How to search users from database using retrofit in Android studio? SOLVED

Question

Edit: I have found a solution. I have made a search function in Laravel, which was a simple query, then implemented in Android Studio an edittext onquerylistener in which I have called the function from the laravel. And it works perfectly.

I need to implement an invitation function in my Android application but I have no prior knowledge for this. The idea is that I have an Edittext (or maybe another field) where the user can search for other users, who are registered, and by clicking on them they appear below the search field in a listview. And by clicking on the invite button everyone in the listview gets a notification/invitation. How can this be done using retrofit? It should be something like for each character written an API request is sent and suggestions are shown. I am using Laravel and Android(java). I don't have much code written here because I don't know where and how to start. Here is the request:

 @GET("users")
 Call<List<User>> getUsers(@Header("Authorization") String token);

Here is the getUsers method so far in the activity:

  private void getUsers(){
    Log.d(TAG, "onResponse: loadData called");
    ApiService service = RetrofitBuilder.getRetrofitInstance().create(ApiService.class);
    Call<List<User>> call = service.getUsers("Bearer "+token);
    call.enqueue(new Callback<List<User>>() {
        @Override
        public void onResponse(@NonNull Call<List<User>> call, @NonNull Response<List<User>> response) {
            try {
                if (response.isSuccessful()){
                    Log.d(TAG, "onResponse: successful loadData called");

                    adapter = new UserAdapter(mContext, arrayList);
                    listView.setAdapter(adapter);
                }
                else{
                    Log.d(TAG, "onResponse: " + response.body());
                }
            }
            catch (Exception e){
                Toast.makeText(TeamAdminActivity.this, e.getMessage(), Toast.LENGTH_LONG).show();
            }
        }

        @Override
        public void onFailure(@NonNull Call<List<User>> call, @NonNull Throwable t) {
            Log.d("Response", "onFailure: " + t.toString());
        }
    });
}

Also a snippet of my xml file:

 <TextView
            android:id="@+id/invite"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginStart="@dimen/activity_vertical_margin"
            android:layout_marginTop="36dp"
            android:layout_below="@id/team_title"
            android:textSize="24sp"
            android:textColor="@color/colorPrimary"
            android:text="@string/invite_members" />

        <com.google.android.material.textfield.TextInputLayout
            android:id="@+id/search"
            style="@style/TextInputLayoutAppearance"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_below="@id/invite"
            android:layout_marginTop="10dp"
            android:layout_marginStart="18dp"
            android:layout_marginEnd="18dp"
            android:hint="@string/search"
            android:textSize="23sp"
            app:boxStrokeColor="@color/colorPrimaryDark">

            <com.google.android.material.textfield.TextInputEditText
                android:id="@+id/search_et"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_below="@+id/spinner"
                android:hint="@string/event_name"
                android:textSize="18sp" />
        </com.google.android.material.textfield.TextInputLayout>
        <Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_below="@id/invite"
            android:layout_toEndOf="@+id/search"/>

        <TextView
            android:id="@+id/invited"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginStart="@dimen/activity_vertical_margin"
            android:layout_marginTop="36dp"
            android:layout_below="@id/search"
            android:textSize="24sp"
            android:textColor="@color/colorPrimary"
            android:text="@string/invited" />

        <androidx.core.widget.NestedScrollView
            android:id="@+id/scroll_view"
            android:layout_width="match_parent"
            android:layout_height="150dp"
            android:layout_below="@id/invited">

            <ListView
                android:layout_width="match_parent"
                android:layout_height="wrap_content" />

        </androidx.core.widget.NestedScrollView>

        <Button
            android:id="@+id/create_team_btn"
            android:layout_width="260dp"
            android:layout_height="60dp"
            android:layout_below="@+id/scroll_view"
            android:layout_centerHorizontal="true"
            android:layout_marginTop="18dp"
            android:layout_marginBottom="14dp"
            android:background="@drawable/my_color_button"
            android:text="@string/invite"
            android:textColor="@color/myWhite" />

Answer 1

arrayList ? did you add the response's body into the list when the response is successful ? or just pass the response's body into the adapter Like

adapter = new UserAdapter(mContext, response.body());

Answer 2

You can do this by implementing Observer in your activity or fragment where you want to add invitation functionality.

Create class which extends Observable:

public class FilterManager extends Observable {
    private String query;

    public String getQuery() {
        return query;
    }

    public void setQuery(String query) {
        this.query = query;
        setChanged();
        notifyObservers();
    }

}

Suppose you have Fragment for the invitation:

public class InvitationFragment extends Fragment implements Observer
{
    //your other code here

    @Override
    public void update(Observable observable, Object o) {
        if(observable instanceof FilterManager){

           //retrieve the search value          
            String result = ((FilterManager)observable).getQuery();

            if(!result.isEmpty())
                getUsers(result); //call api getUsrs method here
            else {
                userList = null;
                setRecyclerView(getContext());
            }          
        }
    }

    private void getUsers(String query){
       //your code here
    }
}

Change your rest api call:

@GET("users/{query}")
Call<List<User>> getUsers(@Header("Authorization") String token,@Path("query") String query);