introduce topCategoryLevel options

fix #25

Author: tchiotludo

README.md

@@ -148,3 +148,26 @@ module.exports = {
 
 [flexsearch-options]: https://github.com/nextapps-de/flexsearch#initialize-index
 [search-max-suggestions]: https://vuepress.vuejs.org/theme/default-theme-config.html#built-in-search
+
+
+
+### Top Category Level
+
+You can define an option `topCategoryLevel` in order to define what is the top page title that will be displayed on search Box.
+Default is `0` meaning "top-most" category.
+If you define a level that don't exist for this page, it fails back to 0.  
+
+```js
+// /docs/.vuepress/config.js
+module.exports = {
+  plugins: [
+    [
+      'fulltext-search',
+      {
+        // provide the contents of a JavaScript file
+        topCategoryLevel: 1
+      },
+    ],
+  ],
+}
+```

index.js

@@ -5,6 +5,9 @@ const _ = require('lodash')
 let customTitles = null
 
 module.exports = (options, ctx, globalCtx) => ({
+  define: {
+    FTS_TOP_CATEGORY_LEVEL: options.topCategoryLevel || 0,
+  },
   extendPageData($page) {
     try {
       const { html } = $page._context.markdown.render($page._strippedContent || '')
@@ -56,9 +59,9 @@ module.exports = (options, ctx, globalCtx) => ({
 
 function normalizeText(text) {
   return text
-    .toLowerCase()
-    .normalize('NFD')
-    .replace(/[\u0300-\u036f]/g, '')
+      .toLowerCase()
+      .normalize('NFD')
+      .replace(/[\u0300-\u036f]/g, '')
 }
 
 function getCustomTitles(globalCtx) {

services/flexsearchSvc.js

@@ -1,3 +1,5 @@
+/* global FTS_TOP_CATEGORY_LEVEL */
+
 import Flexsearch from 'flexsearch'
 // Use when flexSearch v0.7.0 will be available
 // import cyrillicCharset from 'flexsearch/dist/lang/cyrillic/default.min.js'
@@ -106,9 +108,19 @@ export default {
 }
 
 function getParentPageTitle(page) {
-  const pathParts = page.path.split('/')
+  const pathParts = _.drop(page.path.split('/'))
   let parentPagePath = '/'
-  if (pathParts[1]) parentPagePath = `/${pathParts[1]}/`
+
+  if (pathParts[FTS_TOP_CATEGORY_LEVEL]) {
+    const topCategoryPath = '/' + _.chunk(pathParts, FTS_TOP_CATEGORY_LEVEL + 1)[0].join('/') + '/'
+    if (pagesByPath[topCategoryPath]) {
+      parentPagePath = pagesByPath;
+    }
+  }
+
+  if (parentPagePath == '/' && pathParts[0]) {
+    parentPagePath = `/${pathParts[0]}/`
+  }
 
   const parentPage = pagesByPath[parentPagePath] || page
   return parentPage.title