How to hide Webpage Not Available in WebViewer?

First of all, I am sorry if this question is not covered in App Inventor, but I don't know where to ask. I hope this is the correct forum. 

The idea is to hide a webpage viewer/or create my own webpage not available page instead of showing the default page if there is connection error.

I found some solutions that I never tried because I don't know how to implement the codes in App Inventor.

http://upshots.org/android/android-replace-webview-40

and

Prevent WebView from displaying “web page not available”

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As WebViewer component doesn't have an "Error Occured" event block which would return error code, so this may be challenging unless the AI team or someone modifies the component code.

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Try this Check Internet Connection method.

Check Internet Connection In App Inventor

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Thank you Vipul. I saw this solution before and never thought it will work. :)

See my edit.

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Thank you Pavitra. Yes it is quite challenging. See my edit.

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