feat: add pagination in tag posts (#201)

* feat: add pagination in tag posts

Implement pagination in tag posts. Refactor and extract pagination logic and pagination component.

Closes: #152

* fix: update breadcrumbs for updated tag pagination

src/components/Breadcrumbs.astro

@@ -10,6 +10,18 @@ const breadcrumbList = currentUrlPath.split("/").slice(1);
 // replace Posts with Posts (page number)
 breadcrumbList[0] === "posts" &&
   breadcrumbList.splice(0, 2, `Posts (page ${breadcrumbList[1] || 1})`);
+
+// if breadcrumb is Home > Tags > [tag] > [page] <etc>
+// replace [tag] > [page] with [tag] (page number)
+breadcrumbList[0] === "tags" &&
+  !isNaN(Number(breadcrumbList[2])) &&
+  breadcrumbList.splice(
+    1,
+    3,
+    `${breadcrumbList[1]} ${
+      Number(breadcrumbList[2]) === 1 ? "" : "(page " + breadcrumbList[2] + ")"
+    }`
+  );
 ---
 
 <nav class="breadcrumb" aria-label="breadcrumb">

src/components/Pagination.astro

@@ -0,0 +1,57 @@
+---
+import LinkButton from "./LinkButton.astro";
+
+export interface Props {
+  currentPage: number;
+  totalPages: number;
+  prevUrl: string;
+  nextUrl: string;
+}
+
+const { currentPage, totalPages, prevUrl, nextUrl } = Astro.props;
+
+const prev = currentPage > 1 ? "" : "disabled";
+const next = currentPage < totalPages ? "" : "disabled";
+---
+
+{
+  totalPages > 1 && (
+    <nav class="pagination-wrapper" aria-label="Pagination">
+      <LinkButton
+        disabled={prev === "disabled"}
+        href={prevUrl}
+        className={`mr-4 select-none ${prev}`}
+        ariaLabel="Previous"
+      >
+        <svg xmlns="http://www.w3.org/2000/svg" class={`${prev}-svg`}>
+          <path d="M12.707 17.293 8.414 13H18v-2H8.414l4.293-4.293-1.414-1.414L4.586 12l6.707 6.707z" />
+        </svg>
+        Prev
+      </LinkButton>
+      {currentPage} / {totalPages}
+      <LinkButton
+        disabled={next === "disabled"}
+        href={nextUrl}
+        className={`ml-4 select-none ${next}`}
+        ariaLabel="Next"
+      >
+        Next
+        <svg xmlns="http://www.w3.org/2000/svg" class={`${next}-svg`}>
+          <path d="m11.293 17.293 1.414 1.414L19.414 12l-6.707-6.707-1.414 1.414L15.586 11H6v2h9.586z" />
+        </svg>
+      </LinkButton>
+    </nav>
+  )
+}
+
+<style>
+  .pagination-wrapper {
+    @apply mb-8 mt-auto flex justify-center;
+  }
+  .disabled {
+    @apply pointer-events-none select-none opacity-50 hover:text-skin-base group-hover:fill-skin-base;
+  }
+  .disabled-svg {
+    @apply group-hover:!fill-skin-base;
+  }
+</style>

src/layouts/Posts.astro

@@ -1,23 +1,20 @@
 ---
-import { SITE } from "@config";
+import type { CollectionEntry } from "astro:content";
 import Layout from "@layouts/Layout.astro";
 import Main from "@layouts/Main.astro";
 import Header from "@components/Header.astro";
 import Footer from "@components/Footer.astro";
+import Pagination from "@components/Pagination.astro";
 import Card from "@components/Card";
-import LinkButton from "@components/LinkButton.astro";
-import type { CollectionEntry } from "astro:content";
+import { SITE } from "@config";
 
 export interface Props {
-  pageNum: number;
+  currentPage: number;
   totalPages: number;
-  posts: CollectionEntry<"blog">[];
+  paginatedPosts: CollectionEntry<"blog">[];
 }
 
-const { pageNum, totalPages, posts } = Astro.props;
-
-const prev = pageNum > 1 ? "" : "disabled";
-const next = pageNum < totalPages ? "" : "disabled";
+const { currentPage, totalPages, paginatedPosts } = Astro.props;
 ---
 
 <Layout title={`Posts | ${SITE.title}`}>
@@ -25,52 +22,19 @@ const next = pageNum < totalPages ? "" : "disabled";
   <Main pageTitle="Posts" pageDesc="All the articles I've posted.">
     <ul>
       {
-        posts.map(({ data, slug }) => (
+        paginatedPosts.map(({ data, slug }) => (
           <Card href={`/posts/${slug}`} frontmatter={data} />
         ))
       }
     </ul>
   </Main>
 
-  {
-    totalPages > 1 && (
-      <nav class="pagination-wrapper" aria-label="Pagination">
-        <LinkButton
-          disabled={prev === "disabled"}
-          href={`/posts${pageNum - 1 !== 1 ? "/" + (pageNum - 1) : ""}`}
-          className={`mr-4 select-none ${prev}`}
-          ariaLabel="Previous"
-        >
-          <svg xmlns="http://www.w3.org/2000/svg" class={`${prev}-svg`}>
-            <path d="M12.707 17.293 8.414 13H18v-2H8.414l4.293-4.293-1.414-1.414L4.586 12l6.707 6.707z" />
-          </svg>
-          Prev
-        </LinkButton>
-        <LinkButton
-          disabled={next === "disabled"}
-          href={`/posts/${pageNum + 1}`}
-          className={`ml-4 select-none ${next}`}
-          ariaLabel="Next"
-        >
-          Next
-          <svg xmlns="http://www.w3.org/2000/svg" class={`${next}-svg`}>
-            <path d="m11.293 17.293 1.414 1.414L19.414 12l-6.707-6.707-1.414 1.414L15.586 11H6v2h9.586z" />
-          </svg>
-        </LinkButton>
-      </nav>
-    )
-  }
+  <Pagination
+    {currentPage}
+    {totalPages}
+    prevUrl={`/posts${currentPage - 1 !== 1 ? "/" + (currentPage - 1) : ""}`}
+    nextUrl={`/posts/${currentPage + 1}`}
+  />
+
   <Footer noMarginTop={totalPages > 1} />
 </Layout>
-
-<style>
-  .pagination-wrapper {
-    @apply mb-8 mt-auto flex justify-center;
-  }
-  .disabled {
-    @apply pointer-events-none select-none opacity-50 hover:text-skin-base group-hover:fill-skin-base;
-  }
-  .disabled-svg {
-    @apply group-hover:!fill-skin-base;
-  }
-</style>

src/layouts/TagPosts.astro

@@ -0,0 +1,49 @@
+---
+import { type CollectionEntry } from "astro:content";
+import Layout from "@layouts/Layout.astro";
+import Main from "@layouts/Main.astro";
+import Header from "@components/Header.astro";
+import Footer from "@components/Footer.astro";
+import Card from "@components/Card";
+import Pagination from "@components/Pagination.astro";
+import { SITE } from "@config";
+
+export interface Props {
+  currentPage: number;
+  totalPages: number;
+  paginatedPosts: CollectionEntry<"blog">[];
+  tag: string;
+  tagName: string;
+}
+
+const { currentPage, totalPages, paginatedPosts, tag, tagName } = Astro.props;
+---
+
+<Layout title={`Tag: ${tagName} | ${SITE.title}`}>
+  <Header activeNav="tags" />
+  <Main
+    pageTitle={[`Tag:`, `${tagName}`]}
+    titleTransition={tag}
+    pageDesc={`All the articles with the tag "${tagName}".`}
+  >
+    <h1 slot="title" transition:name={tag}>{`Tag:${tag}`}</h1>
+    <ul>
+      {
+        paginatedPosts.map(({ data, slug }) => (
+          <Card href={`/posts/${slug}`} frontmatter={data} />
+        ))
+      }
+    </ul>
+  </Main>
+
+  <Pagination
+    {currentPage}
+    {totalPages}
+    prevUrl={`/tags/${tag}${
+      currentPage - 1 !== 1 ? "/" + (currentPage - 1) : ""
+    }`}
+    nextUrl={`/tags/${tag}/${currentPage + 1}`}
+  />
+
+  <Footer noMarginTop={totalPages > 1} />
+</Layout>

src/pages/posts/[slug]/index.astro

@@ -4,7 +4,7 @@ import Posts from "@layouts/Posts.astro";
 import PostDetails from "@layouts/PostDetails.astro";
 import getSortedPosts from "@utils/getSortedPosts";
 import getPageNumbers from "@utils/getPageNumbers";
-import { SITE } from "@config";
+import getPagination from "@utils/getPagination";
 
 export interface Props {
   post: CollectionEntry<"blog">;
@@ -32,26 +32,10 @@ const posts = await getCollection("blog");
 
 const sortedPosts = getSortedPosts(posts);
 
-const totalPages = getPageNumbers(sortedPosts.length);
-
-const currentPage =
-  slug && !isNaN(Number(slug)) && totalPages.includes(Number(slug))
-    ? Number(slug)
-    : 0;
-const lastPost = currentPage * SITE.postPerPage;
-const startPost = lastPost - SITE.postPerPage;
-
-const paginatedPosts = sortedPosts.slice(startPost, lastPost);
+const pagination = getPagination({
+  posts: sortedPosts,
+  page: slug,
+});
 ---
 
-{
-  post ? (
-    <PostDetails post={post} />
-  ) : (
-    <Posts
-      posts={paginatedPosts}
-      pageNum={currentPage}
-      totalPages={totalPages.length}
-    />
-  )
-}
+{post ? <PostDetails post={post} /> : <Posts {...pagination} />}

src/pages/posts/index.astro

@@ -1,18 +1,18 @@
 ---
-import { SITE } from "@config";
+import { getCollection } from "astro:content";
 import Posts from "@layouts/Posts.astro";
 import getSortedPosts from "@utils/getSortedPosts";
-import getPageNumbers from "@utils/getPageNumbers";
-
-import { getCollection } from "astro:content";
+import getPagination from "@utils/getPagination";
 
 const posts = await getCollection("blog");
 
 const sortedPosts = getSortedPosts(posts);
 
-const totalPages = getPageNumbers(sortedPosts.length);
-
-const paginatedPosts = sortedPosts.slice(0, SITE.postPerPage);
+const pagination = getPagination({
+  posts: sortedPosts,
+  page: 1,
+  isIndex: true,
+});
 ---
 
-<Posts posts={paginatedPosts} pageNum={1} totalPages={totalPages.length} />
+<Posts {...pagination} />

src/pages/tags/[tag].astro

@@ -1,58 +0,0 @@
----
-import { type CollectionEntry, getCollection } from "astro:content";
-import Layout from "@layouts/Layout.astro";
-import Main from "@layouts/Main.astro";
-import Header from "@components/Header.astro";
-import Footer from "@components/Footer.astro";
-import Card from "@components/Card";
-import getUniqueTags from "@utils/getUniqueTags";
-import getPostsByTag from "@utils/getPostsByTag";
-import { SITE } from "@config";
-import getSortedPosts from "@utils/getSortedPosts";
-
-export interface Props {
-  post: CollectionEntry<"blog">;
-  tag: string;
-  tagName: string;
-}
-
-export async function getStaticPaths() {
-  const posts = await getCollection("blog");
-
-  const tags = getUniqueTags(posts);
-
-  return tags.map(({ tag, tagName }) => {
-    return {
-      params: { tag },
-      props: { tag, tagName },
-    };
-  });
-}
-
-const { tag, tagName } = Astro.props;
-
-const posts = await getCollection("blog", ({ data }) => !data.draft);
-
-const tagPosts = getPostsByTag(posts, tag);
-
-const sortTagsPost = getSortedPosts(tagPosts);
----
-
-<Layout title={`Tag: ${tagName} | ${SITE.title}`}>
-  <Header activeNav="tags" />
-  <Main
-    pageTitle={[`Tag:`, `${tagName}`]}
-    titleTransition={tag}
-    pageDesc={`All the articles with the tag "${tagName}".`}
-  >
-    <h1 slot="title" transition:name={tag}>{`Tag:${tag}`}</h1>
-    <ul>
-      {
-        sortTagsPost.map(({ data, slug }) => (
-          <Card href={`/posts/${slug}`} frontmatter={data} />
-        ))
-      }
-    </ul>
-  </Main>
-  <Footer />
-</Layout>

src/pages/tags/[tag]/[page].astro

@@ -0,0 +1,44 @@
+---
+import { type CollectionEntry, getCollection } from "astro:content";
+import TagPosts from "@layouts/TagPosts.astro";
+import getUniqueTags from "@utils/getUniqueTags";
+import getPostsByTag from "@utils/getPostsByTag";
+import getPageNumbers from "@utils/getPageNumbers";
+import getPagination from "@utils/getPagination";
+
+export interface Props {
+  post: CollectionEntry<"blog">;
+  tag: string;
+  tagName: string;
+}
+
+export async function getStaticPaths() {
+  const posts = await getCollection("blog");
+
+  const tags = getUniqueTags(posts);
+
+  return tags.flatMap(({ tag, tagName }) => {
+    const tagPosts = getPostsByTag(posts, tag);
+    const totalPages = getPageNumbers(tagPosts.length);
+
+    return totalPages.map(page => ({
+      params: { tag, page },
+      props: { tag, tagName },
+    }));
+  });
+}
+
+const { page } = Astro.params;
+const { tag, tagName } = Astro.props;
+
+const posts = await getCollection("blog", ({ data }) => !data.draft);
+
+const postsByTag = getPostsByTag(posts, tag);
+
+const pagination = getPagination({
+  posts: postsByTag,
+  page,
+});
+---
+
+<TagPosts {...pagination} {tag} {tagName} />

src/pages/tags/[tag]/index.astro

@@ -0,0 +1,32 @@
+---
+import { getCollection } from "astro:content";
+import TagPosts from "@layouts/TagPosts.astro";
+import getPostsByTag from "@utils/getPostsByTag";
+import getPagination from "@utils/getPagination";
+import getUniqueTags from "@utils/getUniqueTags";
+
+export async function getStaticPaths() {
+  const posts = await getCollection("blog");
+
+  const tags = getUniqueTags(posts);
+
+  return tags.map(({ tag, tagName }) => {
+    return {
+      params: { tag },
+      props: { tag, tagName, posts },
+    };
+  });
+}
+
+const { tag, tagName, posts } = Astro.props;
+
+const postsByTag = getPostsByTag(posts, tag);
+
+const pagination = getPagination({
+  posts: postsByTag,
+  page: 1,
+  isIndex: true,
+});
+---
+
+<TagPosts {...pagination} {tag} {tagName} />

src/utils/getPagination.ts

@@ -0,0 +1,35 @@
+import { SITE } from "@config";
+import getPageNumbers from "./getPageNumbers";
+
+interface GetPaginationProps<T> {
+  posts: T;
+  page: string | number;
+  isIndex?: boolean;
+}
+
+const getPagination = <T>({
+  posts,
+  page,
+  isIndex = false,
+}: GetPaginationProps<T[]>) => {
+  const totalPagesArray = getPageNumbers(posts.length);
+  const totalPages = totalPagesArray.length;
+
+  const currentPage = isIndex
+    ? 1
+    : page && !isNaN(Number(page)) && totalPagesArray.includes(Number(page))
+      ? Number(page)
+      : 0;
+
+  const lastPost = isIndex ? SITE.postPerPage : currentPage * SITE.postPerPage;
+  const startPost = isIndex ? 0 : lastPost - SITE.postPerPage;
+  const paginatedPosts = posts.slice(startPost, lastPost);
+
+  return {
+    totalPages,
+    currentPage,
+    paginatedPosts,
+  };
+};
+
+export default getPagination;

src/utils/getPostsByTag.ts

@@ -1,7 +1,10 @@
-import { slugifyAll } from "./slugify";
 import type { CollectionEntry } from "astro:content";
+import getSortedPosts from "./getSortedPosts";
+import { slugifyAll } from "./slugify";
 
 const getPostsByTag = (posts: CollectionEntry<"blog">[], tag: string) =>
-  posts.filter(post => slugifyAll(post.data.tags).includes(tag));
+  getSortedPosts(
+    posts.filter(post => slugifyAll(post.data.tags).includes(tag))
+  );
 
 export default getPostsByTag;