;import com.google.firebase.auth.FirebaseAuth;import com.google.firebase.database.DataSnapshot;import com.google.firebase.database.DatabaseError;import com.google.firebase.database.DatabaseReference;import com.google.firebase.database.FirebaseDatabase;import com.google.firebase.database.Query;import com.google.firebase.database.ValueEventListener;import com.google.firebase.storage.FirebaseStorage;import com.google.firebase.storage.StorageReference;import java.util.Calendar;import java.util.List;import java.util.Locale;public class AdapterPosts extends RecyclerView.Adapter<AdapterPosts.MyHolder> { Context context; String myuid; private DatabaseReference liekeref, postref; boolean mprocesslike = false; public AdapterPosts(Context context, List<ModelPost> modelPosts) { this.context = context; this.modelPosts = modelPosts; myuid = FirebaseAuth.getInstance().getCurrentUser().getUid(); liekeref = FirebaseDatabase.getInstance().getReference().child("Likes"); postref = FirebaseDatabase.getInstance().getReference().child("Posts"); } List<ModelPost> modelPosts; @NonNull @Override public MyHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) { View view = LayoutInflater.from(context).inflate(R.layout.row_posts, parent, false); return new MyHolder(view); } @Override public void onBindViewHolder(@NonNull final MyHolder holder, final int position) { final String uid = modelPosts.get(position).getUid(); String nameh = modelPosts.get(position).getUname(); final String titlee = modelPosts.get(position).getTitle(); final String descri = modelPosts.get(position).getDescription(); final String ptime = modelPosts.get(position).getPtime(); String dp = modelPosts.get(position).getUdp(); String plike = modelPosts.get(position).getPlike(); final String image = modelPosts.get(position).getUimage(); String email = modelPosts.get(position).getUemail(); String comm = modelPosts.get(position).getPcomments(); final String pid = modelPosts.get(position).getPtime(); Calendar calendar = Calendar.getInstance(Locale.ENGLISH); calendar.setTimeInMillis(Long.parseLong(ptime)); String timedate = DateFormat.format("dd/MM/yyyy hh:mm aa", calendar).toString(); holder.name.setText(nameh); holder.title.setText(titlee); holder.description.setText(descri); holder.time.setText(timedate); holder.like.setText(plike + " Likes"); holder.comments.setText(comm + " Comments"); setLikes(holder, ptime); try { Glide.with(context).load(dp).into(holder.picture); } catch (Exception e) { } holder.image.setVisibility(View.VISIBLE); try { Glide.with(context).load(image).into(holder.image); } catch (Exception e) { } holder.like.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { Intent intent = new Intent(holder.itemView.getContext(), PostLikedByActivity.class); intent.putExtra("pid", pid); holder.itemView.getContext().startActivity(intent); } }); holder.likebtn.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { final int plike = Integer.parseInt(modelPosts.get(position).getPlike()); mprocesslike = true; final String postid = modelPosts.get(position).getPtime(); liekeref.addValueEventListener(new ValueEventListener() { @Override public void onDataChange(@NonNull DataSnapshot dataSnapshot) { if (mprocesslike) { if (dataSnapshot.child(postid).hasChild(myuid)) { postref.child(postid).child("plike").setValue("" + (plike - 1)); liekeref.child(postid).child(myuid).removeValue(); mprocesslike = false; } else { postref.child(postid).child("plike").setValue("" + (plike + 1)); liekeref.child(postid).child(myuid).setValue("Liked"); mprocesslike = false; } } } @Override public void onCancelled(@NonNull DatabaseError databaseError) { } }); } }); holder.more.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { showMoreOptions(holder.more, uid, myuid, ptime, image); } }); holder.comment.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { Intent intent = new Intent(context, PostDetailsActivity.class); intent.putExtra("pid", ptime); context.startActivity(intent); } }); } private void showMoreOptions(ImageButton more, String uid, String myuid, final String pid, final String image) { PopupMenu popupMenu = new PopupMenu(context, more, Gravity.END); if (uid.equals(myuid)) { popupMenu.getMenu().add(Menu.NONE, 0, 0, "DELETE"); } popupMenu.setOnMenuItemClickListener(new PopupMenu.OnMenuItemClickListener() { @Override public boolean onMenuItemClick(MenuItem item) { if (item.getItemId() == 0) { deltewithImage(pid, image); } return false; } }); popupMenu.show(); } private void deltewithImage(final String pid, String image) { final ProgressDialog pd = new ProgressDialog(context); pd.setMessage("Deleting"); StorageReference picref = FirebaseStorage.getInstance().getReferenceFromUrl(image); picref.delete().addOnSuccessListener(new OnSuccessListener<Void>() { @Override public void onSuccess(Void aVoid) { Query query = FirebaseDatabase.getInstance().getReference("Posts").orderByChild("ptime").equalTo(pid); query.addValueEventListener(new ValueEventListener() { @Override public void onDataChange(@NonNull DataSnapshot dataSnapshot) { for (DataSnapshot dataSnapshot1 : dataSnapshot.getChildren()) { dataSnapshot1.getRef().removeValue(); } pd.dismiss(); Toast.makeText(context, "Deleted Successfully", Toast.LENGTH_LONG).show(); } @Override public void onCancelled(@NonNull DatabaseError databaseError) { } }); } }).addOnFailureListener(new OnFailureListener() { @Override public void onFailure(@NonNull Exception e) { } }); } private void setLikes(final MyHolder holder, final String pid) { liekeref.addValueEventListener(new ValueEventListener() { @Override public void onDataChange(@NonNull DataSnapshot dataSnapshot) { if (dataSnapshot.child(pid).hasChild(myuid)) { holder.likebtn.setCompoundDrawablesWithIntrinsicBounds(R.drawable.ic_liked, 0, 0, 0); holder.likebtn.setText("Liked"); } else { holder.likebtn.setCompoundDrawablesWithIntrinsicBounds(R.drawable.ic_like, 0, 0, 0); holder.likebtn.setText("Like"); } } @Override public void onCancelled(@NonNull DatabaseError databaseError) { } }); } @Override public int getItemCount() { return modelPosts.size(); } class MyHolder extends RecyclerView.ViewHolder { ImageView picture, image; TextView name, time, title, description, like, comments; ImageButton more; Button likebtn, comment; LinearLayout profile; public MyHolder(@NonNull View itemView) { super(itemView); picture = itemView.findViewById(R.id.picturetv); image = itemView.findViewById(R.id.pimagetv); name = itemView.findViewById(R.id.unametv); time = itemView.findViewById(R.id.utimetv); more = itemView.findViewById(R.id.morebtn); title = itemView.findViewById(R.id.ptitletv); description = itemView.findViewById(R.id.descript); like = itemView.findViewById(R.id.plikeb); comments = itemView.findViewById(R.id.pcommentco); likebtn = itemView.findViewById(R.id.like); comment = itemView.findViewById(R.id.comment); profile = itemView.findViewById(R.id.profilelayout); } }} |
Output:
For all the drawable file used in this article please refer to this link: https://drive.google.com/drive/folders/1M_knOH_ugCuwSP5nkYzeD4dRp-Honzbe?usp=sharing
Below is the file structure after performing these operations:
