OnsenUI Tabbar Issue with React

Tabbar.jsx

import React from 'react';
import {Tabbar as _Tabbar} from 'react-onsenui';

class Tabbar extends React.Component{
    constructor(props){
        super(props);
        this.render = this.render.bind(this);
        this.componentWillReceiveProps = this.componentWillReceiveProps.bind(this);
        this.updateIndex = this.updateIndex.bind(this);

        this.state = {
            index: props.index ? props.index : 0
        }
    }
    updateIndex(e){
        this.setState((s,p)=>{
            return Object.assign({},s,{
                index:e.index
            });
        });
        if(this.props.onPostChange)
        {
            this.props.onPostChange(e);
        }
    }
    componentWillReceiveProps(nextProps) {

        if (nextProps.index !== this.props.index ) {
            this.setState((s,p)=>{
                return Object.assign({},s,{
                    index:nextProps.index
                });
            });
        }
        
   
    }
    render(){


        const useProps = Object.assign({},this.props,{
            onPostChange:this.updateIndex,
            index: this.state.index
        });
        return <_Tabbar {...useProps}>
            {this.props.children}
        </_Tabbar>;
    }
}


Tabbar.displayName = 'Tabbar';
export default Tabbar;