I am trying to make a search like ctrl+f. I have a function that scrolls to the next keyword when you hit enter. I'm trying to make it to reset the count once you went through all the words, but it just gives me an error. For example if I search "Lorem" it will return 13 matches, so after I hit enter for the 13th time it supposed to reset, but it gives me an error instead. I dont get why (count < elements.length) doesnt work. This is the part where I'm stuck:
P.S. To avoid the confusion, "mark" is a custom element tag that gets wrapped to the words in the text that matches the input and then highlights it.
//scroll to searched keyword
if (e.key === 'Enter') {
var elements = document.getElementsByTagName("mark");
if (count < elements.length) {
window.scroll({top: elements[++count].offsetTop, behavior: 'smooth'})
} else {
count = 0;
window.scroll({top: elements[0].offsetTop, behavior: 'smooth'});
}
console.log("length " + elements.length);
} else {
count = 0;
var element = document.getElementsByTagName("mark")[0];
if(element){
window.scroll({top: element.offsetTop, behavior: 'smooth'});
}
}
console.log(count);
// 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;
};
}<!-- 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 type="text/javascript">
//highlight searched keyword
window.addEventListener("DOMContentLoaded", function(e) {
var myHilitor2 = new Hilitor("playground");
myHilitor2.setMatchType("left");
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
var element = document.getElementsByTagName("mark")[0];
if(element){
window.scroll({top: element.offsetTop, behavior: 'smooth'});
}
////////////////////////////////////////////////////////////////////////
//scroll to searched keyword
if (e.key === 'Enter') {
var elements = document.getElementsByTagName("mark");
if (count < elements.length) {
window.scroll({top: elements[++count].offsetTop, behavior: 'smooth'})
} else {
count = 0;
window.scroll({top: elements[0].offsetTop, behavior: 'smooth'});
}
console.log("length " + elements.length);
} else {
count = 0;
var element = document.getElementsByTagName("mark")[0];
if(element){
window.scroll({top: element.offsetTop, behavior: 'smooth'});
}
}
console.log(count);
/////////////////////////////////////////////////////////////////////////
}, 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>Let's review this part of your code:
if (count < elements.length) {
window.scroll({top: elements[++count].offsetTop, behavior: 'smooth'})
} else {
count = 0;
window.scroll({top: elements[0].offsetTop, behavior: 'smooth'});
}
When count < elements.length, you go through the first branch. In there, you use ++count, meaning that if count was originally elements.length - 1, you're now trying to access elements[elements.length] which is out of bounds and therefore undefined.
Simply checking if (count + 1 < elements.length) should work, i.e. "is the next element still in the list?" basically.