hexo-theme-stellar/source/js/search/local-search.js

// A local search script with the help of
// [hexo-generator-search](https://github.com/PaicHyperionDev/hexo-generator-search)
// Copyright (C) 2015
// Joseph Pan <http://github.com/wzpan>
// Shuhao Mao <http://github.com/maoshuhao>
// This library is free software; you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as
// published by the Free Software Foundation; either version 2.1 of the
// License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
// 02110-1301 USA
//
// Modified by:
// Pieter Robberechts <http://github.com/probberechts>

/*exported searchFunc*/
var searchFunc = function(path, filter, wrapperId, searchId, contentId) {

  function getAllCombinations(keywords) {
    var i, j, result = [];

    for (i = 0; i < keywords.length; i++) {
        for (j = i + 1; j < keywords.length + 1; j++) {
            result.push(keywords.slice(i, j).join(" "));
        }
    }
    return result;
  }

  $.ajax({
    url: path,
    dataType: "json",
    success: function(jsonResponse) {
      var datas = jsonResponse;
      var $input = document.getElementById(searchId);
      if (!$input) { return; }
      var $resultContent = document.getElementById(contentId);
      var $wrapper = document.getElementById(wrapperId);

      $input.addEventListener("input", function(){
        var resultList = [];
        var keywords = getAllCombinations(this.value.trim().toLowerCase().split(" "))
          .sort(function(a,b) { return b.split(" ").length - a.split(" ").length; });
        $resultContent.innerHTML = "";
        if (this.value.trim().length <= 0) {
          $wrapper.setAttribute('searching', 'false');
          return;
        }
        $wrapper.setAttribute('searching', 'true');
        // perform local searching
        datas.forEach(function(data) {
          if (!data.content?.trim().length) { return }
          var matches = 0;
          if (filter && !data.path.includes(filter)) { return }
          var dataTitle = data.title?.trim() || 'Untitled';
          var dataTitleLowerCase = dataTitle.toLowerCase();
          var dataContent = data.content;
          var dataContentLowerCase = dataContent.toLowerCase();
          var dataUrl = data.path;
          var indexTitle = -1;
          var indexContent = -1;
          var firstOccur = -1;
          // only match artiles with not empty contents
          if (dataContent !== "") {
            keywords.forEach(function(keyword) {
              indexTitle = dataTitleLowerCase.indexOf(keyword);
              indexContent = dataContentLowerCase.indexOf(keyword);

              if( indexTitle >= 0 || indexContent >= 0 ){
                matches += 1;
                if (indexContent < 0) {
                  indexContent = 0;
                }
                if (firstOccur < 0) {
                  firstOccur = indexContent;
                }
              }
            });
          }
          // show search results
          if (matches > 0) {
            var searchResult = {};
            searchResult.rank = matches;
            searchResult.str = "<li><a href='"+ dataUrl +"'><span class='search-result-title'>"+ dataTitle +"</span>";
            if (firstOccur >= 0) {
              // cut out 100 characters
              var start = firstOccur - 20;
              var end = firstOccur + 80;

              if(start < 0){
                start = 0;
              }

              if(start == 0){
                end = 100;
              }

              if(end > dataContent.length){
                end = dataContent.length;
              }

              var matchContent = dataContent.substring(start, end);

              // highlight all keywords
              var regS = new RegExp(keywords.join("|"), "gi");
              matchContent = matchContent.replace(regS, function(keyword) {
                return "<span class=\"search-keyword\">"+keyword+"</span>";
              });

              searchResult.str += "<p class=\"search-result-content\">" + matchContent +"...</p>";
            }
            searchResult.str += "</a></li>";
            resultList.push(searchResult);
          }
        });
        if (resultList.length) {
          resultList.sort(function(a, b) {
              return b.rank - a.rank;
          });
          var result ="<ul class=\"search-result-list\">";
          for (var i = 0; i < resultList.length; i++) {
            result += resultList[i].str;
          }
          result += "</ul>";
          $resultContent.innerHTML = result;
        }
      });
    }
  });
};

utils.jq(() => {
  var $inputArea = $("input#search-input");
    if ($inputArea.length == 0) {
      return;
    }
    var $resultArea = document.querySelector("div#search-result");
    $inputArea.focus(function() {
      var path = ctx.search.path;
      if (path.startsWith('/')) {
        path = path.substring(1);
      }
      path = ctx.root + path;
      const filter = $inputArea.attr('data-filter') || '';
      searchFunc(path, filter, 'search-wrapper', 'search-input', 'search-result');
    });
    $inputArea.keydown(function(e) {
      if (e.which == 13) {
        e.preventDefault();
      }
    });
    var observer = new MutationObserver(function(mutationsList, observer) {
      if (mutationsList.length == 1) {
        if (mutationsList[0].addedNodes.length) {
          $('.search-wrapper').removeClass('noresult');
        } else if (mutationsList[0].removedNodes.length) {
          $('.search-wrapper').addClass('noresult');
        }
      }
    });
    observer.observe($resultArea, { childList: true });
  });