Fix: Follow discussion settings in the comments block edit (#44463)

Respect discussion settings in the new Comments block while working in the Site Editor. We are loading some placeholders, and they should follow the discussion settings as much as possible in order to reflect the frontend output.

Co-authored-by: Bernie Reiter <ockham@raz.or.at>

packages/block-library/src/comment-template/edit.js

@@ -37,6 +37,7 @@ const TEMPLATE = [
  *
  * @param {Object}  settings                       Discussion Settings.
  * @param {number}  [settings.perPage]             - Comments per page setting or block attribute.
+ * @param {boolean} [settings.pageComments]        - Enable break comments into pages setting.
  * @param {boolean} [settings.threadComments]      - Enable threaded (nested) comments setting.
  * @param {number}  [settings.threadCommentsDepth] - Level deep of threaded comments.
  *
@@ -45,42 +46,53 @@ const TEMPLATE = [
  */
 const getCommentsPlaceholder = ( {
 	perPage,
+	pageComments,
 	threadComments,
 	threadCommentsDepth,
 } ) => {
-	// In case that `threadCommentsDepth` is falsy, we default to a somewhat
-	// arbitrary value of 3.
-	// In case that the value is set but larger than 3 we truncate it to 3.
-	const commentsDepth = Math.min( threadCommentsDepth || 3, 3 );
+	// Limit commentsDepth to 3
+	const commentsDepth = ! threadComments
+		? 1
+		: Math.min( threadCommentsDepth, 3 );
 
-	// We set a limit in order not to overload the editor of empty comments.
-	const defaultCommentsToShow =
-		perPage <= commentsDepth ? perPage : commentsDepth;
-	if ( ! threadComments || defaultCommentsToShow === 1 ) {
-		// If displaying threaded comments is disabled, we only show one comment
-		// A commentId is negative in order to avoid conflicts with the actual comments.
-		return [ { commentId: -1, children: [] } ];
-	} else if ( defaultCommentsToShow === 2 ) {
-		return [
-			{
-				commentId: -1,
-				children: [ { commentId: -2, children: [] } ],
-			},
-		];
-	}
+	const buildChildrenComment = ( commentsLevel ) => {
+		// Render children comments until commentsDepth is reached
+		if ( commentsLevel < commentsDepth ) {
+			const nextLevel = commentsLevel + 1;
 
-	// In case that the value is set but larger than 3 we truncate it to 3.
-	return [
-		{
-			commentId: -1,
-			children: [
+			return [
 				{
-					commentId: -2,
-					children: [ { commentId: -3, children: [] } ],
+					commentId: -( commentsLevel + 3 ),
+					children: buildChildrenComment( nextLevel ),
 				},
-			],
-		},
+			];
+		}
+		return [];
+	};
+
+	// Add the first comment and its children
+	const placeholderComments = [
+		{ commentId: -1, children: buildChildrenComment( 1 ) },
 	];
+
+	// Add a second comment unless the break comments setting is active and set to less than 2, and there is one nested comment max
+	if ( ( ! pageComments || perPage >= 2 ) && commentsDepth < 3 ) {
+		placeholderComments.push( {
+			commentId: -2,
+			children: [],
+		} );
+	}
+
+	// Add a third comment unless the break comments setting is active and set to less than 3, and there aren't nested comments
+	if ( ( ! pageComments || perPage >= 3 ) && commentsDepth < 2 ) {
+		placeholderComments.push( {
+			commentId: -3,
+			children: [],
+		} );
+	}
+
+	// In case that the value is set but larger than 3 we truncate it to 3.
+	return placeholderComments;
 };
 
 /**
@@ -114,12 +126,11 @@ function CommentTemplateInnerBlocks( {
 				: null }
 
 			{ /* To avoid flicker when switching active block contexts, a preview
-			is ALWAYS rendered and the preview for the active block is hidden.
-			This ensures that when switching the active block, the component is not
-			mounted again but rather it only toggles the `isHidden` prop.
-
-			The same strategy is used for preventing the flicker in the Post Template
-			block. */ }
+			 is ALWAYS rendered and the preview for the active block is hidden.
+			 This ensures that when switching the active block, the component is not
+			 mounted again but rather it only toggles the `isHidden` prop.
+			 The same strategy is used for preventing the flicker in the Post Template
+			 block. */ }
 			<MemoizedCommentTemplatePreview
 				blocks={ blocks }
 				commentId={ comment.commentId }
@@ -239,6 +250,7 @@ export default function CommentTemplateEdit( {
 		threadCommentsDepth,
 		threadComments,
 		commentsPerPage,
+		pageComments,
 	} = useSelect( ( select ) => {
 		const { getSettings } = select( blockEditorStore );
 		return getSettings().__experimentalDiscussionSettings;
@@ -282,6 +294,7 @@ export default function CommentTemplateEdit( {
 	if ( ! postId ) {
 		commentTree = getCommentsPlaceholder( {
 			perPage: commentsPerPage,
+			pageComments,
 			threadComments,
 			threadCommentsDepth,
 		} );

packages/block-library/src/comments-title/edit.js

@@ -11,11 +11,13 @@ import {
 	BlockControls,
 	useBlockProps,
 	InspectorControls,
+	store as blockEditorStore,
 } from '@wordpress/block-editor';
 import { __, _n, sprintf } from '@wordpress/i18n';
 import { useEntityProp } from '@wordpress/core-data';
 import { PanelBody, ToggleControl } from '@wordpress/components';
 import { useState, useEffect } from '@wordpress/element';
+import { useSelect } from '@wordpress/data';
 import apiFetch from '@wordpress/api-fetch';
 import { addQueryArgs } from '@wordpress/url';
 
@@ -39,9 +41,30 @@ export default function Edit( {
 		} ),
 	} );
 
+	const {
+		threadCommentsDepth,
+		threadComments,
+		commentsPerPage,
+		pageComments,
+	} = useSelect( ( select ) => {
+		const { getSettings } = select( blockEditorStore );
+		return getSettings().__experimentalDiscussionSettings;
+	} );
+
 	useEffect( () => {
 		if ( isSiteEditor ) {
-			setCommentsCount( 3 );
+			// Match the number of comments that will be shown in the comment-template/edit.js placeholder
+
+			const nestedCommentsNumber = threadComments
+				? Math.min( threadCommentsDepth, 3 ) - 1
+				: 0;
+			const topLevelCommentsNumber = pageComments ? commentsPerPage : 3;
+
+			const commentsNumber =
+				parseInt( nestedCommentsNumber ) +
+				parseInt( topLevelCommentsNumber );
+
+			setCommentsCount( Math.min( commentsNumber, 3 ) );
 			return;
 		}
 		const currentPostId = postId;