Merge pull request #351 from hotwired/fix-same-page-restore

Backport the ability to fix same page restores from `hotwire-native-android`

Author: jayohms

turbo/src/main/assets/js/turbo_bridge.js

@@ -57,6 +57,22 @@
       }
     }
 
+    restoreCurrentVisit() {
+      // A synthetic "restore" visit to the currently rendered location can occur when
+      // visiting a web -> native -> back to web screen. In this situation, the connect()
+      // callback (from Stimulus) in bridge component controllers will not be called,
+      // since they are already connected. We need to notify the web bridge library
+      // that the webview has been reattached to manually trigger connect() and notify
+      // the native app so the native bridge component view state can be restored.
+      document.dispatchEvent(new Event("native:restore"))
+    }
+
+    cacheSnapshot() {
+      if (window.Turbo) {
+        Turbo.session.view.cacheSnapshot()
+      }
+    }
+
     // Current visit
 
     issueRequestForVisitWithIdentifier(identifier) {

turbo/src/main/kotlin/dev/hotwire/turbo/delegates/TurboWebFragmentDelegate.kt

@@ -18,6 +18,7 @@ import dev.hotwire.turbo.session.TurboSession
 import dev.hotwire.turbo.session.TurboSessionCallback
 import dev.hotwire.turbo.session.TurboSessionModalResult
 import dev.hotwire.turbo.util.dispatcherProvider
+import dev.hotwire.turbo.util.location
 import dev.hotwire.turbo.views.TurboView
 import dev.hotwire.turbo.views.TurboWebView
 import dev.hotwire.turbo.visit.TurboVisit
@@ -132,6 +133,24 @@ internal class TurboWebFragmentDelegate(
         }
     }
 
+    /**
+     * Should be called by the implementing Fragment during
+     * [androidx.fragment.app.Fragment.onDestroyView].
+     */
+    fun onDestroyView() {
+        // Manually cache a snapshot of the WebView when navigating from a
+        // web screen to a native screen. This allows a "restore" visit when
+        // revisiting this location again.
+
+        val navHost = navDestination.sessionNavHostFragment
+        val currentBackStackEntry = navHost.navController.currentBackStackEntry
+        val currentLocation = currentBackStackEntry?.location
+
+        if (session().currentVisit?.location != currentLocation) {
+            session().cacheSnapshot()
+        }
+    }
+
     /**
      * Should be called by the implementing Fragment during
      * [dev.hotwire.turbo.nav.TurboNavDestination.refresh]
@@ -323,8 +342,8 @@ internal class TurboWebFragmentDelegate(
             // Visit every time the WebView is reattached to the current Fragment.
             if (isWebViewAttachedToNewDestination) {
                 val currentSessionVisitRestored = !isInitialVisit &&
-                    session().currentVisit?.destinationIdentifier == identifier &&
-                    session().restoreCurrentVisit(this)
+                        session().currentVisit?.destinationIdentifier == identifier &&
+                        session().restoreCurrentVisit(this)
 
                 if (!currentSessionVisitRestored) {
                     showProgressView(location)

turbo/src/main/kotlin/dev/hotwire/turbo/fragments/TurboWebBottomSheetDialogFragment.kt

@@ -40,6 +40,11 @@ abstract class TurboWebBottomSheetDialogFragment : TurboBottomSheetDialogFragmen
         webDelegate.onViewCreated()
     }
 
+    override fun onDestroyView() {
+        super.onDestroyView()
+        webDelegate.onDestroyView()
+    }
+
     override fun activityResultLauncher(requestCode: Int): ActivityResultLauncher<Intent>? {
         return when (requestCode) {
             TURBO_REQUEST_CODE_FILES -> webDelegate.fileChooserResultLauncher

turbo/src/main/kotlin/dev/hotwire/turbo/fragments/TurboWebFragment.kt

@@ -9,11 +9,11 @@ import android.view.ViewGroup
 import androidx.activity.result.ActivityResultLauncher
 import dev.hotwire.turbo.R
 import dev.hotwire.turbo.delegates.TurboWebFragmentDelegate
+import dev.hotwire.turbo.errors.TurboVisitError
 import dev.hotwire.turbo.session.TurboSessionModalResult
 import dev.hotwire.turbo.util.TURBO_REQUEST_CODE_FILES
 import dev.hotwire.turbo.views.TurboView
 import dev.hotwire.turbo.views.TurboWebChromeClient
-import dev.hotwire.turbo.errors.TurboVisitError
 
 /**
  * The base class from which all web "standard" fragments (non-dialogs) in a
@@ -38,6 +38,11 @@ abstract class TurboWebFragment : TurboFragment(), TurboWebFragmentCallback {
         webDelegate.onViewCreated()
     }
 
+    override fun onDestroyView() {
+        super.onDestroyView()
+        webDelegate.onDestroyView()
+    }
+
     override fun onStart() {
         super.onStart()
 

turbo/src/main/kotlin/dev/hotwire/turbo/session/TurboSession.kt

@@ -5,7 +5,14 @@ import android.content.Context
 import android.graphics.Bitmap
 import android.net.http.SslError
 import android.util.SparseArray
-import android.webkit.*
+import android.webkit.HttpAuthHandler
+import android.webkit.JavascriptInterface
+import android.webkit.RenderProcessGoneDetail
+import android.webkit.SslErrorHandler
+import android.webkit.WebChromeClient
+import android.webkit.WebResourceRequest
+import android.webkit.WebResourceResponse
+import android.webkit.WebView
 import androidx.appcompat.app.AppCompatActivity
 import androidx.lifecycle.lifecycleScope
 import androidx.webkit.WebResourceErrorCompat
@@ -20,7 +27,11 @@ import dev.hotwire.turbo.errors.HttpError
 import dev.hotwire.turbo.errors.LoadError
 import dev.hotwire.turbo.errors.WebError
 import dev.hotwire.turbo.errors.WebSslError
-import dev.hotwire.turbo.http.*
+import dev.hotwire.turbo.http.TurboHttpClient
+import dev.hotwire.turbo.http.TurboHttpRepository
+import dev.hotwire.turbo.http.TurboOfflineRequestHandler
+import dev.hotwire.turbo.http.TurboPreCacheRequest
+import dev.hotwire.turbo.http.TurboWebViewRequestInterceptor
 import dev.hotwire.turbo.nav.TurboNavDestination
 import dev.hotwire.turbo.util.isHttpGetRequest
 import dev.hotwire.turbo.util.logEvent
@@ -30,7 +41,7 @@ import dev.hotwire.turbo.views.TurboWebView
 import dev.hotwire.turbo.visit.TurboVisit
 import dev.hotwire.turbo.visit.TurboVisitAction
 import dev.hotwire.turbo.visit.TurboVisitOptions
-import java.util.*
+import java.util.Date
 
 /**
  * This class is primarily responsible for managing an instance of an Android WebView that will
@@ -170,9 +181,27 @@ class TurboSession internal constructor(
         visitRendered(visit.identifier)
         visitCompleted(visit.identifier, restorationIdentifier)
 
+        webView.restoreCurrentVisit()
+
         return true
     }
 
+    /**
+     * Cache a snapshot of the current visit.
+     */
+    fun cacheSnapshot() {
+        if (!isReady) return
+
+        currentVisit?.let {
+            logEvent("cacheSnapshot",
+                "location" to it.location,
+                "visitIdentifier" to it.identifier
+            )
+
+            webView.cacheSnapshot()
+        }
+    }
+
     internal fun removeCallback(callback: TurboSessionCallback) {
         currentVisit?.let { visit ->
             if (visit.callback == callback) {

turbo/src/main/kotlin/dev/hotwire/turbo/views/TurboWebView.kt

@@ -60,6 +60,14 @@ open class TurboWebView @JvmOverloads constructor(context: Context, attrs: Attri
         runJavascript("turboNative.visitRenderedForColdBoot('$coldBootVisitIdentifier')")
     }
 
+    internal fun cacheSnapshot() {
+        runJavascript("turboNative.cacheSnapshot()")
+    }
+
+    internal fun restoreCurrentVisit() {
+        runJavascript("turboNative.restoreCurrentVisit()")
+    }
+
     internal fun installBridge(onBridgeInstalled: () -> Unit) {
         val script = "window.turboNative == null"
         val bridge = context.contentFromAsset("js/turbo_bridge.js")

turbo/src/test/kotlin/dev/hotwire/turbo/session/TurboSessionTest.kt

@@ -216,6 +216,7 @@ class TurboSessionTest {
 
         assertThat(session.restoreCurrentVisit(callback)).isTrue()
         verify(callback, times(2)).visitCompleted(false)
+        verify(webView, times(1)).restoreCurrentVisit()
     }
 
     @Test