Create a new Gutenberg store keeping track of the selectedSiteId changes

Author: Copons

client/gutenberg/editor/calypso-store/actions.js

@@ -0,0 +1,4 @@
+export const setSelectedSiteId = selectedSiteId => ( {
+	type: 'GUTENLYPSO_SELECTED_SITE_ID_SET',
+	selectedSiteId,
+} );

client/gutenberg/editor/calypso-store/index.js

@@ -0,0 +1,19 @@
+/**
+ * WordPress Dependencies
+ */
+import { registerStore } from '@wordpress/data';
+
+/**
+ * Internal dependencies
+ */
+import reducer from './reducer';
+import * as actions from './actions';
+import * as selectors from './selectors';
+
+const store = registerStore( 'gutenberg/calypso', {
+	reducer,
+	actions,
+	selectors,
+} );
+
+export default store;

client/gutenberg/editor/calypso-store/reducer.js

@@ -0,0 +1,10 @@
+/* eslint-disable wpcalypso/import-docblock */
+/**
+ * WordPress dependencies
+ */
+import { combineReducers } from '@wordpress/data';
+
+const selectedSiteId = ( state = null, action ) =>
+	'GUTENLYPSO_SELECTED_SITE_ID_SET' === action.type ? action.selectedSiteId : state;
+
+export default combineReducers( { selectedSiteId } );

client/gutenberg/editor/calypso-store/selectors.js

@@ -0,0 +1 @@
+export const getSelectedSiteId = state => state.selectedSiteId;

client/gutenberg/editor/controller.js

@@ -12,7 +12,7 @@ import { has, set, uniqueId } from 'lodash';
  * WordPress dependencies
  */
 import { setLocaleData } from '@wordpress/i18n';
-import { dispatch } from '@wordpress/data';
+import { dispatch, select } from '@wordpress/data';
 
 /**
  * Internal dependencies
@@ -110,6 +110,22 @@ export const loadGutenbergBlockAvailability = store => {
 	} );
 };
 
+export const resetGutenbergState = ( registry, selectedSiteId ) => {
+	// Always reset core/editor, core/notices, and other UI parts
+	registry.reset( 'core/editor' );
+	registry.reset( 'core/notices' );
+	dispatch( 'core/edit-post' ).closePublishSidebar();
+	dispatch( 'core/edit-post' ).closeModal();
+
+	// Only reset core/data on site change
+	const previousGutenbergSiteId = select( 'gutenberg/calypso' ).getSelectedSiteId();
+
+	if ( !! previousGutenbergSiteId && previousGutenbergSiteId !== selectedSiteId ) {
+		registry.reset( 'core/data' );
+	}
+	dispatch( 'gutenberg/calypso' ).setSelectedSiteId( selectedSiteId );
+};
+
 export const redirect = ( { store: { getState } }, next ) => {
 	const state = getState();
 	const siteId = getSelectedSiteId( state );
@@ -140,11 +156,7 @@ export const post = async ( context, next ) => {
 
 		const { Editor, registry } = initGutenberg( userId, context.store );
 
-		// Reset the Gutenberg state
-		registry.reset( 'core/editor' );
-		registry.reset( 'core/notices' );
-		dispatch( 'core/edit-post' ).closePublishSidebar();
-		dispatch( 'core/edit-post' ).closeModal();
+		resetGutenbergState( registry, siteId );
 
 		return props => (
 			<Editor { ...{ siteId, postId, postType, uniqueDraftKey, isDemoContent, ...props } } />

client/gutenberg/editor/init.js

@@ -61,12 +61,15 @@ const addResetToRegistry = registry => {
 export const initGutenberg = once( ( userId, store ) => {
 	debug( 'Starting Gutenberg editor initialization...' );
 
+	const registry = use( addResetToRegistry );
+
 	debug( 'Registering data plugins' );
 	const storageKey = 'WP_DATA_USER_' + userId;
 	use( plugins.persistence, { storageKey: storageKey } );
 	use( plugins.controls );
 
-	const registry = use( addResetToRegistry );
+	debug( 'Initializing gutenberg/calypso store' );
+	require( 'gutenberg/editor/calypso-store' );
 
 	// We need to ensure that core-data is loaded after the data plugins have been registered.
 	debug( 'Initializing core-data store' );