Accessing element height in NativeScript

Question

I am trying to write a native script app which retrieves the rendered height of the bottle view/element in my xml. I have tried the following code, but unfortunately, I get an error (shown below). Any guidance would be much appreciated.

JS:

var viewModule = require("ui/core/view");
var page;

exports.fabTap = function (args) {
      page = args.object;
      var bottle = page.getViewById("bottle");
      console.log("Height: " + bottle.height);
  }

XML:

<Page xmlns="http://schemas.nativescript.org/tns.xsd" xmlns:FAB="nativescript-floatingactionbutton" actionBarHidden="true" loaded="pageLoaded">
  <GridLayout columns="*, *, *, *" rows="15*, 5*, 20*, 5*, 5*, 5*, 5*, 20*, 20*" width="100%" height="100%" style.backgroundColor="white" >
    <Image src="res://logo" row="0" col="1" colSpan="2" stretch ="aspectFit" class="logo"/>
    <Image id="bottle" src="res://bottle_outline" row="2" col="0" rowSpan="6" colSpan="2" stretch="aspectFit"/>
  </GridLayout>
</Page>

Cannot read property 'height' of undefined.

Answer 1

To get the calculated size of the view, not what you declared in the styles:

const viewModule = require("ui/core/view");
let page;

exports.pageLoaded = function (args) {
   page = args.object;
}

exports.fabTap = function (args) {
   const bottle = page.getViewById("bottle");
   console.log("Height: " + bottle.getActualSize().height);
}