Full site editing is a new WordPress feature that gives you the ability to use blocks outside the content. Full site editing and global styles are both experimental features and requires you to first install the Gutenberg plugin.
From Gutenberg version 9.3.0, you no longer need to enable full site editing manually. It is enabled once you activate a full site editing theme.
You will build the entire page layout using blocks -everything you see on a page is a block.
And yes, it means that you can finally use the cover block as your header image :).
A page can consist of a single template, or, it can be a combination of template parts. You can create, edit and preview templates and template parts in the new site editor:
You can use different template parts for different posts and pages.
Because the pages are built using blocks -and nothing but blocks, both the Customizer and widgets are removed when full site editing is enabled.
There are still unanswered question about the Customizer only settings (like the site icon) and how we can make them work with full site editing.
In the site editor you can also find a new sidebar panel named global styles.
Here, you can select site wide defaults both for the website and for different block types.
In November 2020 when this lesson is written, the features are still limited to colors, font size and line height. -And only for some blocks.
There are plans to support these options in more blocks.
The available options will likely be extended to include:
These features are still being developed and may change.
With full site editing, developers will use HTML templates instead of PHP files, and block comments and markup instead of PHP functions.
Example block markup:
<!-- wp:paragraph --> <p>Welcome to the world of blocks.</p> <!-- /wp:paragraph -->
Theme authors can no longer rely on the Customizer for global options.
Instead, global styles and block patterns have more important roles and that is why this course also includes lessons about block patterns.
When a design is updated and saved in the site editor, the changes are saved in the WordPress database. The files inside the theme folder are not changed, and changes made to the files are not reflected on the website; the saved templates are used instead.
The content and markup are saved in two new custom post types: Templates and template parts. This means that a layout can reused, even when you install a different theme.
This puts an emphasis on making sure that the blocks in the editor and front match, and that theme developers test their blocks carefully.
You can create and preview layouts by placing your blocks in the site editor. When the design is ready, export it as a .zip file with HTML files, directly from the editors tools and options modal:
The export is not a complete theme, but it contains the markup for the blocks and can be used as the base for a new theme.
Block-based themes use a new configuration file called experimental-theme.json. With this file, theme developers use JSON format to define defaults for blocks. Such as background color, text color and font size.
The file is used to:
The role of the theme.json file continues to evolve with every new version of Gutenberg. What is clear is that it will have a major part in future theme development.
Full site editing brings many changes. It also lowers the entry barrier for new theme authors.
They no longer have to be concerned with the Customizer, custom widgets or post meta boxes, and can focus more on extending and styling blocks.
Full site editing themes will be easier to build; they will contain fewer files and less CSS.
Having said that, existing theme developers may still find the transition and change of mindset difficult.
Right now, there is no clear path for how to convert a PHP based theme to a full site editing theme.