Custom notification in WordPress Gutenberg

gutenbeg-notification.js

// context check: if this is an rsvpmaker template, this will have be available as localized data from PHP
if((typeof rsvpmaker_json !== 'undefined' ) && rsvpmaker_json.projected_url) {

		let wasSavingPost = wp.data.select( 'core/editor' ).isSavingPost();
		let wasAutosavingPost = wp.data.select( 'core/editor' ).isAutosavingPost();
		let wasPreviewingPost = wp.data.select( 'core/editor' ).isPreviewingPost();
		// determine whether to show notice
		subscribe( () => {
			const isSavingPost = wp.data.select( 'core/editor' ).isSavingPost();
			const isAutosavingPost = wp.data.select( 'core/editor' ).isAutosavingPost();
			const isPreviewingPost = wp.data.select( 'core/editor' ).isPreviewingPost();
			const hasActiveMetaBoxes = wp.data.select( 'core/edit-post' ).hasMetaBoxes();
			
			// Save metaboxes on save completion, except for autosaves that are not a post preview.
			const shouldTriggerTemplateNotice = (
					( wasSavingPost && ! isSavingPost && ! wasAutosavingPost ) ||
					( wasAutosavingPost && wasPreviewingPost && ! isPreviewingPost )
				);

			// Save current state for next inspection.
			wasSavingPost = isSavingPost;
			wasAutosavingPost = isAutosavingPost;
			wasPreviewingPost = isPreviewingPost;
	
			if ( shouldTriggerTemplateNotice ) {
	wp.data.dispatch('core/notices').createNotice(
		'info', // Can be one of: success, info, warning, error.
		__('After updating this template, click'), // Text string to display.
		{
			id: 'rsvptemplateupdate', //assigning an ID prevents the notice from being added repeatedly
			isDismissible: true, // Whether the user can dismiss the notice.
			// Any actions the user can perform.
			actions: [
				{
					url: rsvpmaker_json.projected_url,
					label: __('create / update events')
				}
			]
		}
	);
			}
			/* placeholder for logic to remove notice
			else {
				console.log('remove notice');
			}
			*/
} );
	
}