How can I use an API to implement a search functionality on Android?

Question

I am attempting to create a search functionality in an android application and have been doing research on how I can accomplish this while taking in data from a third party API. I am still learning much about the android environment, so I could use some guidance on how I can go about completing this task. Say for example, I have an API https://www.example.com/api/json/15504877/search with an API key of 15504877, how would I use this link & key so that it pulls the data from this API in my android app upon a user searching for something like pet breed (for example)? Any information would help, I have a base activity and would like to complete this within it and also have some code below and I will add more information if necessary.

MainActivity.kt:

package com.example.application

import android.os.Bundle
import com.google.android.material.bottomnavigation.BottomNavigationView
import androidx.appcompat.app.AppCompatActivity
import androidx.navigation.findNavController
import androidx.navigation.ui.AppBarConfiguration
import androidx.navigation.ui.setupActionBarWithNavController
import androidx.navigation.ui.setupWithNavController
import com.example.application.databinding.ActivityMainBinding

class MainActivity : AppCompatActivity() {

    private lateinit var binding: ActivityMainBinding

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        binding = ActivityMainBinding.inflate(layoutInflater)
        setContentView(binding.root)

        val navView: BottomNavigationView = binding.navView

        val navController = findNavController(R.id.nav_host_fragment_activity_main)
        // Passing each menu ID as a set of Ids because each
        // menu should be considered as top level destinations.
        val appBarConfiguration = AppBarConfiguration(
            setOf(
                R.id.navigation_home, R.id.navigation_dashboard, R.id.navigation_notifications
            )
        )
        setupActionBarWithNavController(navController, appBarConfiguration)
        navView.setupWithNavController(navController)
    }
}

HomeViewModel.kt:

package com.example.application.ui.home

import androidx.lifecycle.LiveData
import androidx.lifecycle.MutableLiveData
import androidx.lifecycle.ViewModel

class HomeViewModel : ViewModel() {

    private val _text = MutableLiveData<String>().apply {
        value = "This is home Fragment"
    }
    val text: LiveData<String> = _text
}

HomeFragment.kt:

package com.example.application.ui.home

import android.os.Bundle
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.TextView
import androidx.fragment.app.Fragment
import androidx.lifecycle.ViewModelProvider
import com.example.application.databinding.FragmentHomeBinding

class HomeFragment : Fragment() {

    private var _binding: FragmentHomeBinding? = null

    // This property is only valid between onCreateView and
    // onDestroyView.
    private val binding get() = _binding!!

    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View {
        val homeViewModel =
            ViewModelProvider(this).get(HomeViewModel::class.java)

        _binding = FragmentHomeBinding.inflate(inflater, container, false)
        val root: View = binding.root

        val textView: TextView = binding.textHome
        homeViewModel.text.observe(viewLifecycleOwner) {
            textView.text = it
        }
        return root
    }

    override fun onDestroyView() {
        super.onDestroyView()
        _binding = null
    }
}

AndroidManifest.xml:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.application">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.Application">
        <activity
            android:name=".MainActivity"
            android:exported="true"
            android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

Answer 1

For an http request to api, you need to use a third-party library. For example, OkHttp, or, which is recommended, Retrofit (essentially a wrapper over OkHttp). There is a lot of lessons all over the Internet on how to use this library, for example, here. On my own behalf, I would like to add that if you want to follow the mvvm-architecture, you must take out the logic for obtaining data in a separate object (which usually called a repository), and then you need to call method of the repository inside the ViewModel to put the data in LiveData