Re-implement the Network Admin “Sites” dashboard using DataViews and DataForm

[realloc]

The current Network Admin → Sites screen is still based on the legacy WP_List_Table implementation. To align it with modern WordPress interfaces, we propose re-implementing this screen using DataViews and DataForm from the Gutenberg project.

This would improve consistency across the admin, provide more flexible filtering and bulk actions, and make the codebase easier to extend and maintain.

Initial steps:

• Create or re-use the container in the Network Admin where the JS application will be mounted.
• Create a REST API endpoint that exposes get_sites() via GET.
• Add scripts to interact with this endpoint using DataViews.
• Create a REST API endpoint that accepts POST requests to save changes.
• Add scripts to interact with this endpoint using DataForm.

Notes:

• This is a feature request and will require time and several iterations.
• The first implementation can be minimal (just listing sites), with filters, sorting, and bulk actions added in later iterations.
• Feedback from both developers and multisite users will be crucial in shaping the final interface.

Trac ticket: https://core.trac.wordpress.org/ticket/63885

[jeremyfelt]

FWIW, I haven't reviewed any code, but the demo of this is a fantastic improvement so far over the current sites table.

Related ticket for a Sites endpoint, which would need to be available for this view to be implemented: https://core.trac.wordpress.org/ticket/40365

[spacedmonkey]

@realloc There is already a ticket for the site endpoints at #40365. Better yet, there are already site endpoints in this ​official plugin.

I think we should consider landing #40365 first, by porting that plugin to a core patch and add unit tests. Then we can revisit this ticket.

[realloc]

I agree #40365 is the prerequisite. Let’s focus on getting the site endpoints into core first. At the same time, I see this ticket as complementary. We can continue UI exploration with DataViews in parallel so the endpoints are validated by a real consumer once they land.