Update: get argument from Bundle, SavedStateHandle

doctor-blue · Oct 4, 2021 · cbeb899 · cbeb899
1 parent ee40699
commit cbeb899
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Showing 3 changed files with 22 additions and 20 deletions.
diff --git a/.idea/gradle.xml b/.idea/gradle.xml
diff --git a/app/src/main/java/com/devcomentry/composenavigation/MainActivity.kt b/app/src/main/java/com/devcomentry/composenavigation/MainActivity.kt
@@ -9,7 +9,7 @@ import androidx.navigation.compose.NavHost
 import androidx.navigation.compose.rememberNavController
 import com.devcomentry.composenavigation.ui.screen.*
 import com.devcomentry.lib.composable
-import com.devcomentry.lib.getParamFromArg
+import com.devcomentry.lib.from
 
 class MainActivity : AppCompatActivity() {
     override fun onCreate(savedInstanceState: Bundle?) {
@@ -36,9 +36,10 @@ class MainActivity : AppCompatActivity() {
 
                         composable(Screen.Screen2, Screen2Argument()) {
                             // get data from arguments
-                            Screen2(
-                                it.arguments?.getParamFromArg(Screen2Argument()) as Screen2Argument
-                            )
+                            it.arguments?.let {  bundle->
+                                val argument = Screen2Argument().from(bundle)
+                                Screen2(argument)
+                            }
                         }
 
                     }

diff --git a/lib/src/main/java/com/devcomentry/lib/Navigation.kt b/lib/src/main/java/com/devcomentry/lib/Navigation.kt
@@ -6,15 +6,26 @@ import androidx.lifecycle.SavedStateHandle
 import androidx.navigation.*
 import androidx.navigation.compose.ComposeNavigator
 
-fun Bundle.getParamFromArg(argument: Argument): Argument {
-    val fields = argument.javaClass.declaredFields
+fun <T : Argument> T.from(bundle: Bundle): T {
+    val fields = this.javaClass.declaredFields
     for (field in fields) {
         field.isAccessible = true
-        if (field.name != "\$stable") {
-            field.set(argument, this[field.name])
+        if (field.name != "\$stable" && bundle.containsKey(field.name)) {
+            field.set(this, bundle[field.name])
         }
     }
-    return argument
+    return this
+}
+
+fun <T : Argument> T.from(state: SavedStateHandle): T {
+    val fields = this.javaClass.declaredFields
+    for (field in fields) {
+        field.isAccessible = true
+        if (field.name != "\$stable" && state.contains(field.name)) {
+            field.set(this, state[field.name])
+        }
+    }
+    return this
 }
 
 fun NavGraphBuilder.composable(
@@ -42,15 +53,4 @@ fun NavGraphBuilder.composable(
             }
         }
     )
-}
-
-fun SavedStateHandle.get(argument: Argument): Argument {
-    val fields = argument.javaClass.declaredFields
-    for (field in fields) {
-        field.isAccessible = true
-        if (field.name != "\$stable") {
-            field.set(argument, this[field.name])
-        }
-    }
-    return argument
 }