Interact to react native wrapper app from your web-app using message passing.

rn-host.js

function rnIsMobileApp() {
  // check website open in browser or mobile app
  return window.ReactNativeWebView !== undefined;
}


// Returns if a value is a string
function rnIsString(value) {
  return typeof value === 'string' || value instanceof String;
}

function rnPostMessage(message) {
  if (rnIsMobileApp()) {
    //check if it works with iOS
    if (!rnIsString(message)) {
      if (message.type !== undefined && message.data != undefined) {
        message = JSON.stringify(message);
      } else {
        console.log(
          'some error message is not valid {type, data} props needed ',
          message
        );
      }
    }
    window.ReactNativeWebView.postMessage(message);
  }
}

function rnProcessResponse(onSuccess, onFail, type) {
  var doc =
    navigator.userAgent.match(/(iPhone|iPod|iPad)/i) == null ?
    document :
    window;
  doc.addEventListener('message', function(response) {
    try {
      response = JSON.parse(response.data);
      if (response.type == type) {
        response.status == 200 ?
          onSuccess(response.message) :
          onFail(response.message);
      }
    } catch (e) {
      console.error(e, response);
    }
  });
}

function rnOpenLink(link) {
  if (rnIsMobileApp()) {
    var message = {
      type: 'open_Link',
      data: link,
    };
    rnPostMessage(message);
  } else {
    //for desktop/mobile web open
    window.location.href = link;
  }
}

function rnShareImageIntent(onSuccess, onFail, data) {
  if (rnIsMobileApp()) {
    var message = {
      type: 'share_image_intent',
      data: data,
    };
    rnPostMessage(message);
    rnProcessResponse(onSuccess, onFail, 'type_share_image_intent');
  } else {
    //for desktop/mobile web
    return false;
  }
}