Apps that dynamically calculate height are broken, during app.activated core event document.body.clientHeight/scrollHeight is 0

[1951FDG]

Problem

Apps dynamically calculating their height during app.activated core event, are not able to resize correctly due to 0 height being returned. I believe this has been an issue since about 1 month ago.

This issue can be reproduced while switching tabs back and forth in Zendesk.

Whenever this happens a workaround is to refresh the apps, which will fire app.registered core event again.

Some of the apps affected are:

• my custom app (private repo)
• https://www.zendesk.com/marketplace/apps/support/116762/ticket-history/
• https://www.zendesk.com/marketplace/apps/support/6536/user-data/

Example code to debug

/**
 * Event Listener that fires when the app becomes active. Resizes the app's iframe dimensions.
 */
client.on('app.activated', (event) => {
  client.invoke('resize', { height: `${document.body.clientHeight}px` }).then((data) => {
    console.error(`body client height: ${document.body.clientHeight}`);
    console.error(`body scroll height: ${document.body.scrollHeight}`);
    console.error(`html client height: ${document.documentElement.clientHeight}`);
    console.error(`html scroll height: ${document.documentElement.scrollHeight}`);
    console.error(`${getComputedStyle(document.documentElement).getPropertyValue('height')}`);
  });
});

Environment

Google Chrome - Version 100.0.4896.127

Additional info:

core_api/#resize

Note: Ensure that you always invoke a resize whenever the app.activated core event is fired if your app is dynamically calculating it's height. This is considered as a best practice to prevent a resizing issue where the body scrollHeight of the iframe would return a value of 0 whenever an agent switches to another ticket tab, while your app in the original tab was still in the process of being loaded.