Accessing a deep link intent's data / URL in a fragment with AndroidX

Usually, accessing the data associated with a deep link intent in an Activity is just a case of calling intent.data. Easy!

However when this intent is forwarded to a fragment (using the AndroidX navigation code below), the intent suddenly becomes much harder to deal with. In the fragment there is no onNewIntent, or even any intent at all. This tutorial will cover how to retrieve the intent’s data, including deep link URL.

override fun onNewIntent(intent: Intent?) {
    super.onNewIntent(intent)
    my_nav_host_fragment.findNavController().onHandleDeepLink(intent)
}

When the intent was forwarded to the fragment, it was significantly changed. It has now been packaged into arguments, which contains an ArrayMap called mMap, as well as a few other properties.

If you want to access this ArrayMap (for example to access the URL in the deep link), you can just call arguments?.get(yourKey). However, what if you don’t know the key, since there’s no obvious way of looking it up?

In that case you need to call arguments?.keySet(), to receive an array of the keys the main ArrayMap uses. For example, my intent only had the deep link intent as a key:

Now that you’ve got your key, you can call arguments?.get(yourKey) as Intent, to get your original intent back! This intent can then be queried as usual, such as .data.encodedPath to get the URL’s path.

Here’s a useful function that can be called in a fragment to determine if the current arguments are from a deep link for your target path:

fun isTargetPath(): Boolean {
    val deepLinkKey = arguments?.keySet()?.firstOrNull() ?: ""
    if (deepLinkKey.isNotEmpty() && arguments?.get(deepLinkKey) is Intent) {
        val targetPath = "/mytargetpath"
        return (arguments?.get(deepLinkKey) as Intent).data.encodedPath == targetPath
    }
    return false
}

This should go in your onViewCreated, to avoid it being called repeatedly if the use pauses / resumes your fragment.