There is some more clean up I'd like to do, but I wanted to get this open so that the changes to the Gutenberg client can be discussed.

As I see it, the Client will now need to do a batch request to update all dirty widgets. Then if the order of widgets has changed, a PUT to the sidebar that contains the ordered list of widget IDs like { widgets: [ text-1, rss-1 ] }.

@TimothyBJacobs I can't see this working in postman.

Don't we need to load the file here

and setup the class here

If you can do this, I will continue my testing.

@spacedmonkey yep its completely broken at the moment, sorry for the early ping. Working on a fix.

Huzzah, PHPunit is now passing! Will start on your suggestions @spacedmonkey in a bit.

In my testing, a widget with namespace works.

5:
description: "A wibble form for your site."
id: "wibble1-2"
id_base: "wibble1"
name: "Wibble!"
number: 2
rendered: "<section id="wibble1-2" class="widget widget_wibble1"><h2 class="widget-title">TRfsd</h2></section>"
settings: {title: "TRfsd"}
sidebar: "sidebar-1"
widget_class: "WordPressWidgetBoilerplate\WordPress\WP_Widget_Wibble"
_links: {collection: Array(1), self: Array(1), wp:sidebar: Array(1), curies: Array(1)}
__proto__: Object

@spacedmonkey looks like the tests need to be updated for the new fields.

@TimothyBJacobs I am thinking about creating that widget_type api and moving some of the fields out into that.

👍 let's get the tests passing again here first.

@TimothyBJacobs this PR removes an endpoint that's currently used by the edit-widgets package which means that in order to merge it we'll have to couple it with, potentially lengthy, JS changes. How about a multi-step approach where we'd just rename the old endpoint to, let's say, legacy-sidebars, migrate the React part to the new endpoints, and remove legacy-sidebars afterwards?

The failing test is test_all_supported which looks to be failing on main as well.

I checked out this PR and tested adding, removing and updating blocks and legacy widgets in the widgets editor. The only problem I could spot is that reference widgets (widgets registered without using WP_Widget) no longer can be saved.

You can test this by adding this code, going to Appearance → Widgets, inserting a Marquee Greeting into a widget area, then clicking Save.

wp_register_sidebar_widget(
	'marquee_greeting',
	'Marquee Greeting',
	function() {
		$greeting = get_option( 'marquee_greeting', 'Hello!' );
		printf( '<marquee>%s</marquee>', esc_html( $greeting ) );
	}
);

wp_register_widget_control(
	'marquee_greeting',
	'Marquee Greeting',
	function() {
		if ( isset( $_POST['marquee-greeting'] ) ) {
			update_option(
				'marquee_greeting',
				sanitize_text_field( $_POST['marquee-greeting'] )
			);
		}

		$greeting = get_option( 'marquee_greeting' );
		?>
		<p>
			<label for="marquee-greeting">Greeting:</label>
			<input
				id="marquee-greeting"
				class="widefat"
				name="marquee-greeting"
				type="text"
				value="<?= esc_attr( $greeting ) ?>"
				placeholder="Hello!"
			/>
		</p>
		<?php
	}
);

Thanks for testing @noisysocks! I've pushed a fix. The issue was that reference widgets always have an ID, so it was detected as an update. However, the widget wasn't yet assigned to a sidebar which the update endpoint expects. I've fixed this to allow for reference widgets to pass the sidebar id to update and treat that as creation.

Thanks for testing @noisysocks!