blob: iframe not working in Cordova on Android

Question

I'm using Cordova 7.0.1, and trying to set the contents of an iframe using a generated blob: url, but the result is an empty iframe, and no console errors.

If I disable blob: urls in the content security policy, I get an error as I would expect. So I'm fairly confident my problem is not the CSP.

I've also whitelisted * in config.xml to no avail:

<allow-navigation href="*" />
<allow-intent href="*" />

Constructing a data: url works. Why doesn't blob:?

Ages ago, probably with Cordova 5, I had this working. Is this no longer permitted? Is there a way to allow it again, or an alternative method?

Answer 1

To allow blob scheme, we have to set the following in config.xml:

<allow-navigation href="blob:*" />

More info on this is available on Issue:CB9558 under official apache cordova issue tracker.