How can I display within FirebaseUi RecyclerView?

Question

I am unable to display any item on my Recyclerview. I sure my DB connection is fine.

But finally, it can't anything in the RecyclerView, I don't know what happens, since i touch android studio just 2 weeks.

This is my database structure

Root
  |
  |__restaurant
       |_____name
               |_____1
                     |_____lat: "22.34554"
                     |_____long: "34.124253"
                     |_____name: "A"
               |_____2
                     |_____lat: "24.34554"
                     |_____long: "35.124253"
                     |_____name: "B"

I want to show all restaurant name like A, B

This is my activity (nearActivity.java)

    package com.example.chanyuenpan.garretproject3;

    import android.arch.lifecycle.LifecycleObserver;
    import android.support.annotation.NonNull;
    import android.support.v7.app.AppCompatActivity;
    import android.os.Bundle;
    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.TextView;

    import com.firebase.ui.database.FirebaseRecyclerAdapter;
    import com.firebase.ui.database.FirebaseRecyclerOptions;
    import com.firebase.ui.database.ObservableSnapshotArray;
    import com.google.firebase.database.DatabaseReference;
    import com.google.firebase.database.FirebaseDatabase;
    import com.google.firebase.database.Query;

        public class nearActivity extends AppCompatActivity {

        private restaurant restaurant;
        private DatabaseReference myRef;
        private RecyclerView recyclerView;
        private static final String TAG = "FirebaseRecyclerAdapter";

        Query query = FirebaseDatabase.getInstance()
                .getReference()
                .child("chats")
                .limitToLast(50);


        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_near);

            myRef = FirebaseDatabase.getInstance().getReference().child("Restaurant");
            myRef.keepSynced(true);

            recyclerView = (RecyclerView) findViewById(R.id.my_RevlerView);
            recyclerView.setLayoutManager(new LinearLayoutManager(this));
            final FirebaseDatabase database = FirebaseDatabase.getInstance();





            FirebaseRecyclerOptions<restaurant> options =
                    new FirebaseRecyclerOptions.Builder<restaurant>()
                            .setQuery(myRef, restaurant.class)
                            .build();

            FirebaseRecyclerAdapter<restaurant, myViewHolder> adapter = 
new FirebaseRecyclerAdapter<restaurant, myViewHolder>(options) {
                @Override
                protected void onBindViewHolder(@NonNull myViewHolder holder, int position, @NonNull restaurant model) {

                        holder.myTextView.setText(model.getName());
                }

                @Override
                public myViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
                    View view = LayoutInflater.from(parent.getContext())
                            .inflate(R.layout.activity_near, parent, false);

                    return new nearActivity.myViewHolder(view);
                }
            };

            recyclerView.setAdapter(adapter);




        }



        public static class myViewHolder extends RecyclerView.ViewHolder{

            public TextView myTextView;

            public myViewHolder(View itemView){
                super(itemView);

                myTextView = itemView.findViewById(android.R.id.text1);

            }
        }    
    }

This is my xml (activity_near.xml)

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.example.chanyuenpan.garretproject3.nearActivity">

    <android.support.v7.widget.RecyclerView
        android:id="@+id/my_RevlerView"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />
</android.support.constraint.ConstraintLayout>

This is my restaurant.java (Class)

package com.example.chanyuenpan.garretproject3;

import java.io.Serializable;

    public class restaurant implements Serializable {

        String mlat;
        String mlogi;
        String mname;

        public restaurant(){}

        public restaurant (String lat, String logi, String name){
            mlat = lat;
            mlogi = logi;
            mname = name;
        }

        public String getlat() {
            return mlat;
        }

        public void setLong(String logi) { mlogi = logi; }

        public String getlogi(){
            return mlogi;
        }

        public void setLat(String lat) { mlat = lat; }

        public String getName(){
            return mname;
        }
        public void setName(String name) { mname = name; }
    }

This is my build.gradle

    apply plugin: 'com.android.application'

android {
    compileSdkVersion 26
    defaultConfig {
        applicationId "com.example.chanyuenpan.garretproject3"
        minSdkVersion 25
        targetSdkVersion 26
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'com.android.support:appcompat-v7:26.1.0'
    implementation 'com.android.support.constraint:constraint-layout:1.0.2'
    implementation 'com.google.android.gms:play-services-maps:11.8.0'
    implementation 'com.google.android.gms:play-services-location:11.8.0'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.1'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.1'
    compile 'com.google.firebase:firebase-core:11.8.0'
    compile 'com.google.firebase:firebase-database:11.8.0'
    compile 'com.google.firebase:firebase-storage:11.8.0'
    compile 'com.google.firebase:firebase-auth:11.8.0'
    compile 'com.android.support:cardview-v7:26.1.0'
    compile 'com.android.support:recyclerview-v7:26.1.0'
    compile 'com.firebaseui:firebase-ui-database:3.2.2'
    compile 'com.firebaseui:firebase-ui:3.2.2'
    compile 'com.firebaseui:firebase-ui-auth:3.2.2'
    implementation 'com.firebaseui:firebase-ui-storage:3.2.2'
    implementation 'com.firebaseui:firebase-ui-firestore:3.2.2'





    implementation 'com.android.support:design:26.1.0'
}

apply plugin: 'com.google.gms.google-services'

did you used mAdapter.startListening() in your onStart() method ? — Gastón Saillén, Mar 19 '18 at 19:50
um... I have not create the onStart() method, I bulit all Recyclerview in OnCreate, Do i need to build a OnStart() method? — Chan Yuen Pan, Mar 19 '18 at 20:01

score 0 · Answer 1 · answered Mar 20 '18 at 00:14

There are a few things wrong:

Your data class should use consistent getters and setters (so getlogi should be getLong) and have private fields. (Also, getlat should be getLat. The setters look good.)
The query you pass into the recycler options builder is incorrect: it should be FirebaseDatabase.getInstance().getReference().child("restaurant").child("name").limitToLast(50);. I'd recommend getting rid of the unnecessary name folder too.
All the other references to the Firebase Database should be removed since they aren't capitalized correctly and won't help populate the recyclerview.
The FirebaseRecyclerOptions builder should include a call to setLifecycleOwner(this).

How can I display within FirebaseUi RecyclerView?

1 Answers1