Was NavigationLock designed for mobile devices and back to previous page?

[hariywill]

I tried NavigationLock in one of my project. On PC, I am not getting alerts when I click back to previous page button. On iPad, I am not getting alert box at all no matter it's refreshing page or type in new url. Are these intended by design or bugs?

[gfoidl]

@MackinnonBuck please have a look here (I saw you were involved in that feature, so I hope you're the right person to ask)

[MackinnonBuck]

@hariywill, how is your NavigationLock configured? Does it only specify ConfirmExternalNavigation="true"? If so, note that this will only cause an alert to display for external navigations, i.e., navigations that require a full page reload. If you want to display an alert for navigations that get handled by Blazor's client-side navigation, you can specify an OnBeforeInternalNavigation callback and use it to display a confirmation prompt via JS interop. You'll have to provide both NavigationLock parameters if you want to handle both cases.

For the iPad-specific issue, it looks like you might be experiencing https://stackoverflow.com/questions/3239834/window-onbeforeunload-not-working-on-the-ipad. Behind the scenes, NavigationLock uses the beforeunload event to display a confirmation prompt when performing an "external" navigation, so if a browser doesn't support that event, NavigationLock won't display the prompt.