Understanding Android's webview addjavascriptinterface

Question

I know that to interact from Javascript to Java you have to inject a Java object using the addjavascriptInterface method in webview.

Here is the problem I am facing.

Answer 1

Ensure your Javascript objects declared in your HTML / Javascript that you need to access from Java are declared global otherwise they will most likely be collected. I have code that does this (where Android is my interface added with addJavascriptInterface):

The getLocation method invokes Android's LocationManager.requestSingleUpdate which then invokes the callback when the LocationListener fires.

Without the "var" I find that by the time the location lookup invokes the callback the callback function has been garbage collected.