[android] Set selected item in Android BottomNavigationView

IF YOU NEED TO DYNAMICALLY PASS FRAGMENT ARGUMENTS DO THIS

There are plenty of (mostly repeated or outdated) answers here but none of them handles a very common need: dynamically passing different arguments to the Fragment loaded into a tab.

You can't dynamically pass different arguments to the loaded Fragment by using setSelectedItemId(R.id.second_tab), which ends up calling the static OnNavigationItemSelectedListener. To overcome this limitation I've ended up doing this in my MainActivity that contains the tabs:

fun loadArticleTab(articleId: String) {
    bottomNavigationView.menu.findItem(R.id.tab_article).isChecked = true // use setChecked() in Java
    supportFragmentManager
        .beginTransaction()
        .replace(R.id.main_fragment_container, ArticleFragment.newInstance(articleId))
        .commit()
}

The ArticleFragment.newInstance() method is implemented as usual:

private const val ARG_ARTICLE_ID = "ARG_ARTICLE_ID"

class ArticleFragment : Fragment() {

    companion object {
        /**
         * @return An [ArticleFragment] that shows the article with the given ID.
         */
        fun newInstance(articleId: String): ArticleFragment {
            val args = Bundle()
            args.putString(ARG_ARTICLE_ID, day)
            val fragment = ArticleFragment()
            fragment.arguments = args
            return fragment
        }
    }

}