Integrated FlexSearch.js and removed DuckDuckGo search.

assets/js/search.js

@@ -0,0 +1,75 @@
+/**
+ * @file
+ * A JavaScript file for flexsearch.
+ */
+
+(function () {
+
+  'use strict';
+
+  const flexSearch = new FlexSearch({
+    doc: {
+      id: 'id',
+      field: ['title','tags','content','date'],
+      store: ['title','summary','date','permalink']
+    }
+  });
+
+  function showResults(items) {
+    const template = document.querySelector('template').content;
+    const fragment = document.createDocumentFragment();
+
+    const results = document.querySelector('.search-results');
+    results.textContent = '';
+
+    for (const item of items) {
+      const result = template.cloneNode(true);
+      const a = result.querySelector('a');
+      const time = result.querySelector('time');
+      const content = result.querySelector('.content');
+      a.innerHTML = item.title;
+      a.href = item.permalink;
+      time.innerText = item.date;
+      content.innerHTML = item.summary;
+      fragment.appendChild(result);
+    }
+    results.appendChild(fragment);
+  }
+
+  function doSearch () {
+    const query = document.querySelector('.search-text').value.trim();
+    const results = flexSearch.search({
+      query: query,
+      limit: {{ .Site.Params.searchLimit | default 20 }}
+    });
+    showResults(results);
+  }
+
+  function enableUI () {
+    const searchform = document.querySelector('.search-form');
+    searchform.addEventListener('submit', function (e) {
+      e.preventDefault();
+      doSearch();
+    })
+    searchform.addEventListener('keyup', function () {
+      doSearch();
+    })
+    document.querySelector('.search-loading').classList.add('hidden');
+    document.querySelector('.search-input').classList.remove('hidden');
+    document.querySelector('.search-text').focus();
+  }
+
+  function buildIndex () {
+    document.querySelector('.search-loading').classList.remove('hidden');
+    fetch('/searchindex.json')
+      .then(function (response) {
+        return response.json();
+      })
+      .then(function (data) {
+        flexSearch.add(data);
+      });
+  }
+
+  buildIndex();
+  enableUI();
+})();