gistfile1.js

class MainView extends React.Component {
    _addEntry(e) {
        this.props.navigator.push({
            title: 'New',
            component: AddEntryView,
            rightButtonTitle: 'Save',
            onRightButtonPress: (e) => {
                // save
            },
        });
    }
}

class MainView extends React.Component {
    _addEntry(e) {
        this.props.navigator.push({
            title: 'New',
            component: AddEntryView,
            rightButtonTitle: 'Save',
            onRightButtonPress: () => { this._saveEntry(e) },
        });
    }
}