add on demand revalidation

Author: gregrickaby

pages/api/wordpress/revalidate.js

@@ -0,0 +1,36 @@
+/**
+ * On-demand post revalidation.
+ *
+ * @see https://nextjs.org/docs/basic-features/data-fetching/incremental-static-regeneration#using-on-demand-revalidation
+ * @author WebDevStudios
+ * @param {object} req Instance of http.IncomingMessage.
+ * @param {object} res Instance of http.ServerResponse.
+ */
+export default async function revalidate(req, res) {
+  // Check for a valid secret.
+  if (req.body.secret !== process.env.WORDPRESS_PREVIEW_SECRET) {
+    return res.status(401).json({
+      message:
+        'Invalid secret. Please check your .env file or the POST request.'
+    })
+  }
+
+  // Check for a valid post slug.
+  if (!req.body.slug) {
+    return res.status(400).json({
+      message: 'A slug is required to revalidate the cache.'
+    })
+  }
+
+  // Try to revalidate the post cache.
+  try {
+    await res.unstable_revalidate(req.body.slug)
+    return res.status(200).json({
+      message: `Success! The cache for ${req.body.slug} was successfully revalidated.`
+    })
+  } catch (err) {
+    return res.status(500).json({
+      message: err.message
+    })
+  }
+}