Open app or go to the google play store market in Android with Kotlin

blog-post.kt

// 앱이 설치 설치되었는지 판단하는 함수
fun Context.isInstalledApp(packageName: String): Boolean {
    val intent = packageManager.getLaunchIntentForPackage(packageName)
    return intent != null 
}

// 특정 앱을 실행하는 함수
fun Context.openApp(packageName: String) {
    val intent = packageManager.getLaunchIntentForPackage(packageName)
    startActivity(intent)
}

// 마켓으로 이동하는 함수
fun Context.market(packageName: String): Boolean {
    return try {
        val intent = Intent(Intent.ACTION_VIEW)
        intent.data = Uri.parse("market://details?id=$packageName")
        startActivity(intent)
        true
    } catch (e: ActivityNotFoundException) {
        e.printStackTrace()
        false
    }
}

// Usage
class ExampleActivity: AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        openAppOrGotoMarket() 
    }
  
    private fun openAppOrGotoMarket() {
        if (isInstalledApp(PACKAGE_NAME)) { // 내가 실행하고자 하는 앱이 있는가?
            openApp(PACKAGE_NAME)
            return
        }
        market(PACKAGE_NAME) // 없으면 마켓으로 보낸다.
    }
            
    companion object {
        private const val PACKAGE_NAME = "com.soulduse.app.example"
    }
}