A NavHostFragment
is a component available in Android Jetpack and is primarily responsible for providing "an area in your layout for self-contained navigation to occur."
The Turbo extension of this class, TurboSessionNavHostFragment
, along with being responsible for self-contained TurboFragment
navigation, also manages a TurboSesssion
and a TurboWebView
instance. You will need to implement a few things for this abstract class:
- The name of the
TurboSession
(this is arbitrary, but must be unique in your app) - The url of a starting location when your app starts up. Note: if you're running your app locally without HTTPS, you'll need to adjust your
android:usesCleartextTraffic
settings in the AndroidManifest.xml (or use an Android Network security configuration), and target10.0.2.2
instead oflocalhost
. - A list of registered activities that Turbo will be able to navigate to (optional)
- A list of registered fragments that Turbo will be able to navigate to
- The location of your
TurboPathConfiguration
JSON file(s) to configure navigation rules
In its simplest form, the implementation of your TurboSessionNavHostFragment
will look like:
MainSessionNavHostFragment
:
import dev.hotwire.turbo.session.TurboSessionNavHostFragment
class MainSessionNavHostFragment : TurboSessionNavHostFragment() {
override val sessionName = "main"
override val startLocation = "https://turbo-native-demo.glitch.me/"
override val registeredActivities: List<KClass<out AppCompatActivity>>
get() = listOf(
// Leave empty unless you have more
// than one TurboActivity in your app
)
override val registeredFragments: List<KClass<out Fragment>>
get() = listOf(
WebFragment::class
// And any other TurboFragments in your app
)
override val pathConfigurationLocation: TurboPathConfiguration.Location
get() = TurboPathConfiguration.Location(
assetFilePath = "json/configuration.json",
remoteFileUrl = "https://turbo.hotwired.dev/demo/configurations/android-v1.json"
)
}
See the Fragment section below to create a TurboFragment
that you'll register here. See the Path Configuration documentation to create your path configuration file(s).
Refer to the demo MainSessionNavHostFragment
for an example.
It's strongly recommended to use a single-Activity architecture in your app. Generally, you'll have one TurboActivity
and many TurboFragments
.
You need to create a layout resource file that your TurboActivity
will use to host the TurboSessionNavHostFragment
that you created above.
Android Jetpack provides a FragmentContainerView
to contain NavHostFragment
navigation. In its simplest form, your Activity layout file will look like:
res/layout/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"
android:layout_width="match_parent"
android:layout_height="match_parent">
<androidx.fragment.app.FragmentContainerView
android:id="@+id/main_nav_host"
android:name="dev.hotwire.turbo.demo.main.MainSessionNavHostFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:defaultNavHost="false" />
</androidx.constraintlayout.widget.ConstraintLayout>
Refer to the demo activity_main.xml
for an example.
A Turbo Activity is straightforward and needs to implement the TurboActivity
interface in order to provide a TurboActivityDelegate
.
Your Activity should extend Android Jetpack's AppCompatActivity
. In its simplest form, your Activity will look like:
MainActivity.kt
:
class MainActivity : AppCompatActivity(), TurboActivity {
override lateinit var delegate: TurboActivityDelegate
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
delegate = TurboActivityDelegate(this, R.id.main_nav_host)
}
}
Note that R.layout.activity_main
refers to the Activity layout file that you already created. R.id.main_nav_host
refers to the MainSessionNavHostFragment
that you created, hosted in the layout file.
Refer to the demo MainActivity
as an example. (Don't forget to add your Activity to your app's AndroidManifest.xml
file.)
You'll need at least one web Fragment that will serve as a destination for urls that display web content in your app.
A web Fragment is straightforward and needs to implement the TurboWebFragment
abstract class. This abstract class implements the TurboWebFragmentCallback
interface, which provides a number of functions available to customize your Fragment.
You'll need to annotate each Fragment in your app with a @TurboNavGraphDestination
annotation with a URI of your own scheme. This URI is used by the library to build an internal navigation graph and map url path patterns to the destination Fragment with the corresponding URI. See the Path Configuration documentation to learn how to map url paths to destination Fragments.
In its simplest form, your web Fragment will look like:
WebFragment.kt
:
@TurboNavGraphDestination(uri = "turbo://fragment/web")
class WebFragment : TurboWebFragment()
The library automatically inflates a default R.layout.turbo_fragment_web
layout to host a TurboView
. If you'd like to create your own custom layout for your web Fragment, you can override the onCreateView()
function and inflate your own layout. See the demo WebHomeFragment
as an example of of providing your own layout.
You can also provide your own custom progress view or error view by overriding the createProgressView()
and createErrorView()
functions in your web Fragment.
Refer to demo WebFragment
as an example.
See the documentation to learn about setting up your path configuration
See the documenation to learn about navigating between destinations.
See the documentation to learn about the advanced options available.