Backport tweaks from #5975

Author: BoD

docs/source/tutorial/08-add-a-details-view.mdx

@@ -158,7 +158,7 @@ fun LaunchDetails(launchId: String) {
 Now use the state to show the appropriate UI:
 
 ```kotlin title="app/src/main/java/com/example/rocketreserver/LaunchDetails.kt"
-‎    // Use the state
+    // Use the state
     when (val s = state) {
         Loading -> Loading()
         is ProtocolError -> ErrorMessage("Oh no... A protocol error happened: ${s.exception.message}")
@@ -186,7 +186,7 @@ private sealed interface LaunchDetailsState {
 }
 ```
 
-Then, in the `try` block, check for `response.hasErrors()` and wrap the result in the new state:
+Then, in the `when` block, check for `response.hasErrors()` and wrap the result in the new state:
 
 ```kotlin title="app/src/main/java/com/example/rocketreserver/LaunchDetails.kt"
 state = when {
@@ -202,6 +202,16 @@ state = when {
 }
 ```
 
+You should also update the conditional expression to handle the `ApplicationError` case:
+```kotlin title="app/src/main/java/com/example/rocketreserver/LaunchDetails.kt"
+    when (val s = state) {
+        Loading -> Loading()
+        is ApplicationError -> ErrorMessage(text = s.errors.first().message) // highlight-line
+        is ProtocolError -> ErrorMessage("Oh no... A protocol error happened: ${s.exception.message}")
+        is Success -> LaunchDetails(s.data)
+    }
+```
+
 `response.errors` contains details about any errors that occurred. Note that this code also null-checks `response.data!!`. In theory, a server should not set `response.data == null` and `response.hasErrors == false` at the same time, but the type system cannot guarantee this.
 
 To trigger an error, replace `LaunchDetailsQuery(launchId)` with `LaunchDetailsQuery("invalidId")`. Disable airplane mode and select a launch. The server will send this response: