feat: add pre-render hook

4 files changed, 28 insertions, 2 deletions

diff --git a/README.md b/README.md
index ecb8095..3b76736 100644
--- a/README.md
+++ b/README.md
@@ -57,3 +57,4 @@ This has a nice side-effect of basically having a *continuous delivery* for free
 ## TODO:
  - Openring support
  - Pre-render hooks
+ - RSS feed
diff --git a/src/config.ts b/src/config.ts
index 544d15c..ab0ec12 100644
--- a/src/config.ts
+++ b/src/config.ts
@@ -1,3 +1,4 @@
+import _ from 'lodash';
 import { BenzinConfig  } from './lib/types';
 import nginxAdapter from './lib/nginxAdapter';
 
@@ -11,6 +12,24 @@ const config: BenzinConfig = {
     emojiRoot: '/public/emoji',
     css: '/public/style.css?h=benzin-next-cdn',
   },
+  hooks: {
+    async preRender(path, data, adapter, cdn) {
+      if (path.length === 1 && path[0] === 'index') {
+        // Inject blog preview into home page
+        const blog = await adapter.getMarkdownSource(cdn, ['blog', 'index']);
+        const previewContent = blog
+        .split('\n')
+        .filter(line => line.startsWith('-'))
+        .slice(0, 4)
+        .join('\n');
+
+        const split = data.split('# Recent blog posts');
+        return [split[0], '# Recent blog posts\n', previewContent, split[1]].join('');
+      }
+
+      return data;
+    }
+  },
 };
 
 export default config;
diff --git a/src/lib/types.ts b/src/lib/types.ts
index ed2566f..bce6b36 100644
--- a/src/lib/types.ts
+++ b/src/lib/types.ts
@@ -18,4 +18,8 @@ export interface BenzinConfig {
     emojiRoot: string;
     css: string;
   }
+
+  hooks: {
+    preRender: (path: string[], data: string, adapter: Adapter, cdn: string) => Promise<string>;
+  }
 }
diff --git a/src/pages/[...path].tsx b/src/pages/[...path].tsx
index 9f55cf8..cf5db8c 100644
--- a/src/pages/[...path].tsx
+++ b/src/pages/[...path].tsx
@@ -29,12 +29,14 @@ export const getStaticProps = async (context: GetStaticPropsContext) => {
     : [context.params?.path]
   );
 
-  const markdownSource = await benzinConfig.adapter.getMarkdownSource(benzinConfig.CDN, path);
+  const originalSource = await benzinConfig.adapter.getMarkdownSource(benzinConfig.CDN, path);
+  const sourceWithHooks = await benzinConfig.hooks.preRender(path, originalSource, benzinConfig.adapter, benzinConfig.CDN);
+
   const emojiFileNames = await benzinConfig.adapter.getEmojiFileNames(benzinConfig.CDN, benzinConfig.paths.emojiRoot);
 
   return {
     props: {
-      markdownSource,
+      markdownSource: sourceWithHooks,
       emojiFileNames,
       path,
     }