FileReader onload/onloadend/onerror not fire on ios

FileReader’s event handlers (e.g. onload, onloadend, onerror) cannot be fired on ios, but work on mac safari when in mode of ionic serve. Furthermore, same issue happens when using cordova-plugin-file and ionic-native/file, so that then()/catch() also cannot be fired on ios.

This problem blocks my project.

You have to remove the application from the device, and you must enable the permissions again.

Having removed app, only the error thrown by the first called function can be caught. But then neither then() nor catch() of any file function works.

And what permissions need enable?

Referring to this comment, the solution is to re-order the index.html of your app so that the polyfills.js (which includes zone.js and a few other things) is included before cordova.js.
Joe’s comment

Aha, so does it. Thx a lot!

Thx a lot. You save my life!!!