Add this function to your root App
component and then run it from your constructor after adding your font using these instructions. https://medium.com/react-native-training/react-native-custom-fonts-ccc9aacf9e5e
import {Text, TextInput} from 'react-native'
SetDefaultFontFamily = () => {
let components = [Text, TextInput]
const customProps = {
style: {
fontFamily: "Rubik"
}
}
for(let i = 0; i < components.length; i++) {
const TextRender = components[i].prototype.render;
const initialDefaultProps = components[i].prototype.constructor.defaultProps;
components[i].prototype.constructor.defaultProps = {
...initialDefaultProps,
...customProps,
}
components[i].prototype.render = function render() {
let oldProps = this.props;
this.props = { ...this.props, style: [customProps.style, this.props.style] };
try {
return TextRender.apply(this, arguments);
} finally {
this.props = oldProps;
}
};
}
}