EOSJS - ReactNative -- undefined is not an object (evaluating 'self.fetch')

[amolmaid]

Hi, I have been following instructions from link https://github.com/EvaCoop/eosjs-react-native , to setup eosjs on already-build react-native app.
I have installed related dependencies as well like react-native-browser-polyfill and react-native-hockeyapp

My build completes successfully and runs fine But I am facing following error when I open my app in mobile.
undefined is not an object (evaluating 'self.fetch')

Kindly guide for the same.

[raphaelgodro]

Create a variable var self = this; before the declaration.