feat(search): 添加 DocSearch 搜索支持

- 在 _config.yml 中增加 DocSearch 相关配置选项
- 在 search/index.pug 中添加 DocSearch 搜索的条件包含
- 在 plugins.yml 中添加 DocSearch 所需的 CSS 和 JS 文件
- 在 merge_config.js 中添加 DocSearch 配置项的默认值

_config.yml

@@ -869,17 +869,27 @@ giscus:
 # Search
 search:
   enable: false
-  # type: 使用的搜索引擎 / search engine
-  type: local # local / algolia
+  type: # local / algolia / docsearch
   tags:
     # - Solitude
     # - Hexo
+  # Algolia
   algolia:
     # hits:
     #   per_page: 6
+
+  # Local search
   local:
     preload: false
     CDN: # url: search.xml
+
+  # DocSearch
+  # https://docsearch.algolia.com/
+  docsearch: 
+    appId: 
+    apiKey: 
+    indexName: 
+    option: 
 # --------------------------- end ---------------------------
 
 # --------------------------- start ---------------------------

layout/includes/widgets/third-party/search/docsearch.pug

@@ -0,0 +1,26 @@
+- const { placeholder, docsearch: { appId, apiKey, indexName, option } } = theme.search
+
+.docsearch-wrap
+  #docsearch(style="display:none")
+  script(src=url_for(theme.cdn.docsearch_js))
+  script.
+    (() => {
+      docsearch(Object.assign({
+        appId: '!{appId}',
+        apiKey: '!{apiKey}',
+        indexName: '!{indexName}',
+        container: '#docsearch',
+        placeholder: '!{ placeholder || _p("search.input_placeholder")}',
+      }, !{JSON.stringify(option)}))
+
+      const handleClick = () => {
+        document.querySelector('.DocSearch-Button').click()
+      }
+
+      const searchClickFn = () => {
+        utils.addEventListenerPjax(document.querySelector('#search-button > .search'), 'click', handleClick)
+      }
+
+      searchClickFn()
+      window.addEventListener('pjax:complete', searchClickFn)
+    })()

layout/includes/widgets/third-party/search/index.pug

@@ -5,4 +5,7 @@ if theme.search.enable
             script(src=url_for(theme.cdn.algolia_js))
         when 'local'
             include local-search
-            script(src=url_for(theme.cdn.local_search))
+            script(src=url_for(theme.cdn.local_search))
+        when 'docsearch'
+            include docsearch
+            link(rel="stylesheet" href=url_for(theme.cdn.docsearch_css))

plugins.yml

@@ -6,6 +6,16 @@ instantsearch:
   name: instantsearch.js
   file: dist/instantsearch.production.min.js
   version: 4.75.6
+docsearch_css:
+  name: '@docsearch/css'
+  other_name: docsearch-css
+  file: dist/style.css
+  version: 3.8.2
+docsearch_js:
+  name: '@docsearch/js'
+  other_name: docsearch-js
+  file: dist/umd/index.js
+  version: 3.8.2
 pjax:
   name: pjax
   file: pjax.min.js

scripts/event/merge_config.js

@@ -246,6 +246,12 @@ hexo.extend.filter.register('before_generate', () => {
       local: {
         preload: false,
         CDN: null,
+      },
+      docsearch: {
+        appId: null,
+        apiKey: null,
+        indexName: null,
+        option: null
       }
     },
     rightside: {