Esta es la Parte 13 del tutorial «Crear una aplicación de redes sociales en Android Studio» , y vamos a cubrir las siguientes funcionalidades en este artículo:
- Vamos a eliminar el Blog escrito por el usuario.
- Los blogs solo pueden ser eliminados por el propietario de los blogs. En la parte superior derecha del blog, hay un botón.
- Después de hacer clic en eso, aparecerá una ventana emergente en la que aparecerá el botón Eliminar. Después de hacer clic en Eliminar, el blog se eliminará con éxito de los blogs.
Implementación paso a paso
Paso 1: trabajar con el archivo AdapterPosts.java
Obtendremos el Node dentro de las “Publicaciones” que queremos eliminar. Estamos eliminando directamente el valor de referencia de la instantánea.
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) {
}
});
A continuación se muestra el código actualizado para el archivo AdapterPosts.java .
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);
}
}
}
Producción:
Para ver todos los archivos dibujables utilizados en este artículo, consulte este enlace: https://drive.google.com/drive/folders/1M_knOH_ugCuwSP5nkYzeD4dRp-Honzbe?usp=sharing
A continuación se muestra la estructura de archivos después de realizar estas operaciones:
