Widgets are now also blocks. In the completely new widget view under Design › Widgets, both the known and all other blocks can now be created as widgets. It is still possible to move temporarily unneeded widgets to the inactive area so that they can be restored later without much effort. A detailed description of this feature, including how to disable it, can be found in the official Dev Note.
If you like, you can already experiment with block-based themes. However, the feature is still in beta status, since themes have to be developed separately. Accordingly, the support is currently only available in a few themes. In order to be able to use it fully, you need the Gutenberg plugin and a corresponding theme. For me, the block version of Twenty Twentyone was a good start.
Templates work completely differently in block-based themes. What used to be PHP templates are now pure HTML files that simply contain Gutenberg blocks. In order to still implement dynamic content such as the loop or post title, content and comments, there are new blocks that enable precisely these functions. In addition, it is possible with template parts to imitate PHP includes and outsource repetitive components.
The particularly cool thing about it: The templates and template parts can be edited in the WordPress backend. This means anyone who has a bit of patience can adjust the structure of the page with the template editor, even without programming knowledge. This uses the blocks and mechanisms known from the previous editor to deal with it. New templates can also be easily created.
So we can expect a completely new generation of themes that work fundamentally differently than previous themes with PHP templates. There is currently no clear migration path as to how classic PHP-based themes can be converted into block themes. There will probably be full site editing support for individual templates for theme developers. However, details have not yet been determined.
An important part and a very useful extension for existing themes is the theme.json file. Theme developers can use this file to make many settings that previously required PHP functions. This makes it very easy to customize colors, fonts and many Gutenberg options in general. If you want to know more, you can take a look at the dev note for theme.json.
Similar to theme.json, the new block.json file also allows developers to set block metadata and some block settings more easily. Again, there are a few things to consider that would go beyond this post, hence the reference to the Block API Dev Note.
As in my last release reviews, here are a few more small but equally interesting changes from my point of view:
WordPress 5.8 is a big step towards Full Site Editing. I find the current developments very exciting, there is upheaval in the air. There is a lot that is new for theme developers in particular and development is currently progressing very quickly. For users, WordPress is becoming more of a flexible page builder with each release. WP 5.8 is the logical continuation of the Gutenberg roadmap.