From 9626ab8dda63b3ec49a1ce6a8d4dcb995f132051 Mon Sep 17 00:00:00 2001
From: Billyyyyy3320 <newsbielt703@gmail.com>
Date: Fri, 17 Jan 2020 00:05:41 +0800
Subject: [PATCH] feat: use summary as meta description

---
 docs/config/README.md       |  2 +-
 example/.vuepress/config.js |  2 +-
 index.js                    | 33 ++++++++++++++++++---------------
 3 files changed, 20 insertions(+), 17 deletions(-)

diff --git a/docs/config/README.md b/docs/config/README.md
index 0e83e6e..b7c9f32 100644
--- a/docs/config/README.md
+++ b/docs/config/README.md
@@ -361,7 +361,7 @@ Since many features are powered by the plugin, we suggest you to read the [docum
 - Type: `boolean`
 - Default: `true`
 
-Whether to extract summary from source markdowns. You can write summary manually by [front matter](./front-matter.md#summary).
+Whether to automatically extract summary from source markdowns. You can write summary manually by [front matter](./front-matter.md#summary). Summary is not only for displaying but also page meta description. 
 
 
 ## summaryLength
diff --git a/example/.vuepress/config.js b/example/.vuepress/config.js
index 7a3e44b..6d3d412 100755
--- a/example/.vuepress/config.js
+++ b/example/.vuepress/config.js
@@ -177,7 +177,7 @@ module.exports = {
      * Ref: https://vuepress-theme-blog.ulivz.com/#summary
      */
 
-    // summary:false,
+    summary:false,
 
     /**
      * Ref: https://vuepress-theme-blog.ulivz.com/#summarylength
diff --git a/index.js b/index.js
index 5a3891b..2c31d7d 100644
--- a/index.js
+++ b/index.js
@@ -112,25 +112,28 @@ module.exports = themeConfig => {
     alias: {
       fonts: path.resolve(__dirname, 'fonts'),
     },
-  }
-
-  /**
-   * Generate summary.
-   */
-  if (themeConfig.summary) {
-    config.extendPageData = function(pageCtx) {
+    /**
+     * Generate summary.
+     */
+    extendPageData(pageCtx) {
       const strippedContent = pageCtx._strippedContent
       if (!strippedContent) {
         return
       }
-      pageCtx.summary =
-        removeMd(
-          strippedContent
-            .trim()
-            .replace(/^#+\s+(.*)/, '')
-            .slice(0, themeConfig.summaryLength)
-        ) + ' ...'
-    }
+      if (themeConfig.summary) {
+        pageCtx.summary =
+          removeMd(
+            strippedContent
+              .trim()
+              .replace(/^#+\s+(.*)/, '')
+              .slice(0, themeConfig.summaryLength)
+          ) + ' ...'
+        pageCtx.frontmatter.description = pageCtx.summary
+      }
+      if (pageCtx.frontmatter.summary) {
+        pageCtx.frontmatter.description = pageCtx.frontmatter.summary
+      }
+    },
   }
 
   return config