Admin manifest fails to be created if admin bar is not present on the page

[pierlon]

Description

If the admin bar is not present on an admin page, the admin manifest script fails with the error:

Uncaught TypeError: Window.getComputedStyle: Argument 1 is not an object.

That error can be traced back to here:

gutenberg/packages/admin-manifest/src/index.js

Lines 109 to 110 in 34d1a96

	const adminBar = document.getElementById( 'wpadminbar' );
	const { color, backgroundColor } = window.getComputedStyle( adminBar );

I experienced this error when navigating to the Onboarding Wizard in the AMP for WordPress plugin.

Expected behaviour

Admin manifest should still be created if admin bar is not present on the page.

Actual behaviour

Admin manifest is not created if admin bar is not present on the page.

Screenshots or screen recording (optional)

WordPress information

• WordPress version: 5.8
• Gutenberg version: 11.1.0
• Are all plugins except Gutenberg deactivated? No, the AMP for WordPress plugin is activated
• Are you using a default theme (e.g. Twenty Twenty-One)? Yes

Device information

• Device: Desktop
• Operating system: Linux
• Browser:Firefox 90

[westonruter]

Introduced in #33102.

I suppose it should check if adminBar is null, and if so, use default values for color and backgroundColor.

IMO, the PWA icon shouldn't be using the WP logo anyway, but rather it should be using the site icon: GoogleChromeLabs/pwa-wp#295 (comment)

See also GoogleChromeLabs/pwa-wp#569.

cc @ellatrix

[ellatrix]

@pierlon Could you share a screenshot of the page? Is the admin menu visible on the page?

[westonruter]

@ellatrix No, neither the admin menu nor the admin toolbar are shown on this page.

[westonruter]

It's a full-screen "wizard". In the AMP plugin, you can access it by activating and navigating to the onboarding wizard. I recall Yoast and WooCommerce have something similar.