From 03c5ba6791dcf7e097f14246af61d107cdadaeff Mon Sep 17 00:00:00 2001
From: Armand Philippot <git@armandphilippot.com>
Date: Fri, 14 Jan 2022 16:28:14 +0100
Subject: chore: improve load more button accessibility

On click, the focus should be moved to the last post in the list
instead of keeping it on load more button. It helps to keep a
consistent navigation for keyboard users for example.
---
 src/components/PostsList/PostsList.module.scss |  5 ++-
 src/components/PostsList/PostsList.tsx         | 52 ++++++++++++++++++--------
 src/pages/blog/index.tsx                       | 14 ++++++-
 src/pages/recherche/index.tsx                  | 15 ++++++--
 4 files changed, 65 insertions(+), 21 deletions(-)

(limited to 'src')

diff --git a/src/components/PostsList/PostsList.module.scss b/src/components/PostsList/PostsList.module.scss
index c0f8062..6c3f93e 100644
--- a/src/components/PostsList/PostsList.module.scss
+++ b/src/components/PostsList/PostsList.module.scss
@@ -33,9 +33,12 @@
 }
 
 li.item {
-  margin: 0 0 var(--spacing-md) 0;
   border-bottom: fun.convert-px(1) solid var(--color-border-light);
 
+  &:not(:last-of-type) {
+    margin: 0 0 var(--spacing-md) 0;
+  }
+
   &:first-of-type {
     margin-top: var(--spacing-sm);
 
diff --git a/src/components/PostsList/PostsList.tsx b/src/components/PostsList/PostsList.tsx
index f401d83..df9dfe4 100644
--- a/src/components/PostsList/PostsList.tsx
+++ b/src/components/PostsList/PostsList.tsx
@@ -2,22 +2,31 @@ import { t } from '@lingui/macro';
 import { PostsList as PostsListData } from '@ts/types/blog';
 import styles from './PostsList.module.scss';
 import PostPreview from '@components/PostPreview/PostPreview';
-import { Fragment } from 'react';
+import { ForwardedRef, forwardRef, Fragment } from 'react';
 import { sortPostsByYear } from '@utils/helpers/sort';
 
-const PostsList = ({
-  data,
-  showYears,
-}: {
-  data: PostsListData[];
-  showYears: boolean;
-}) => {
+const PostsList = (
+  {
+    data,
+    showYears,
+  }: {
+    data: PostsListData[];
+    showYears: boolean;
+  },
+  ref: ForwardedRef<HTMLSpanElement>
+) => {
   const titleLevel = showYears ? 3 : 2;
 
   const getPostsListByYear = () => {
     const posts = sortPostsByYear(data);
     const years = Object.keys(posts).reverse();
 
+    const getLastPostId = () => {
+      const oldestYear = Object.keys(posts)[0];
+      const lastPost = posts[oldestYear][posts[oldestYear].length - 1];
+      return lastPost.id;
+    };
+
     return years.map((year) => {
       return (
         <section key={year} className={styles.section}>
@@ -29,10 +38,14 @@ const PostsList = ({
           )}
           <ol className={styles.list}>
             {posts[year].map((post) => {
+              const isLastPost = post.id === getLastPostId();
               return (
-                <li key={post.id} className={styles.item}>
-                  <PostPreview post={post} titleLevel={titleLevel} />
-                </li>
+                <Fragment key={post.id}>
+                  <li className={styles.item}>
+                    <PostPreview post={post} titleLevel={titleLevel} />
+                  </li>
+                  {isLastPost && <span ref={ref} tabIndex={-1} />}
+                </Fragment>
               );
             })}
           </ol>
@@ -43,6 +56,11 @@ const PostsList = ({
 
   const getPostsList = () => {
     return data.map((page) => {
+      const getLastPostId = () => {
+        const lastPost = page.posts[page.posts.length - 1];
+        return lastPost.id;
+      };
+
       if (page.posts.length === 0) {
         return <p key="no-result">{t`No results found.`}</p>;
       } else {
@@ -50,10 +68,14 @@ const PostsList = ({
           <Fragment key={page.pageInfo.endCursor}>
             <ol className={styles.list}>
               {page.posts.map((post) => {
+                const isLastPost = post.id === getLastPostId();
                 return (
-                  <li key={post.id} className={styles.item}>
-                    <PostPreview post={post} titleLevel={titleLevel} />
-                  </li>
+                  <Fragment key={post.id}>
+                    <li key={post.id} className={styles.item}>
+                      <PostPreview post={post} titleLevel={titleLevel} />
+                    </li>
+                    {isLastPost && <span ref={ref} tabIndex={-1} />}
+                  </Fragment>
                 );
               })}
             </ol>
@@ -66,4 +88,4 @@ const PostsList = ({
   return <div>{showYears ? getPostsListByYear() : getPostsList()}</div>;
 };
 
-export default PostsList;
+export default forwardRef(PostsList);
diff --git a/src/pages/blog/index.tsx b/src/pages/blog/index.tsx
index faadd6f..e0d35cd 100644
--- a/src/pages/blog/index.tsx
+++ b/src/pages/blog/index.tsx
@@ -15,8 +15,11 @@ import PostHeader from '@components/PostHeader/PostHeader';
 import { ThematicsList, TopicsList } from '@components/Widget';
 import Sidebar from '@components/Sidebar/Sidebar';
 import styles from '@styles/pages/Page.module.scss';
+import { useRef } from 'react';
 
 const Blog: NextPageWithLayout<BlogPageProps> = ({ fallback }) => {
+  const lastPostRef = useRef<HTMLSpanElement>(null);
+
   const getKey = (pageIndex: number, previousData: PostsListData) => {
     if (previousData && !previousData.posts) return null;
 
@@ -44,6 +47,13 @@ const Blog: NextPageWithLayout<BlogPageProps> = ({ fallback }) => {
 
   const hasNextPage = data && data[data.length - 1].pageInfo.hasNextPage;
 
+  const loadMorePosts = () => {
+    if (lastPostRef.current) {
+      lastPostRef.current.focus();
+    }
+    setSize(size + 1);
+  };
+
   return (
     <>
       <Head>
@@ -55,11 +65,11 @@ const Blog: NextPageWithLayout<BlogPageProps> = ({ fallback }) => {
       >
         <PostHeader title={t`Blog`} />
         <div className={styles.body}>
-          <PostsList data={data} showYears={true} />
+          <PostsList ref={lastPostRef} data={data} showYears={true} />
           {hasNextPage && (
             <Button
               isDisabled={isLoadingMore}
-              clickHandler={() => setSize(size + 1)}
+              clickHandler={loadMorePosts}
               position="center"
             >{t`Load more?`}</Button>
           )}
diff --git a/src/pages/recherche/index.tsx b/src/pages/recherche/index.tsx
index c8a7b9b..57f40e2 100644
--- a/src/pages/recherche/index.tsx
+++ b/src/pages/recherche/index.tsx
@@ -11,7 +11,7 @@ import { loadTranslation } from '@utils/helpers/i18n';
 import { GetStaticProps } from 'next';
 import Head from 'next/head';
 import { useRouter } from 'next/router';
-import { useEffect, useState } from 'react';
+import { useEffect, useRef, useState } from 'react';
 import useSWRInfinite from 'swr/infinite';
 import Sidebar from '@components/Sidebar/Sidebar';
 import { ThematicsList, TopicsList } from '@components/Widget';
@@ -20,6 +20,7 @@ import styles from '@styles/pages/Page.module.scss';
 const Search: NextPageWithLayout = () => {
   const [query, setQuery] = useState('');
   const router = useRouter();
+  const lastPostRef = useRef<HTMLSpanElement>(null);
 
   useEffect(() => {
     if (!router.isReady) return;
@@ -69,6 +70,13 @@ const Search: NextPageWithLayout = () => {
         message: 'Search',
       });
 
+  const loadMorePosts = () => {
+    if (lastPostRef.current) {
+      lastPostRef.current.focus();
+    }
+    setSize(size + 1);
+  };
+
   return (
     <>
       <Head>
@@ -80,11 +88,12 @@ const Search: NextPageWithLayout = () => {
       >
         <PostHeader title={title} />
         <div className={styles.body}>
-          <PostsList data={data} showYears={false} />
+          <PostsList ref={lastPostRef} data={data} showYears={false} />
           {hasNextPage && (
             <Button
               isDisabled={isLoadingMore}
-              clickHandler={() => setSize(size + 1)}
+              clickHandler={loadMorePosts}
+              position="center"
             >{t`Load more?`}</Button>
           )}
         </div>
-- 
cgit v1.2.3