fix: add an option to disable dynamic OG image generation (#476)

* fix: add an option to disable dynamic OG image generation

Add new `dynamicOgImage` option in the `SITE` object inside 
`src/config.ts` file to disable auto og-image generation during build.

Resolves #428

* docs: update guides for `SITE.dynamicOgImage` option

src/config.ts

@@ -16,4 +16,5 @@ export const SITE = {
     text: "Suggest Changes",
     appendFilePath: true,
   },
+  dynamicOgImage: true,
 } as const;

src/data/blog/dynamic-og-images.md

@@ -1,6 +1,7 @@
 ---
 author: Sat Naing
 pubDatetime: 2022-12-28T04:59:04.866Z
+modDatetime: 2025-03-12T13:39:20.763Z
 title: Dynamic OG image generation in AstroPaper blog posts
 slug: dynamic-og-image-generation-in-astropaper-blog-posts
 featured: false
@@ -80,6 +81,14 @@ async function loadGoogleFonts(
 
 > Check out [this PR](https://github.com/satnaing/astro-paper/pull/318) for more info.
 
+## Trade-off
+
+While this is a nice feature to have, there's a trade-off. Each OG image takes roughly one second to generate. This might not be noticeable at first, but as the number of blog posts grows, you might want to disable this feature. Since every OG image takes time to generate, having many of them will increase the build time linearly.
+
+For example: If one OG image takes one second to generate, then 60 images will take around one minute, and 600 images will take approximately 10 minutes. This can significantly impact build times as your content scales.
+
+Related issue: [#428](https://github.com/satnaing/astro-paper/issues/428)
+
 ## Limitations
 
 At the time of writing this, [Satori](https://github.com/vercel/satori) is fairly new and has not reached major release yet. So, there are still some limitations to this dynamic OG image feature.

src/data/blog/how-to-configure-astropaper-theme.md

@@ -1,7 +1,7 @@
 ---
 author: Sat Naing
 pubDatetime: 2022-09-23T04:58:53Z
-modDatetime: 2025-03-07T14:01:26.494Z
+modDatetime: 2025-03-12T13:39:39.057Z
 title: How to configure AstroPaper theme
 slug: how-to-configure-astropaper-theme
 featured: true
@@ -42,13 +42,14 @@ export const SITE = {
     text: "Suggest Changes",
     appendFilePath: true,
   },
+  dynamicOgImage: true, // enable automatic dynamic og-image generation
 } as const;
 ```
 
 Here are SITE configuration options
 
 | Options               | Description                                                                                                                                                                                                                                                                                                                                                                                                                       |
-| --------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| --------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
 | `website`             | Your deployed website URL                                                                                                                                                                                                                                                                                                                                                                                                         |
 | `author`              | Your name                                                                                                                                                                                                                                                                                                                                                                                                                         |
 | `profile`             | Your personal/portfolio website URL which is used for better SEO. Put `null` or empty string `""` if you don't have any.                                                                                                                                                                                                                                                                                                          |
@@ -62,6 +63,7 @@ Here are SITE configuration options
 | `showArchives`        | Determines whether to display the `Archives` menu (positioned between the `About` and `Search` menus) and its corresponding page on the site. This option is set to `true` by default.                                                                                                                                                                                                                                            |
 | `showBackButton`      | Determines whether to display the `Go back` button in each blog post.                                                                                                                                                                                                                                                                                                                                                             |
 | `editPost`            | This option allows users to suggest changes to a blog post by providing an edit link under blog post titles. This feature can be disabled by removing it from the `SITE` config. You can also set `appendFilePath` to `true` to automatically append the file path of the post to the url, directing users to the specific post they wish to edit.                                                                                |
+| `dynamicOgImage`      | This option controls whether to [generate dynamic og-image](https://astro-paper.pages.dev/posts/dynamic-og-image-generation-in-astropaper-blog-posts/) if no `ogImage` is specified in the blog post frontmatter. If you have many blog posts, you might want to disable this feature. See the [trade-off](https://astro-paper.pages.dev/posts/dynamic-og-image-generation-in-astropaper-blog-posts/#trade-off) for more details. |
 
 ## Configuring locale
 

src/layouts/Layout.astro

@@ -23,14 +23,14 @@ const {
   author = SITE.author,
   profile = SITE.profile,
   description = SITE.desc,
-  ogImage = SITE.ogImage,
+  ogImage = SITE.ogImage ? `/${SITE.ogImage}` : "/og.png",
   canonicalURL = new URL(Astro.url.pathname, Astro.url),
   pubDatetime,
   modDatetime,
   scrollSmooth = false,
 } = Astro.props;
 
-const socialImageURL = new URL(ogImage ?? SITE.ogImage ?? "og.png", Astro.url);
+const socialImageURL = new URL(ogImage, Astro.url);
 
 const structuredData = {
   "@context": "https://schema.org",

src/layouts/PostDetails.astro

@@ -24,7 +24,7 @@ const {
   title,
   author,
   description,
-  ogImage,
+  ogImage: initOgImage,
   canonicalURL,
   pubDatetime,
   modDatetime,
@@ -34,11 +34,24 @@ const {
 
 const { Content } = await render(post);
 
-const ogImageUrl = typeof ogImage === "string" ? ogImage : ogImage?.src;
+let ogImageUrl: string | undefined;
-const ogUrl = new URL(
+
-  ogImageUrl ?? `/posts/${slugifyStr(title)}/index.png`,
+// Determine OG image source
-  Astro.url.origin
+if (typeof initOgImage === "string") {
-).href;
+  ogImageUrl = initOgImage; // Remote OG image (absolute URL)
+} else if (initOgImage?.src) {
+  ogImageUrl = initOgImage.src; // Local asset
+}
+
+// Use dynamic OG image if enabled and no remote|local ogImage
+if (!ogImageUrl && SITE.dynamicOgImage) {
+  ogImageUrl = `/posts/${slugifyStr(title)}/index.png`;
+}
+
+// Resolve OG image URL (or fallback to SITE.ogImage / default `og.png`)
+const ogImage = ogImageUrl
+  ? new URL(ogImageUrl, Astro.url.origin).href
+  : undefined;
 
 const layoutProps = {
   title: `${title} | ${SITE.title}`,
@@ -47,7 +60,7 @@ const layoutProps = {
   pubDatetime,
   modDatetime,
   canonicalURL,
-  ogImage: ogUrl,
+  ogImage,
   scrollSmooth: true,
 };
 

src/pages/posts/[slug]/index.png.ts

@@ -2,8 +2,13 @@ import type { APIRoute } from "astro";
 import { getCollection, type CollectionEntry } from "astro:content";
 import { generateOgImageForPost } from "@/utils/generateOgImages";
 import { slugifyStr } from "@/utils/slugify";
+import { SITE } from "@/config";
 
 export async function getStaticPaths() {
+  if (!SITE.dynamicOgImage) {
+    return [];
+  }
+
   const posts = await getCollection("blog").then(p =>
     p.filter(({ data }) => !data.draft && !data.ogImage)
   );
@@ -14,7 +19,18 @@ export async function getStaticPaths() {
   }));
 }
 
-export const GET: APIRoute = async ({ props }) =>
+export const GET: APIRoute = async ({ props }) => {
-  new Response(await generateOgImageForPost(props as CollectionEntry<"blog">), {
+  if (!SITE.dynamicOgImage) {
-    headers: { "Content-Type": "image/png" },
+    return new Response(null, {
+      status: 404,
+      statusText: "Not found",
     });
+  }
+
+  return new Response(
+    await generateOgImageForPost(props as CollectionEntry<"blog">),
+    {
+      headers: { "Content-Type": "image/png" },
+    }
+  );
+};