¿Cómo actualizar datos en Firebase Firestore en Android?

En el artículo anterior, hemos visto Cómo agregar datos a Firebase Firestore en Android , Cómo leer los datos de Firebase Firestore en Android . Ahora veremos Cómo actualizar estos datos agregados dentro de nuestro Firebase Firestore . Ahora avanzaremos hacia la implementación de esta actualización de datos en Android Firebase.  

¿Qué vamos a construir en este artículo?  

Crearemos una pantalla similar a la que estábamos creando para agregar los datos y dentro de esta pantalla, actualizaremos nuestros datos dentro de nuestro Firebase Firestore y esos datos también se actualizarán dentro de nuestra aplicación. 

Implementación paso a paso

Paso 1: crear una nueva actividad para actualizar los datos

Para crear una nueva actividad, vaya a la aplicación > res > diseño > Haga clic con el botón derecho en él y haga clic en Nuevo > luego haga clic en Actividad vacía para crear una nueva actividad y la nombraremos como UpdateCourse . Después de crear una nueva Actividad, vaya a la aplicación > res > diseño > activity_update_course.xml y agréguele el siguiente código. 

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".UpdateCourse">
  
    <!--Edittext for getting course Name-->
    <EditText
        android:id="@+id/idEdtCourseName"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginStart="10dp"
        android:layout_marginTop="20dp"
        android:layout_marginEnd="10dp"
        android:hint="Course Name"
        android:importantForAutofill="no"
        android:inputType="text" />
  
    <!--Edittext for getting course Duration-->
    <EditText
        android:id="@+id/idEdtCourseDuration"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginStart="10dp"
        android:layout_marginTop="20dp"
        android:layout_marginEnd="10dp"
        android:hint="Course Duration in min"
        android:importantForAutofill="no"
        android:inputType="time" />
  
    <!--Edittext for getting course Description-->
    <EditText
        android:id="@+id/idEdtCourseDescription"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginStart="10dp"
        android:layout_marginTop="20dp"
        android:layout_marginEnd="10dp"
        android:hint="Course Description"
        android:importantForAutofill="no"
        android:inputType="text" />
  
  
    <!--Button for updating your course to Firebase-->
    <Button
        android:id="@+id/idBtnUpdateCourse"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="10dp"
        android:text="Update Course Details"
        android:textAllCaps="false" />
  
</LinearLayout>

Paso 2: Actualizar nuestra clase modal donde almacenamos nuestros datos 

En artículos anteriores, hemos visto crear nuestra clase Modal. En este artículo, actualizaremos nuestra clase Modal para que podamos pasar nuestra clase de objeto del adaptador a nuestra actividad para la navegación. Junto con la implementación de serializable , tenemos que crear una nueva variable de string y crear un getter y setter para esa variable. Usaremos esa variable para almacenar la identificación de nuestro documento. A continuación se muestra el código de la clase Courses.java actualizada . Se agregan comentarios dentro del código para conocerlo con más detalle. 

import com.google.firebase.firestore.Exclude;
  
import java.io.Serializable;
  
// we have to implement our modal class
// with serializable so that we can pass
// our object class to new activity on
// our item click of recycler view.
public class Courses implements Serializable {
  
    // getter method for our id
    public String getId() {
        return id;
    }
  
    // setter method for our id
    public void setId(String id) {
        this.id = id;
    }
  
    // we are using exclude because
    // we are not saving our id
    @Exclude
    private String id;
      
    // variables for storing our data.
    private String courseName, courseDescription, courseDuration;
  
    public Courses() {
        // empty constructor required for Firebase.
    }
  
    // Constructor for all variables.
    public Courses(String courseName, String courseDescription, String courseDuration) {
        this.courseName = courseName;
        this.courseDescription = courseDescription;
        this.courseDuration = courseDuration;
    }
  
    // getter methods for all variables.
    public String getCourseName() {
        return courseName;
    }
  
    public void setCourseName(String courseName) {
        this.courseName = courseName;
    }
  
    public String getCourseDescription() {
        return courseDescription;
    }
  
    // setter method for all variables.
    public void setCourseDescription(String courseDescription) {
        this.courseDescription = courseDescription;
    }
  
    public String getCourseDuration() {
        return courseDuration;
    }
  
    public void setCourseDuration(String courseDuration) {
        this.courseDuration = courseDuration;
    }
}

Paso 3: Agregar onClickListener() para nuestros elementos de RecyclerView

Como hemos creado nuestra clase Adapter en el artículo anterior para mostrar la lista de cursos en Recycler View. En este artículo, agregaremos onClickListener() dentro de esa clase Adapter para el detector de clics del elemento RecyclerView. Agregue el siguiente fragmento de código al archivo CourseRVAdapter.java .

// here we are adding on click listener
// for our item of recycler view.
itemView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    
                    // after clicking of the item of recycler view.
                    // we are passing our course object to the new activity.
                    Courses courses = coursesArrayList.get(getAdapterPosition());
  
                    // below line is creating a new intent.
                    Intent i = new Intent(context, UpdateCourse.class);
  
                    // below line is for putting our course object to our next activity.
                    i.putExtra("course", courses);
  
                    // after passing the data we are starting our activity.
                    context.startActivity(i);
           }
    });

A continuación se muestra el código actualizado para el archivo CourseRVAdapter.java .

import android.content.Context;
import android.content.Intent;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
  
import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;
  
import java.util.ArrayList;
  
public class CourseRVAdapter extends RecyclerView.Adapter<CourseRVAdapter.ViewHolder> {
    // creating variables for our ArrayList and context
    private ArrayList<Courses> coursesArrayList;
    private Context context;
  
    // creating constructor for our adapter class
    public CourseRVAdapter(ArrayList<Courses> coursesArrayList, Context context) {
        this.coursesArrayList = coursesArrayList;
        this.context = context;
    }
  
    @NonNull
    @Override
    public CourseRVAdapter.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        // passing our layout file for displaying our card item
        return new ViewHolder(LayoutInflater.from(context).inflate(R.layout.course_item, parent, false));
    }
  
    @Override
    public void onBindViewHolder(@NonNull CourseRVAdapter.ViewHolder holder, int position) {
        // setting data to our text views from our modal class.
        Courses courses = coursesArrayList.get(position);
        holder.courseNameTV.setText(courses.getCourseName());
        holder.courseDurationTV.setText(courses.getCourseDuration());
        holder.courseDescTV.setText(courses.getCourseDescription());
    }
  
    @Override
    public int getItemCount() {
        // returning the size of our array list.
        return coursesArrayList.size();
    }
  
    class ViewHolder extends RecyclerView.ViewHolder {
        // creating variables for our text views.
        private final TextView courseNameTV;
        private final TextView courseDurationTV;
        private final TextView courseDescTV;
  
        public ViewHolder(@NonNull View itemView) {
            super(itemView);
            // initializing our text views.
            courseNameTV = itemView.findViewById(R.id.idTVCourseName);
            courseDurationTV = itemView.findViewById(R.id.idTVCourseDuration);
            courseDescTV = itemView.findViewById(R.id.idTVCourseDescription);
  
            // here we are adding on click listener
            // for our item of recycler view.
            itemView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    
                    // after clicking of the item of recycler view.
                    // we are passing our course object to the new activity.
                    Courses courses = coursesArrayList.get(getAdapterPosition());
  
                    // below line is creating a new intent.
                    Intent i = new Intent(context, UpdateCourse.class);
  
                    // below line is for putting our course object to our next activity.
                    i.putExtra("course", courses);
  
                    // after passing the data we are starting our activity.
                    context.startActivity(i);
                }
            });
        }
    }
}

Paso 4: Actualice el código en el archivo CourseDetails.java 

Como hemos creado una nueva variable dentro de nuestra clase modal para almacenar la identificación del documento, debemos inicializar esa variable y pasar nuestra identificación del documento dentro de esa variable. Para pasar esa identificación de documento, debemos actualizar nuestro código para el archivo CourseDetails.java donde mostramos la lista de todos los cursos que hemos agregado. Agregue el siguiente fragmento de código al archivo CourseRVAdapter.java .

// below is the updated line of code which we have to
// add to pass the document id inside our modal class.
// we are setting our document id with d.getId() method
c.setId(d.getId());

A continuación se muestra el código actualizado para el archivo CourseDetails.java .

import android.os.Bundle;
import android.view.View;
import android.widget.ProgressBar;
import android.widget.Toast;
  
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
  
import com.google.android.gms.tasks.OnFailureListener;
import com.google.android.gms.tasks.OnSuccessListener;
import com.google.firebase.firestore.DocumentSnapshot;
import com.google.firebase.firestore.FirebaseFirestore;
import com.google.firebase.firestore.QuerySnapshot;
  
import java.util.ArrayList;
import java.util.List;
  
public class CourseDetails extends AppCompatActivity {
  
    // creating variables for our recycler view,
    // array list, adapter, firebase firestore
    // and our progress bar.
    private RecyclerView courseRV;
    private ArrayList<Courses> coursesArrayList;
    private CourseRVAdapter courseRVAdapter;
    private FirebaseFirestore db;
    ProgressBar loadingPB;
  
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_course_details);
  
        // initializing our variables.
        courseRV = findViewById(R.id.idRVCourses);
        loadingPB = findViewById(R.id.idProgressBar);
  
        // initializing our variable for firebase
        // firestore and getting its instance.
        db = FirebaseFirestore.getInstance();
  
        // creating our new array list
        coursesArrayList = new ArrayList<>();
        courseRV.setHasFixedSize(true);
        courseRV.setLayoutManager(new LinearLayoutManager(this));
  
        // adding our array list to our recycler view adapter class.
        courseRVAdapter = new CourseRVAdapter(coursesArrayList, this);
  
        // setting adapter to our recycler view.
        courseRV.setAdapter(courseRVAdapter);
  
        // below line is use to get the data from Firebase Firestore.
        // previously we were saving data on a reference of Courses
        // now we will be getting the data from the same reference.
        db.collection("Courses").get()
                .addOnSuccessListener(new OnSuccessListener<QuerySnapshot>() {
                    @Override
                    public void onSuccess(QuerySnapshot queryDocumentSnapshots) {
                        // after getting the data we are calling on success method
                        // and inside this method we are checking if the received
                        // query snapshot is empty or not.
                        if (!queryDocumentSnapshots.isEmpty()) {
                            // if the snapshot is not empty we are
                            // hiding our progress bar and adding
                            // our data in a list.
                            loadingPB.setVisibility(View.GONE);
                            List<DocumentSnapshot> list = queryDocumentSnapshots.getDocuments();
                            for (DocumentSnapshot d : list) {
                                // after getting this list we are passing
                                // that list to our object class.
                                Courses c = d.toObject(Courses.class);
  
                                // below is the updated line of code which we have to
                                // add to pass the document id inside our modal class.
                                // we are setting our document id with d.getId() method
                                c.setId(d.getId());
  
                                // and we will pass this object class
                                // inside our arraylist which we have
                                // created for recycler view.
                                coursesArrayList.add(c);
                            }
                            // after adding the data to recycler view.
                            // we are calling recycler view notifuDataSetChanged
                            // method to notify that data has been changed in recycler view.
                            courseRVAdapter.notifyDataSetChanged();
                        } else {
                            // if the snapshot is empty we are displaying a toast message.
                            Toast.makeText(CourseDetails.this, "No data found in Database", Toast.LENGTH_SHORT).show();
                        }
                    }
                }).addOnFailureListener(new OnFailureListener() {
            @Override
            public void onFailure(@NonNull Exception e) {
                // if we do not get any data or any error we are displaying
                // a toast message that we do not get any data
                Toast.makeText(CourseDetails.this, "Fail to get the data.", Toast.LENGTH_SHORT).show();
            }
        });
    }
}

Paso 5: ahora avanzaremos hacia la implementación de nuestro archivo UpdateCourses.java

Después de actualizar nuestra clase Adapter, vaya a la aplicación > java > nombre del paquete de su aplicación > archivo UpdateCourses.java y agréguele el siguiente código. Se agregan comentarios dentro del código para comprender el código con más detalle.

import android.os.Bundle;
import android.text.TextUtils;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
  
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
  
import com.google.android.gms.tasks.OnFailureListener;
import com.google.android.gms.tasks.OnSuccessListener;
import com.google.firebase.firestore.FirebaseFirestore;
  
public class UpdateCourse extends AppCompatActivity {
  
    // creating variables for our edit text
    private EditText courseNameEdt, courseDurationEdt, courseDescriptionEdt;
  
    // creating a strings for storing our values from Edittext fields.
    private String courseName, courseDuration, courseDescription;
  
    // creating a variable for firebasefirestore.
    private FirebaseFirestore db;
  
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_update_course);
        Courses courses = (Courses) getIntent().getSerializableExtra("course");
  
        // getting our instance from Firebase Firestore.
        db = FirebaseFirestore.getInstance();
  
        // initializing our edittext and buttons
        courseNameEdt = findViewById(R.id.idEdtCourseName);
        courseDescriptionEdt = findViewById(R.id.idEdtCourseDescription);
        courseDurationEdt = findViewById(R.id.idEdtCourseDuration);
  
        // creating variable for button
        Button updateCOurseBtn = findViewById(R.id.idBtnUpdateCourse);
  
        courseNameEdt.setText(courses.getCourseName());
        courseDescriptionEdt.setText(courses.getCourseDescription());
        courseDurationEdt.setText(courses.getCourseDuration());
  
  
        updateCOurseBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                courseName = courseNameEdt.getText().toString();
                courseDescription = courseDescriptionEdt.getText().toString();
                courseDuration = courseDurationEdt.getText().toString();
  
                // validating the text fields if empty or not.
                if (TextUtils.isEmpty(courseName)) {
                    courseNameEdt.setError("Please enter Course Name");
                } else if (TextUtils.isEmpty(courseDescription)) {
                    courseDescriptionEdt.setError("Please enter Course Description");
                } else if (TextUtils.isEmpty(courseDuration)) {
                    courseDurationEdt.setError("Please enter Course Duration");
                } else {
                    // calling a method to update our course.
                    // we are passing our object class, course name,
                    // course description and course duration from our edittext field.
                    updateCourses(courses, courseName, courseDescription, courseDuration);
                }
            }
        });
    }
  
    private void updateCourses(Courses courses, String courseName, String courseDescription, String courseDuration) {
        // inside this method we are passing our updated values
        // inside our object class and later on we
        // will pass our whole object to firebase Firestore.
        Courses updatedCourse = new Courses(courseName, courseDescription, courseDuration);
  
        // after passing data to object class we are
        // sending it to firebase with specific document id.
        // below line is use to get the collection of our Firebase Firestore.
        db.collection("Courses").
                // below line is use toset the id of
                // document where we have to perform
                // update operation.
                document(courses.getId()).
  
                // after setting our document id we are
                // passing our whole object class to it.
                set(updatedCourse).
  
                // after passing our object class we are
                // calling a method for on success listener.
                addOnSuccessListener(new OnSuccessListener<Void>() {
                    @Override
                    public void onSuccess(Void aVoid) {
                        // on successful completion of this process
                        // we are displaying the toast message.
                        Toast.makeText(UpdateCourse.this, "Course has been updated..", Toast.LENGTH_SHORT).show();
                    }
                }).addOnFailureListener(new OnFailureListener() {
            // inside on failure method we are
            // displaying a failure message.
            @Override
            public void onFailure(@NonNull Exception e) {
                Toast.makeText(UpdateCourse.this, "Fail to update the data..", Toast.LENGTH_SHORT).show();
            }
        });
    }
}

Producción: