Setting an Array that belongs to a fragment from the main activity

Question

EDIT 2: Fragment Adapter:

public class PageAdapter extends FragmentStatePagerAdapter {
    ArrayList<Song> songList; //Update
    public PageAdapter(FragmentManager fm) {
        super(fm);
    }

    @Override
    public Fragment getItem(int i) {
        switch (i) {
            case 0:
                return MusicList.newInstance(songList); //Update
        }
        return null;
    }

    @Override
    public int getCount() {
        return 1; //No of Tabs
    }
}

EDIT: id.music_list_fragment(layout.fragment_main) Layout:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/music_list_fragment"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical"
android:background="@drawable/headphones">

    <ListView
        android:id="@+id/song_list"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:clickable="true">
    </ListView>

</LinearLayout>

I'm trying to send an Array list from the activity "MainActivity" to its fragment "MusicList" by replacing the fragment.

By using this in the activity:

    FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
    Fragment fragment = MusicList.newInstance(songList);
    ft.replace(R.id.music_list_fragment, fragment);
    ft.commit();

And using this in the fragment:

public static MusicList newInstance(ArrayList<Song> songList) {
    MusicList fragment = new MusicList();
    Bundle bundle = new Bundle();
    bundle.putSerializable(DESCRIBABLE_KEY, songList);
    fragment.setArguments(bundle);

    return fragment;
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    View v = inflater.inflate(R.layout.fragment_main, container, false);
    mList = ((ListView)v.findViewById(R.id.song_list));
    msongList = (ArrayList<Song>) getArguments().getSerializable(DESCRIBABLE_KEY);
    SongAdapter sAdapter = new SongAdapter(getActivity(), msongList);
    mList.setAdapter(sAdapter);

    return v;
}

And I'm getting this error:

java.lang.RuntimeException: Unable to start activity ComponentInfo{pal.mplayercomeon/pal.mplayercomeon.MainActivity}: java.lang.IllegalArgumentException: No view found for id 0x7f0c0074 (pal.mplayercomeon:id/music_list_fragment) for fragment MusicList{ee972d3 #0 id=0x7f0c0074}
                                                                       at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2646)
                                                                       at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2707)
                                                                       at android.app.ActivityThread.-wrap12(ActivityThread.java)
                                                                       at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1460)
                                                                       at android.os.Handler.dispatchMessage(Handler.java:102)
                                                                       at android.os.Looper.loop(Looper.java:154)
                                                                       at android.app.ActivityThread.main(ActivityThread.java:6077)
                                                                       at java.lang.reflect.Method.invoke(Native Method)
                                                                       at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865)
                                                                       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)
                                                                    Caused by: java.lang.IllegalArgumentException: No view found for id 0x7f0c0074 (pal.mplayercomeon:id/music_list_fragment) for fragment MusicList{ee972d3 #0 id=0x7f0c0074}
                                                                       at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1059)
                                                                       at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1252)
                                                                       at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:742)
                                                                       at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1617)
                                                                       at android.support.v4.app.FragmentController.execPendingActions(FragmentController.java:339)
                                                                       at android.support.v4.app.FragmentActivity.onStart(FragmentActivity.java:601)
                                                                       at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1248)
                                                                       at android.app.Activity.performStart(Activity.java:6681)
                                                                       at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2609)
                                                                       at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2707) 
                                                                       at android.app.ActivityThread.-wrap12(ActivityThread.java) 
                                                                       at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1460) 
                                                                       at android.os.Handler.dispatchMessage(Handler.java:102) 
                                                                       at android.os.Looper.loop(Looper.java:154) 
                                                                       at android.app.ActivityThread.main(ActivityThread.java:6077) 
                                                                       at java.lang.reflect.Method.invoke(Native Method) 
                                                                       at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865) 
                                                                       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755) 

Answer 1

1. You need to initialize an ArrayList before you pass to the Fragment newInstance method, otherwise it is null.
2. You are using a PagerAdapter, so you add that to a ViewPager. You do not need a FragmentTransaction, so that code is irrelevant. The getCount method of the adapter loads that many Fragments in the ViewPager.
3. Follow-up on 2, this is not right ... ft.replace(R.id.music_list_fragment, fragment);, unless android:id="@+id/music_list_fragment" is contained as a FrameLayout inside of the Activity XML, not the Fragment XML. But, as stated, you seem to want to use a ViewPager

Additional point - Song needs to implement Serializable, however, you really should be using Parcelable because that is the preferred way to pass data in Android.

Answer 2

You trying to replace the view inside you fragment from the activity by calling the fragment's linearlayout view id from the activity. You need to add <FrameLayout> to your activity xml

<FrameLayout android:id="@+id/fragment_placeholder" 
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

This will hold the place for you fragment until you'll call:

ft.replace(R.id.fragment_placeholder, fragment);