React-native-navigation: [V2] Navigation.constants() produces error.

[vnshgrg]

Issue Description

I am trying to get the statusBarHeight and topBarHeight but when used Navigation.constants() anywhere in my code throws Fatal error:
Exception '-[RNNSideMenuController tabBar]: unrecognized selector sent to instance 0x7f81a7070a00' was thrown while invoking getConstants on target RNNBridgeModule with params ( 216, 217 )

Code Snippets

const NavConstants = await Navigation.constants();
const statusBarHeight = NavConstants.statusBarHeight;
const topBarHeight = NavConstants.topBarHeight;
console.log(statusBarheight, topBarHeight);

Screenshot of error

---

Environment

• React Native Navigation version: ^2.12.0
• React Native version: 0.58.4
• Platform(s) (iOS, Android, or both?): iOS
• Device info (Simulator/Device? OS version? Debug/Release?): Both Simulator & Device

[barbarossusuz]

Same here

[guyca]

Have you tried getting Navigation.constants after root is displayed?

You can use the https://wix.github.io/react-native-navigation/#/docs/events?id=registercommandcompletedlistener listener for that

[preko96]

For me it's produced error on a root without a visible topbar and bottom tab.

[barbarossusuz]

Have you tried getting Navigation.constants after root is displayed?

You can use the https://wix.github.io/react-native-navigation/#/docs/events?id=registercommandcompletedlistener listener for that

Yes , actually im calling it after everything.

By the way, my previous RNN version was "2.1.3-snapshot.41" and it was fine-working, when i updated "2.13.0" then error showed up.

Thank you i will try with listener

[vnshgrg]

Have you tried getting Navigation.constants after root is displayed?

You can use the https://wix.github.io/react-native-navigation/#/docs/events?id=registercommandcompletedlistener listener for that

Yes, also tried getting constants with listeners but same error.

However I am not sure if I used the listeners properly. Here's the code I used:

const commandCompletedListener = Navigation.events().registerCommandCompletedListener(
    ({ commandId, completionTime, params }) => {
        console.log(commandId, params);
        if (
            commandId === "setRoot" &&
            params.layout.root.id === "MainSideMenu" // ID of my root sideMenu Stack
        ) {
            Navigation.constants().then(result => {
                console.log(result);
            });
        }
    }
);

[RiCoTeRoX]

Same here.

I added in the Navigation.events().registerAppLaunchedListener() but same error. :'(

when i reaload the app, the error disappear

[kriptonhaz]

just barely got the same problem, with or without listener produce the same error.

[matpaul]

As i understand this issue reproduce if contants() fired when no tabBars

here patch to Fix (just try catch on bottomTabsHeight)

patch-package
--- a/node_modules/react-native-navigation/lib/ios/Constants.m
+++ b/node_modules/react-native-navigation/lib/ios/Constants.m
@@ -15,7 +15,11 @@ + (CGFloat)statusBarHeight {
 }

 + (CGFloat)bottomTabsHeight {
-   return CGRectGetHeight(((UITabBarController *)((UIWindow *)(UIApplication.sharedApplication.windows[0])).rootViewController).tabBar.frame);
+   @try {
+       return CGRectGetHeight(((UITabBarController *)((UIWindow *)(UIApplication.sharedApplication.windows[0])).rootViewController).tabBar.frame);
+   } @catch (NSException *exception) {
+       return 0;
+   }
 }

 @end

[Axxxx0n]

@matpaul fix is working, is there PR for this?

[matpaul]

@Axxxx0n no, my patch is crutch fix ))

[mo-ah-dawood]

same here

[zabojad]

This is still happening with version 2.17.0 :(...

[ssg-luke]

Fixing this in my app was much simpler than I expected. I was grabbing constants during async componentDidMount(). I moved the code into async componentDidAppear() and have not seen the error since.

[renrizzolo]

I found that if I just call it inside registerAppLaunchedListener it can be called later on in componentDidMount / componentDidAppear without causing the crash.

Navigation.events().registerAppLaunchedListener(() => {
 Navigation.setRoot({...})
 Navigation.constants().then(res => console.log(res));
})

edit: I spoke too soon - crash still happens on first open ( but not on subsequent debugger reloads ).

[zabojad]

Still happening with RNN v 2.20.2

[mayconmesquita]

Still happening. This is a critical bug.

[daveyjones]

I was having the same issue when using Navigation.constants() on a project with no tab bar. Adding a try/catch as suggested by @matpaul resolved the issue for me, and seems like a perfectly valid permanent fix, so I submitted a PR: https://github.com/wix/react-native-navigation/pull/5201