javascript - React Native: can't a method be used from 'routeMapper'? -

i’m using react native drawer of https://github.com/root-two/react-native-drawer

i trying call method opendrawer() passing in variable navigationbarroutemapper. tried logging inside navigationbarroutemapper, , logs variable passed in correctly. when used inside navigationbarroutemapper, clicking left navigation button of ‘open drawer’, not anything:

class drawerpractice extends component { ...    opendrawer(){     this._drawer.open()   }    render() {     return (   <drawer     content={<drawerpanel/>}     opendraweroffset={100}     ref={(ref) => this._drawer = ref}     type='static'     tweenhandler={drawer.tweenpresets.parallax}   >         <navigator           configurescene={this.configurescene}           initialroute={{name: 'start', component: start}}           renderscene={this.renderscene}           style={styles.container}           navigationbar={             <navigator.navigationbar               style={styles.navbar}               routemapper={navigationbarroutemapper(this.opendrawer)}             />           }         />   </drawer>     );   } }  var navigationbarroutemapper = opendrawer => ({   leftbutton(route, navigator, index, navstate){       return(           <touchablehighlight onpress={()=>{opendrawer}}>               <text>open menu</text>           </touchablehighlight>       )     }   },... 

why may issue?

on constructor() method add this: this.opendrawer = this.opendrawer.bind(this);

you're using this on wrong scope.