[Android] 리소스 파일에 지정된 Navigation Safe Args 값을 기본값으로 리소스 파일에 전달

최근에는 안드로이드 제팩Navigation을 사용했지만 프래그먼트 간 화면 이동이 간단하게 이뤄질 수 있다고 느꼈다.
하지만 푹 빠진 부분도 있어서 메모로 남겨뒀어요.

Safe Args에서 리소스 파일에 지정된 값을 기본값으로 사용하고자 합니다.

Safe Args는 네비게이션과 데이터가 교차할 때 금형의 안전성을 확보할 수 있는 구조를 말한다.strings.xml에 정의된 문자열은 기본값으로 전송됩니다.
strings.xml

<string name="message">テストメッセージ</string>

예를 들어 세션의 레이아웃과 네비게이션 도표는 각각 다음과 같다.
각 코드의 설명은 여기에 있지 않다.
Navigation에 대한 설명 아래 기사 등은 쉽게 알 수 있다.

10분 분량의 Navigation 화면 마이그레이션 - Qiita

[Android] Navigation에서 매개변수가 있는 화면 마이그레이션을 위해 SafeArgs 사용 - Qiita

FirstFragment.kt

class FirstFragment : Fragment() {

    override fun onCreateView(
        inflater: LayoutInflater, container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {
        val view = inflater.inflate(R.layout.fragment_first, container, false)
        view.button.setOnClickListener {
            val action = FirstFragmentDirections.actionFirstFragmentToSecondFragment()
            it.findNavController().navigate(action)
        }
        return view
    }
}

fragment_first.xml

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout 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"
    tools:context=".view.FirstFragment">

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/button"
        android:id="@+id/button"/>

</FrameLayout>

SecondFragment.kt

class SecondFragment : Fragment() {
    private val args: SecondFragmentArgs by navArgs()

    override fun onCreateView(
        inflater: LayoutInflater, container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {
        val view = inflater.inflate(R.layout.fragment_second, container, false)
        view.text_view.text = args.message
        return view
    }
}

fragment_second.xml

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout 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"
    tools:context=".view.SecondFragment">

    <TextView
        android:id="@+id/text_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</FrameLayout>

nav_graph.xml

<?xml version="1.0" encoding="utf-8"?>
<navigation 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:id="@+id/nav_graph"
    app:startDestination="@id/firstFragment">

    <fragment
        android:id="@+id/firstFragment"
        android:name="com.example.view.FirstFragment"
        android:label="fragment_first"
        tools:layout="@layout/fragment_first">
        <action
            android:id="@+id/action_firstFragment_to_secondFragment"
            app:destination="@id/secondFragment" />
    </fragment>
    <fragment
        android:id="@+id/secondFragment"
        android:name="com.example.view.SecondFragment"
        android:label="fragment_second"
        tools:layout="@layout/fragment_second">
        <argument
            android:name="message"
            android:defaultValue="@string/message"
            app:argType="string" />
    </fragment>
</navigation>

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.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=".MainActivity">

    <androidx.fragment.app.FragmentContainerView
        android:id="@+id/nav_host_fragment"
        android:name="androidx.navigation.fragment.NavHostFragment"
        android:layout_width="0dp"
        android:layout_height="0dp"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintBottom_toBottomOf="parent"
        app:defaultNavHost="true"
        app:navGraph="@navigation/nav_graph" />

</androidx.constraintlayout.widget.ConstraintLayout>

그러나 프로그램이 시작될 때 다음 로그를 출력하고 충돌합니다.

2020-11-11 22:14:44.768 9509-9509/com.example E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.example, PID: 9509
    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example/com.example.MainActivity}: android.view.InflateException: Binary XML file line #14 in com.example:layout/activity_main: Binary XML file line #14 in com.example:layout/activity_main: Error inflating class androidx.fragment.app.FragmentContainerView
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3270)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3409)
        at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:83)
        at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2016)
        at android.os.Handler.dispatchMessage(Handler.java:107)
        at android.os.Looper.loop(Looper.java:214)
        at android.app.ActivityThread.main(ActivityThread.java:7356)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930)
     Caused by: android.view.InflateException: Binary XML file line #14 in com.example:layout/activity_main: Binary XML file line #14 in com.example:layout/activity_main: Error inflating class androidx.fragment.app.FragmentContainerView
     Caused by: android.view.InflateException: Binary XML file line #14 in com.example:layout/activity_main: Error inflating class androidx.fragment.app.FragmentContainerView
     Caused by: java.lang.RuntimeException: Exception inflating com.example:navigation/nav_graph line 22
        at androidx.navigation.NavInflater.inflate(NavInflater.java:90)
        at androidx.navigation.NavController.setGraph(NavController.java:499)
        at androidx.navigation.NavController.setGraph(NavController.java:481)
        at androidx.navigation.fragment.NavHostFragment.onCreate(NavHostFragment.java:237)
        at androidx.fragment.app.Fragment.performCreate(Fragment.java:2685)
        at androidx.fragment.app.FragmentStateManager.create(FragmentStateManager.java:280)
        at androidx.fragment.app.FragmentManager.moveToState(FragmentManager.java:1187)
        at androidx.fragment.app.FragmentManager.addAddedFragments(FragmentManager.java:2236)
        at androidx.fragment.app.FragmentManager.executeOpsTogether(FragmentManager.java:2009)
        at androidx.fragment.app.FragmentManager.removeRedundantOperationsAndExecute(FragmentManager.java:1965)
        at androidx.fragment.app.FragmentManager.execSingleAction(FragmentManager.java:1830)
        at androidx.fragment.app.BackStackRecord.commitNowAllowingStateLoss(BackStackRecord.java:303)
        at androidx.fragment.app.FragmentContainerView.<init>(FragmentContainerView.java:166)
        at androidx.fragment.app.FragmentLayoutInflaterFactory.onCreateView(FragmentLayoutInflaterFactory.java:51)
        at androidx.fragment.app.FragmentController.onCreateView(FragmentController.java:135)
        at androidx.fragment.app.FragmentActivity.dispatchFragmentsOnCreateView(FragmentActivity.java:356)
        at androidx.fragment.app.FragmentActivity.onCreateView(FragmentActivity.java:335)
        at android.view.LayoutInflater.tryCreateView(LayoutInflater.java:1069)
        at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:997)
        at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:961)
        at android.view.LayoutInflater.rInflate(LayoutInflater.java:1123)
        at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:1084)
        at android.view.LayoutInflater.inflate(LayoutInflater.java:682)
        at android.view.LayoutInflater.inflate(LayoutInflater.java:534)
        at android.view.LayoutInflater.inflate(LayoutInflater.java:481)
        at androidx.appcompat.app.AppCompatDelegateImpl.setContentView(AppCompatDelegateImpl.java:696)
2020-11-11 22:14:44.771 9509-9509/com.example E/AndroidRuntime:     at androidx.appcompat.app.AppCompatActivity.setContentView(AppCompatActivity.java:170)
        at com.example.MainActivity.onCreate(MainActivity.kt:13)
        at android.app.Activity.performCreate(Activity.java:7802)
        at android.app.Activity.performCreate(Activity.java:7791)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1299)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3245)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3409)
        at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:83)
        at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2016)
        at android.os.Handler.dispatchMessage(Handler.java:107)
        at android.os.Looper.loop(Looper.java:214)
        at android.app.ActivityThread.main(ActivityThread.java:7356)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930)
     Caused by: org.xmlpull.v1.XmlPullParserException: unsupported value 'テストメッセージ' for string. You must use a "reference" type to reference other resources.
        at androidx.navigation.NavInflater.inflateArgument(NavInflater.java:206)
        at androidx.navigation.NavInflater.inflateArgumentForDestination(NavInflater.java:146)
        at androidx.navigation.NavInflater.inflate(NavInflater.java:121)
        at androidx.navigation.NavInflater.inflate(NavInflater.java:132)
        at androidx.navigation.NavInflater.inflate(NavInflater.java:81)
        	... 42 more

까닭

app:argType="string"에 비해 데이터 유형이 일치하지 않기 때문이다.

Caused by: org.xmlpull.v1.XmlPullParserException: unsupported value 'テストメッセージ' for string. You must use a "reference" type to reference other resources.

는 언뜻 보기에는 괜찮은 것 같지만android:defaultValue="@string/message"String 자체가 아니라 자원 ID(int)여서 데이터 유형이 다르다고 여겨진다.

해결책

@string/message의nav_graph.xml를 app:argType로 변경한다.
nav_graph.xml

...
<argument
    android:name="message"
    android:defaultValue="@string/message"
    app:argType="reference" />
...

이렇게 되면 발송 자원 ID로 변경되기 때문에 다음과 같이 변경됩니다reference.
SecondFragment.kt

...
view.text_view.text = getString(args.message)
...

이렇게 하면 시작할 때 붕괴되지 않고 정상적으로 운행할 수 있다.