Add plugin system

README.md

@@ -126,6 +126,7 @@ features:
     provider: "plausible"
     id: "my-site.io"
 
+pluginsDir: "plugins"          # Folder for custom plugins
 plugins:
   - "analytics"                 # Load from plugins/
 ```
@@ -223,4 +224,43 @@ To make DocForge truly user-friendly, include these instructions in the starter
 - **Future**: PDF export plugin, AI-assisted search suggestions.
 - **Community**: MIT license; GitHub for issues.
 
+## Creating Custom Plugins
+
+Plugins are plain Node.js modules placed in the folder defined by `pluginsDir`.
+Each module can export hook functions which DocForge calls during the build:
+
+```js
+module.exports = {
+  // Modify markdown before frontmatter is parsed
+  async onParseMarkdown({ file, content }) {
+    return { content };
+  },
+  // Modify the final HTML of each page
+  async onPageRendered({ file, html }) {
+    return { html };
+  }
+};
+```
+
+Example `plugins/analytics.js`:
+
+```js
+module.exports = {
+  onPageRendered: async ({ html, file }) => {
+    const snippet = `\n<script>console.log('Page viewed: ${file}')</script>`;
+    return { html: html.replace('</body>', `${snippet}</body>`) };
+  }
+};
+```
+
+Enable it in `config.yaml`:
+
+```yaml
+pluginsDir: "plugins"
+plugins:
+  - "analytics"
+```
+
+Running `npm run build` will load the plugin and execute its hooks.
+
 This spec is complete and ready for implementation. Prototype core parsing first, then add features iteratively. Total est. dev time: 2-4 weeks for MVP.

plugins/analytics.js

@@ -0,0 +1,7 @@
+module.exports = {
+  onPageRendered: async ({ html, file }) => {
+    // Example: inject analytics script into each page
+    const snippet = '\n<script>console.log("Page viewed: ' + file + '")</script>';
+    return html.replace('</body>', `${snippet}</body>`);
+  }
+};

src/config/loadConfig.js

@@ -44,6 +44,7 @@ function loadConfig(configPath = path.join(process.cwd(), 'config.yaml')) {
       darkMode: false
     },
     features: {},
+    pluginsDir: 'plugins',
     plugins: []
   };
 

src/config/loadPlugins.js

@@ -0,0 +1,24 @@
+const path = require('path');
+const fs = require('fs');
+
+function loadPlugins(config) {
+  const dir = path.resolve(process.cwd(), config.pluginsDir || 'plugins');
+  const names = Array.isArray(config.plugins) ? config.plugins : [];
+  const plugins = [];
+  for (const name of names) {
+    const file = path.join(dir, name.endsWith('.js') ? name : `${name}.js`);
+    if (fs.existsSync(file)) {
+      try {
+        const mod = require(file);
+        plugins.push(mod);
+      } catch (e) {
+        console.error(`Failed to load plugin ${name}:`, e);
+      }
+    } else {
+      console.warn(`Plugin not found: ${file}`);
+    }
+  }
+  return plugins;
+}
+
+module.exports = loadPlugins;

src/generator/index.js

@@ -6,6 +6,7 @@ const Eleventy = require('@11ty/eleventy');
 const lunr = require('lunr');
 const { lexer } = require('marked');
 const loadConfig = require('../config/loadConfig');
+const loadPlugins = require('../config/loadPlugins');
 
 async function readDirRecursive(dir) {
   const entries = await fs.promises.readdir(dir, { withFileTypes: true });
@@ -55,6 +56,17 @@ function buildNav(pages) {
 
 async function generate({ contentDir = 'content', outputDir = '_site', configPath } = {}) {
   const config = loadConfig(configPath);
+  const plugins = loadPlugins(config);
+
+  async function runHook(name, data) {
+    for (const plugin of plugins) {
+      if (typeof plugin[name] === 'function') {
+        const res = await plugin[name](data);
+        if (res !== undefined) data = res;
+      }
+    }
+    return data;
+  }
   if (!fs.existsSync(contentDir)) {
     console.error(`Content directory not found: ${contentDir}`);
     return;
@@ -76,7 +88,9 @@ async function generate({ contentDir = 'content', outputDir = '_site', configPat
           continue; // skip unchanged
         }
       }
-      const raw = await fs.promises.readFile(file, 'utf8');
+      let raw = await fs.promises.readFile(file, 'utf8');
+      const mdObj = await runHook('onParseMarkdown', { file: rel, content: raw });
+      if (mdObj && mdObj.content) raw = mdObj.content;
       const parsed = matter(raw);
       const title = parsed.data.title || path.basename(rel, '.md');
       const tokens = lexer(parsed.content || '');
@@ -124,6 +138,16 @@ async function generate({ contentDir = 'content', outputDir = '_site', configPat
   };
   await elev.write();
 
+  for (const page of pages) {
+    const outPath = path.join(outputDir, page.file.replace(/\.md$/, '.html'));
+    if (fs.existsSync(outPath)) {
+      let html = await fs.promises.readFile(outPath, 'utf8');
+      const result = await runHook('onPageRendered', { file: page.file, html });
+      if (result && result.html) html = result.html;
+      await fs.promises.writeFile(outPath, html);
+    }
+  }
+
   for (const asset of assets) {
     const srcPath = path.join(contentDir, asset);
     const destPath = path.join(outputDir, asset);