javascript - 如何使输入匹配按 Enter 键(如 ctrl+f)的计数器？

Question

我创建了像 ctrl+f 这样的搜索和突出显示功能，并且我正在尝试找出如何与 html 标签数组进行交互。例如，我有这一行，它将滚动到与用户输入的任何内容相匹配的单词的第一次出现并突出显示它(关键字被包裹在 <mark> 标记中):

//scroll to searched keyword
var element = document.getElementsByTagName("mark")[0];
if(element){
    window.scroll({top: element.offsetTop, behavior: 'smooth'});
}

单击 Enter 后如何使其滚动到下一个下一个元素？我不知道如何使这个 [0] 增加。 这是完整的代码，以防万一:https://codepen.io/MarounLobo/project/editor/DVQwan

Answer 1

您可以使用变量来存储搜索结果中的当前索引。

if (e.key === 'Enter') {
    var elements = document.getElementsByTagName("mark");
    window.scroll({top: elements[++count].offsetTop, behavior: 'smooth'})
} else {
  count = 0;
  var element = document.getElementsByTagName("mark")[0];
    if(element){
        window.scroll({top: element.offsetTop, behavior: 'smooth'});
    }
}

<!-- Search field -->
<input type="text" id="keywords" placeholder="Search on the page..."></input>
<div id="txt"><div class="faq-question"><h4>What is Lorem Ipsum?</h4>
<p>Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.</p></div>

<div class="faq-question"><h4>Why do we use it?</h4>
<p>It is a long established fact that a reader will be distracted by the readable content of a page when looking at its layout. The point of using Lorem Ipsum is that it has a more-or-less normal distribution of letters, as opposed to using 'Content here, content here', making it look like readable English. Many desktop publishing packages and web page editors now use Lorem Ipsum as their default model text, and a search for 'lorem ipsum' will uncover many web sites still in their infancy. Various versions have evolved over the years, sometimes by accident, sometimes on purpose (injected humour and the like).</p></div>


<div class="faq-question"><h4>Where does it come from?</h4>
<p>Contrary to popular belief, Lorem Ipsum is not simply random text. It has roots in a piece of classical Latin literature from 45 BC, making it over 2000 years old. Richard McClintock, a Latin professor at Hampden-Sydney College in Virginia, looked up one of the more obscure Latin words, consectetur, from a Lorem Ipsum passage, and going through the cites of the word in classical literature, discovered the undoubtable source. Lorem Ipsum comes from sections 1.10.32 and 1.10.33 of "de Finibus Bonorum et Malorum" (The Extremes of Good and Evil) by Cicero, written in 45 BC. This book is a treatise on the theory of ethics, very popular during the Renaissance. The first line of Lorem Ipsum, "Lorem ipsum dolor sit amet..", comes from a line in section 1.10.32.</p></div></div>

<style>
.sticky-faqsearch {position: sticky; top: 30px; box-shadow: 0px 5px 10px #4f4f5d29;}
</style>

<script>
// Original JavaScript code by Chirp Internet: chirpinternet.eu
// Please acknowledge use of this code by including this header.

function Hilitor(id, tag)
{

  // private variables
  var targetNode = document.getElementById("txt")
  var hiliteTag = tag || "MARK";
  var skipTags = new RegExp("^(?:" + hiliteTag + "|SCRIPT|FORM|SPAN)$");
  // var colors = ["#ff6", "#a0ffff", "#9f9", "#f99", "#f6f"];
  var colors = ["#aac42a", "#80bd01", "#33a643"];
  var wordColor = [];
  var colorIdx = 0;
  var matchRegExp = "";
  var openLeft = false;
  var openRight = false;

  // characters to strip from start and end of the input string
  var endRegExp = new RegExp('^[^\\w]+|[^\\w]+$', "g");

  // characters used to break up the input string into words
  var breakRegExp = new RegExp('[^\\w\'-]+', "g");

  this.setEndRegExp = function(regex) {
    endRegExp = regex;
    return endRegExp;
  };

  this.setBreakRegExp = function(regex) {
    breakRegExp = regex;
    return breakRegExp;
  };

  this.setMatchType = function(type)
  {
    switch(type)
    {
      case "left":
        this.openLeft = false;
        this.openRight = true;
        break;

      case "right":
        this.openLeft = true;
        this.openRight = false;
        break;

      case "open":
        this.openLeft = this.openRight = true;
        break;

      default:
        this.openLeft = this.openRight = false;

    }
  };

  this.setRegex = function(input)
  {
    input = input.replace(endRegExp, "");
    input = input.replace(breakRegExp, "|");
    input = input.replace(/^\||\|$/g, "");
    if(input) {
      var re = "(" + input + ")";
      if(!this.openLeft) {
        re = "\\b" + re;
      }
      if(!this.openRight) {
        re = re + "\\b";
      }
      matchRegExp = new RegExp(re, "i");
      return matchRegExp;
    }
    return false;
  };

  this.getRegex = function()
  {
    var retval = matchRegExp.toString();
    retval = retval.replace(/(^\/(\\b)?|\(|\)|(\\b)?\/i$)/g, "");
    retval = retval.replace(/\|/g, " ");
    return retval;
  };

  // recursively apply word highlighting
  this.hiliteWords = function(node)
  {
    if(node === undefined || !node) return;
    if(!matchRegExp) return;
    if(skipTags.test(node.nodeName)) return;

    if(node.hasChildNodes()) {
      for(var i=0; i < node.childNodes.length; i++)
        this.hiliteWords(node.childNodes[i]);
    }
    if(node.nodeType == 3) { // NODE_TEXT
      if((nv = node.nodeValue) && (regs = matchRegExp.exec(nv))) {
        if(!wordColor[regs[0].toLowerCase()]) {
          wordColor[regs[0].toLowerCase()] = colors[colorIdx++ % colors.length];
        }

        var match = document.createElement(hiliteTag);
        match.appendChild(document.createTextNode(regs[0]));
        match.style.backgroundColor = wordColor[regs[0].toLowerCase()];
        match.style.color = "#000";

        var after = node.splitText(regs.index);
        after.nodeValue = after.nodeValue.substring(regs[0].length);
        node.parentNode.insertBefore(match, after);
      }
    };
  };

  // remove highlighting
  this.remove = function()
  {
    var arr = document.getElementsByTagName(hiliteTag);
    while(arr.length && (el = arr[0])) {
      var parent = el.parentNode;
      parent.replaceChild(el.firstChild, el);
      parent.normalize();
    }
  };

  // start highlighting at target node
  this.apply = function(input)
  {
    this.remove();
    if(input === undefined || !(input = input.replace(/(^\s+|\s+$)/g, ""))) {
      return;
    }
    if(this.setRegex(input)) {
      this.hiliteWords(targetNode);
    }
    return matchRegExp;
  };

}
</script>
<script type="text/javascript">

//highlight searched keyword
window.addEventListener("DOMContentLoaded", function(e) {
var myHilitor2 = new Hilitor("playground");
myHilitor2.setMatchType("left");
let count = 0;
document.getElementById("keywords").addEventListener("keyup", function(e) {
    myHilitor2.apply(this.value);

  
    //Hide unrelated search results (hides faq-question with no matches to input)
    var questions = document.getElementsByClassName("faq-question");

    for(x = 0; x < questions.length; x++) {
        if(questions[x].getElementsByTagName('mark').length){
            questions[x].style.display = "block";
            // console.log("input exists");
        } else {
            questions[x].style.display = "none";
            // console.log("no matched keywords in this section");
        }
        //if page doesnt contain mark set display to block
        if (document.getElementsByTagName('mark').length == 0) {
            questions[x].style.display = "block";
            // console.log("no input");
        }
    }

    //scroll to searched keyword
    

////////////////////////////////////////////////////////////////////////
    // counter like 0/100 in ctrl+f
if (e.key === 'Enter') {
    var elements = document.getElementsByTagName("mark");
    window.scroll({top: elements[++count].offsetTop, behavior: 'smooth'})
} else {
    count = 0;
  var element = document.getElementsByTagName("mark")[0];
    if(element){
        window.scroll({top: element.offsetTop, behavior: 'smooth'});
    }
}
/////////////////////////////////////////////////////////////////////////    



}, false);
}, false);




//search bar sticks to the top on scroll
window.onscroll = function() {seatchStickToTop()};

var faqsearch = document.getElementById("keywords");
var sticky = faqsearch.offsetTop;

function seatchStickToTop() {
if (window.pageYOffset > sticky) {
    faqsearch.classList.add("sticky-faqsearch");
} else {
    faqsearch.classList.remove("sticky-faqsearch");
}
}

</script>