fix subscribing triggering multiple saves (#920)

* fix subscribing triggering multiple saves

* linting

* linting

build/index.asset.php

@@ -1 +1 @@
-<?php return array('dependencies' => array('wp-api-fetch', 'wp-components', 'wp-data', 'wp-edit-post', 'wp-element', 'wp-hooks', 'wp-i18n', 'wp-plugins', 'wp-primitives'), 'version' => 'c9d2faeea53e70852af5');
+<?php return array('dependencies' => array('wp-api-fetch', 'wp-components', 'wp-data', 'wp-edit-post', 'wp-element', 'wp-hooks', 'wp-i18n', 'wp-plugins', 'wp-primitives'), 'version' => 'a701630770e7f696061b');

src/components/co-authors/index.jsx

@@ -10,7 +10,7 @@ import apiFetch from '@wordpress/api-fetch';
 import { ComboboxControl, Spinner } from '@wordpress/components';
 import { __ } from '@wordpress/i18n';
 import { applyFilters } from '@wordpress/hooks';
-import { useDispatch, useSelect, register, subscribe } from '@wordpress/data';
+import { useDispatch, useSelect, register } from '@wordpress/data';
 import { useEffect, useState } from '@wordpress/element';
 
 /**
@@ -165,27 +165,10 @@ const CoAuthors = () => {
 			return;
 		}
 
-		// Set selection.
-		setSelectedAuthors( authors );
-
-		// Set author store.
-		setAuthorsStore( authors );
+		updateAuthors( authors );
 
 	}, [ authors ] );
 
-	let checked = true;
-	subscribe( () => {
-		if ( isSavingPost() ) {
-			checked = false;
-		} else if ( ! checked ) {
-			if ( authors.length ) {
-				// Save author details to CAP.
-				saveAuthors( postId, authors );
-			}
-			checked = true;
-		}
-	});
-
 	return (
 		<>
 			{ Boolean( selectedAuthors.length ) ? (

src/index.js

@@ -4,6 +4,7 @@
 import { registerPlugin } from '@wordpress/plugins';
 import { PluginDocumentSettingPanel } from '@wordpress/edit-post';
 import { __ } from '@wordpress/i18n';
+import { select, subscribe } from "@wordpress/data";
 
 /**
  * Components
@@ -27,3 +28,22 @@ registerPlugin( 'plugin-coauthors-document-setting', {
 	render: PluginDocumentSettingPanelAuthors,
 	icon: 'users',
 } );
+
+// Save authors when the post is saved.
+// https://github.com/WordPress/gutenberg/issues/17632
+const { isSavingPost, getCurrentPost } = select("core/editor");
+const { getAuthors, saveAuthors } = select("cap/authors");
+
+let checked = true; // Start in a checked state.
+
+subscribe(() => {
+	if (isSavingPost()) {
+		checked = false;
+	} else if (!checked) {
+		const { id } = getCurrentPost();
+		const authors = getAuthors(id);
+		saveAuthors(id, authors);
+		checked = true;
+	}
+});
+