AsyncStorage with ListView react native -

hi want make screen list can show user saved favourite. use local json file keep orginal data. , there want save favourite data on asyncstorage. asyncstorage returns promise , can't add on state. how can it?

const  ds = new listview.datasource({ rowhaschanged: (r1, r2) => r1 !== r2 }); let export default class list extends react.component {     constructor(props) {     let resultdata = new array;     super(props)     const datapoem =  asyncstorage.getitem('poemdb', (err, result) => {         = json.parse(result)         return result      });      console.log    this.state = {     datasource: ds.clonewithrows(datapoem),       counter: 1,       fontloaded: false,     };    } 

as said, asyncstorage.getitem returns promise, must deal promise.

need rely on response asyncstorage.getitem() may sure handled. can deal using then. once promise returned, state set asynchronously:

var datapoem = function(){   asyncstorage.getitem('poemdb').then((data) => {        this.setstate({          datasource: ds.clonewithrows(data),        });   }); } 

or can deal promise using await, concept came es7. example docs (https://facebook.github.io/react-native/docs/asyncstorage.html):

try {   const value = await asyncstorage.getitem('@mysuperstore:key');   if (value !== null){     // have data!!     console.log(value);   } } catch (error) {   // error retrieving data } 

or, create own promise, , return promise using resolve:

var getfavouritedata = new promise(function(resolve, reject){   asyncstorage.getitem().then((data) => {     resolve(data);   }); });