Develop Reference

Error or bug when switching CSS classes by JavaScript when dragging with mouse [closed]

Closed. This question needs debugging details. It is not currently accepting answers.
Edit the question to include desired behavior, a specific problem or error, and the shortest code necessary to reproduce the problem. This will help others answer the question.
Closed 1 year ago.
Improve this question
Ok, here a simple code, which changes td class when you click on them:
const btn = document.getElementsByTagName("input")[0];
btn.addEventListener("click", function(event){
let cells = document.getElementsByTagName("td");
for (let i=0; i<cells.length; i++) {
cells[i].classList = ""
};
CounterCells();
})
const tabl = document.getElementsByTagName("table")[0];
tabl.addEventListener("click", function(event){
if (event.target.classList == ""){
event.target.classList.add("green");
console.log("Nothing to green");
} else if (event.target.classList.contains("white")){
event.target.classList.replace("white", "green");
console.log("White to green");
} else if (event.target.classList.contains("green")){
event.target.classList.replace("green", "red");
console.log("Green to red");
} else if (event.target.classList.contains("red")) {
event.target.classList.replace("red", "white");
console.log("Red to white");
}
CounterCells();
})
function CounterCells() {
let cells = document.getElementsByTagName("td");
let countWhites = 0;
let countGreens = 0;
let countReds = 0;
for (let i=0; i<cells.length; i++) {
if (cells[i].classList == "") {
countWhites++
}
if (cells[i].classList.contains("white")) {
countWhites++
}
if (cells[i].classList.contains("green")) {
countGreens++
}
if (cells[i].classList.contains("red")) {
countReds++
}
}
const p = document.getElementById("demo");
p.innerHTML = "Whites: "+countWhites+"<br> Greens: "+countGreens+"<br> Reds: "+countReds;
}
table {
border-collapse: collapse;
}
td {
border: 1px solid grey;
width: 2rem;
height: 2rem;
text-align: center;
cursor: pointer;
user-select: none;
}
.green {
background-color: green;
}
.red {
background-color: red;
}
.white {
background-color: white;
}
<input type="button" value="Reset">
<br>
<br>
<table>
<tr>
<td>1</td>
<td>2</td>
<td>3</td>
</tr>
<tr>
<td>4</td>
<td>5</td>
<td>6</td>
</tr>
<tr>
<td>7</td>
<td>8</td>
<td>9</td>
</tr>
</table>
<p id="demo"></p>
If you click it -- anything works fine, but now try to click on cell number one and drag mouse over cell number three and then release mouse button -- class will be assigned to tr not to last td number 3.
Why is that?
https://jsfiddle.net/foxnadir/Ls6p7j1z/3/

The problem in your code was that you were attaching the click event to the table element, when only one td can be clicked at a time.
I also changed the event from click to mousedown so that when the user drags from 1 to 3, 1 changes color, but if this behavior is not what you wanted, you can change it back.
Here is the working code:
const btn = document.getElementsByTagName("input")[0];
btn.addEventListener("click", function(event) {
let cells = document.getElementsByTagName("td");
for (let i = 0; i < cells.length; i++) {
cells[i].classList = ""
};
CounterCells();
})
let cells = document.getElementsByTagName("td");
for (i = 0; i < cells.length; i++) {
cells[i].addEventListener("mousedown", function(event) {
if (event.target.classList == "") {
event.target.classList.add("green");
console.log("Nothing to green");
} else if (event.target.classList.contains("white")) {
event.target.classList.replace("white", "green");
console.log("White to green");
} else if (event.target.classList.contains("green")) {
event.target.classList.replace("green", "red");
console.log("Green to red");
} else if (event.target.classList.contains("red")) {
event.target.classList.replace("red", "white");
console.log("Red to white");
}
CounterCells();
})
}
function CounterCells() {
let countWhites = 0;
let countGreens = 0;
let countReds = 0;
for (let i = 0; i < cells.length; i++) {
if (cells[i].classList == "") {
countWhites++
}
if (cells[i].classList.contains("white")) {
countWhites++
}
if (cells[i].classList.contains("green")) {
countGreens++
}
if (cells[i].classList.contains("red")) {
countReds++
}
}
const p = document.getElementById("demo");
p.innerHTML = "Whites: " + countWhites + "<br> Greens: " + countGreens + "<br> Reds: " + countReds;
}
table {
border-collapse: collapse;
}
td {
border: 1px solid grey;
width: 2rem;
height: 2rem;
text-align: center;
cursor: pointer;
user-select: none;
}
tr {
-webkit-touch-callout: none;
-webkit-user-select: none;
-khtml-user-select: none;
-moz-user-select: none;
-ms-user-select: none;
user-select: none;
}
td {
-webkit-touch-callout: none;
-webkit-user-select: none;
-khtml-user-select: none;
-moz-user-select: none;
-ms-user-select: none;
user-select: none;
}
.green {
background-color: green;
}
.red {
background-color: red;
}
.white {
background-color: white;
}
<input type="button" value="Reset">
<br>
<br>
<table>
<tr>
<td>1</td>
<td>2</td>
<td>3</td>
</tr>
<tr>
<td>4</td>
<td>5</td>
<td>6</td>
</tr>
<tr>
<td>7</td>
<td>8</td>
<td>9</td>
</tr>
</table>
<p id="demo"></p>

How to add a number dynamically with Javascript to the first cell

I'm learning Javascript and i'm stuck at the moment. When the user input their first name, last name, age and clicks on the button "add", 1 new row and 4 new cells are being added to the table with the value of the users input.
My question is: how do I get the first cell to be a number? Which in this case should be number 4. If the user adds another row with value it should become number 5. etc.
If somebody could point me in a direction or show me another way to do it, that would help. Thanks! (css added just for visuals)
function allID(id) {
return document.getElementById(id);
}
function allEvents() {
allID("voegdatatoe").onclick = function () {
voegToeGegevens();
};
}
allEvents();
function voegToeGegevens() {
var formulier = allID("invoerformulier");
var nieuweGegevens = [];
for (var i = 0; i < formulier.length; i++) {
nieuweGegevens[i] = formulier.elements[i].value;
}
var uitvoertabel = allID("uitvoertabel");
var nieuweRij = uitvoertabel.insertRow(-1);
for (i = 0; i < 4; i++) {
var NieuweCell = nieuweRij.insertCell(i);
NieuweCell.innerHTML = nieuweGegevens[i];
}
}
var row = document.getElementsByClassName("rownmr");
var i = 0;
for (i = 0; i < row.length; i++) {
row[i].innerHTML = i + 1;
}
table,
th,
td {
border-collapse: collapse;
border: 1px solid black;
}
th,
td {
padding: 5px;
}
th {
text-align: left;
background-color: #c95050;
color: white;
}
.uitvoertabel {
width: 60%;
}
.uitvoertabel tr:nth-child(even) {
background-color: #eee;
}
.uitvoertabel tbody tr td:first-child {
width: 30px;
}
.invoerform {
margin-top: 50px;
width: 30%;
}
.invoerform input,
label {
display: block;
}
.invoerform label {
margin-bottom: 5px;
margin-top: 10px;
}
#voegdatatoe {
margin-top: 30px;
}
input:focus {
border: 1px solid #d45757;
outline: none;
}
<table class="uitvoertabel" id="uitvoertabel">
<thead>
<tr>
<th></th>
<th>Voornaam</th>
<th>Achternaam</th>
<th>Leeftijd</th>
</tr>
</thead>
<tbody>
<tr>
<td class="rownmr"></td>
<td>Johan</td>
<td>cruijff</td>
<td>54</td>
</tr>
<tr>
<td class="rownmr"></td>
<td>Frans</td>
<td>Bauer</td>
<td>47</td>
</tr>
<tr>
<td class="rownmr"></td>
<td>Willem</td>
<td>van Oranje</td>
<td>80</td>
</tr>
</tbody>
</table>
<form action="" id="invoerformulier" class="invoerform">
<label>Voornaam:</label>
<input type="text" name="vnaam" id="voornaam">
<label>Achternaam:</label>
<input type="text" name="anaam" id="achternaam">
<label>Leeftijd:</label>
<input type="text" name="points" id="leeftijd">
</form>
<button id="voegdatatoe">Voeg toe</button>

There are a number of ways you could store this information, from a global variable (not recommended) to some local closure, or even localStorage. But you have the information in the DOM, so it might be simplest to use it.
One way to do this would be to scan the ids, find their maximum, and add one to it. This involves a few changes to your code. First, we would add some code to scan your id cells for the largest value:
var rows = document.getElementsByClassName("rownmr");
var highestId = Math.max(...([...rows].map(row => Number(row.textContent))))
Then we would start your content array with a new value one higher than that maximum:
var nieuweGegevens = [highestId + 1];
And your loop needs to take this into account by adding one to the index
for (var i = 0; i < formulier.length; i++) {
nieuweGegevens[i + 1] = formulier.elements[i].value;
}
Finally, we need to add the right class to that new cell so that on the next call, it will continue to work:
for (i = 0; i < 4; i++) {
var NieuweCell = nieuweRij.insertCell(i);
NieuweCell.innerHTML = nieuweGegevens[i];
if (i === 0) { /**** new ****/
NieuweCell.classList.add("rownmr") /**** new ****/
} /**** new ****/
}
You can see these changes inline in this snippet:
function allID(id) {
return document.getElementById(id);
}
function allEvents() {
allID("voegdatatoe").onclick = function () {
voegToeGegevens();
};
}
allEvents();
function voegToeGegevens() {
var formulier = allID("invoerformulier");
var rows = document.getElementsByClassName("rownmr");
var highestId = Math.max(...([...rows].map(row => Number(row.textContent))))
var nieuweGegevens = [highestId + 1];
for (var i = 0; i < formulier.length; i++) {
nieuweGegevens[i + 1] = formulier.elements[i].value;
}
var uitvoertabel = allID("uitvoertabel");
var nieuweRij = uitvoertabel.insertRow(-1);
for (i = 0; i < 4; i++) {
var NieuweCell = nieuweRij.insertCell(i);
NieuweCell.innerHTML = nieuweGegevens[i];
if (i === 0) {
NieuweCell.classList.add("rownmr")
}
}
}
var row = document.getElementsByClassName("rownmr");
var i = 0;
for (i = 0; i < row.length; i++) {
row[i].innerHTML = i + 1;
}
table,
th,
td {
border-collapse: collapse;
border: 1px solid black;
}
th,
td {
padding: 5px;
}
th {
text-align: left;
background-color: #c95050;
color: white;
}
.uitvoertabel {
width: 60%;
}
.uitvoertabel tr:nth-child(even) {
background-color: #eee;
}
.uitvoertabel tbody tr td:first-child {
width: 30px;
}
.invoerform {
margin-top: 50px;
width: 30%;
}
.invoerform input,
label {
display: block;
}
.invoerform label {
margin-bottom: 5px;
margin-top: 10px;
}
#voegdatatoe {
margin-top: 30px;
}
input:focus {
border: 1px solid #d45757;
outline: none;
}
<table class="uitvoertabel" id="uitvoertabel">
<thead>
<tr>
<th></th>
<th>Voornaam</th>
<th>Achternaam</th>
<th>Leeftijd</th>
</tr>
</thead>
<tbody>
<tr>
<td class="rownmr"></td>
<td>Johan</td>
<td>cruijff</td>
<td>54</td>
</tr>
<tr>
<td class="rownmr"></td>
<td>Frans</td>
<td>Bauer</td>
<td>47</td>
</tr>
<tr>
<td class="rownmr"></td>
<td>Willem</td>
<td>van Oranje</td>
<td>80</td>
</tr>
</tbody>
</table>
<form action="" id="invoerformulier" class="invoerform">
<label>Voornaam:</label>
<input type="text" name="vnaam" id="voornaam">
<label>Achternaam:</label>
<input type="text" name="anaam" id="achternaam">
<label>Leeftijd:</label>
<input type="text" name="points" id="leeftijd">
</form>
<button id="voegdatatoe">Voeg toe</button>
Note that this will continue to work on subsequent adds.

Add additional the length+1 param in the arrays of data
function allID(id) {
return document.getElementById(id);
}
function allEvents() {
allID("voegdatatoe").onclick = function () {
voegToeGegevens();
};
}
allEvents();
function voegToeGegevens() {
var row = document.getElementsByTagName("tr");
var formulier = allID("invoerformulier");
var nieuweGegevens = [];
nieuweGegevens.push(row.length) //length param for first column
for (var i = 0; i < formulier.length; i++) {
nieuweGegevens[i+1] = formulier.elements[i].value; //saving values from i=1
}
var uitvoertabel = allID("uitvoertabel");
var nieuweRij = uitvoertabel.insertRow(-1);
for (i = 0; i < 4; i++) {
var NieuweCell = nieuweRij.insertCell(i);
NieuweCell.innerHTML = nieuweGegevens[i];
}
}
var row = document.getElementsByClassName("rownmr");
var i = 0;
for (i = 0; i < row.length; i++) {
row[i].innerHTML = i + 1;
}
table,
th,
td {
border-collapse: collapse;
border: 1px solid black;
}
th,
td {
padding: 5px;
}
th {
text-align: left;
background-color: #c95050;
color: white;
}
.uitvoertabel {
width: 60%;
}
.uitvoertabel tr:nth-child(even) {
background-color: #eee;
}
.uitvoertabel tbody tr td:first-child {
width: 30px;
}
.invoerform {
margin-top: 50px;
width: 30%;
}
.invoerform input,
label {
display: block;
}
.invoerform label {
margin-bottom: 5px;
margin-top: 10px;
}
#voegdatatoe {
margin-top: 30px;
}
input:focus {
border: 1px solid #d45757;
outline: none;
}
<table class="uitvoertabel" id="uitvoertabel">
<thead>
<tr>
<th></th>
<th>Voornaam</th>
<th>Achternaam</th>
<th>Leeftijd</th>
</tr>
</thead>
<tbody>
<tr>
<td class="rownmr"></td>
<td>Johan</td>
<td>cruijff</td>
<td>54</td>
</tr>
<tr>
<td class="rownmr"></td>
<td>Frans</td>
<td>Bauer</td>
<td>47</td>
</tr>
<tr>
<td class="rownmr"></td>
<td>Willem</td>
<td>van Oranje</td>
<td>80</td>
</tr>
</tbody>
</table>
<form action="" id="invoerformulier" class="invoerform">
<label>Voornaam:</label>
<input type="text" name="vnaam" id="voornaam">
<label>Achternaam:</label>
<input type="text" name="anaam" id="achternaam">
<label>Leeftijd:</label>
<input type="text" name="points" id="leeftijd">
</form>
<button id="voegdatatoe">Voeg toe</button>

As I note that none of the answers made, does not seem to have the approval of Niekket (no validation for anybody),
and that the question asked is accompanied by a very rough example (the author admits to being bloked in his apprenticeship), using a lot of useless code...
So I propose this complete solution, which I hope is enlightening enough on the proper way of coding its problem ( imho ).
const
TableBody_uitvoertabel = document.querySelector('#uitvoertabel > tbody'),
form_invoerformulier = document.querySelector('#invoerformulier'),
in_voornaam = document.querySelector('#voornaam'),
in_achternaam = document.querySelector('#achternaam'),
in_leeftijd = document.querySelector('#leeftijd')
;
var
RowCount = 0; // global..
// place numbers in the first column
document.querySelectorAll('#uitvoertabel > tbody > tr td:first-child').forEach(
elmTR=>{ elmTR.textContent = ++RowCount }
);
form_invoerformulier.onsubmit = function(e) {
e.preventDefault();
let
column = 0,
row = TableBody_uitvoertabel.insertRow(-1)
;
row.insertCell(column++).textContent = ++RowCount;
row.insertCell(column++).textContent = in_voornaam.value;
row.insertCell(column++).textContent = in_achternaam.value;
row.insertCell(column++).textContent = in_leeftijd.value;
this.reset();
}
table, th, td {
border-collapse: collapse;
border: 1px solid black;
}
th, td { padding: 5px; }
th {
text-align: left;
background-color: #c95050;
color: white;
}
table.uitvoertabel { width: 60%; }
table.uitvoertabel tr:nth-child(even) {
background-color: #eee;
}
table.uitvoertabel tbody tr td:first-child {
width: 30px;
}
form.invoerform {
margin-top: 50px;
width: 30%;
}
form.invoerform input,
form.invoerform label {
display: block;
}
form.invoerform label {
margin-bottom: 5px;
margin-top: 10px;
}
form.invoerform button {
margin-top: 30px;
}
form.invoerform input:focus {
border-color: #d45757;
outline: none;
}
<table class="uitvoertabel" id="uitvoertabel">
<thead>
<tr>
<th></th><th>Voornaam</th><th>Achternaam</th><th>Leeftijd</th>
</tr>
</thead>
<tbody>
<tr>
<td></td><td>Johan</td><td>cruijff</td><td>54</td>
</tr>
<tr>
<td></td><td>Frans</td><td>Bauer</td><td>47</td>
</tr>
<tr>
<td></td><td>Willem</td><td>van Oranje</td><td>80</td>
</tr>
</tbody>
</table>
<form id="invoerformulier" class="invoerform">
<label>Voornaam:</label>
<input type="text" name="vnaam" id="voornaam">
<label>Achternaam:</label>
<input type="text" name="anaam" id="achternaam">
<label>Leeftijd:</label>
<input type="text" name="points" id="leeftijd">
<button type="submit">Voeg toe</button>
<button type="reset">Reset</button>
</form>

I think that the main issue is that you only manually set the rownmrs for the first time from line var row = document.getElementsByClassName("rownmr");
rather than every time you click on the "Voeg toe" button.
Ideally, for your hard coded numbers, they would be in the markup and the logic to grab the next rownmr to display and the adding of that cell happens on click.
html
<table class="uitvoertabel" id="uitvoertabel">
<thead>
<tr>
<th></th>
<th>Voornaam</th>
<th>Achternaam</th>
<th>Leeftijd</th>
</tr>
</thead>
<tbody>
<tr>
<td class="rownmr">1</td>
<td>Johan</td>
<td>cruijff</td>
<td>54</td>
</tr>
<tr>
<td class="rownmr">2</td>
<td>Frans</td>
<td>Bauer</td>
<td>47</td>
</tr>
<tr>
<td class="rownmr">3</td>
<td>Willem</td>
<td>van Oranje</td>
<td>80</td>
</tr>
</tbody>
</table>
<form action="" id="invoerformulier" class="invoerform">
<label>Voornaam:</label>
<input type="text" name="vnaam" id="voornaam">
<label>Achternaam:</label>
<input type="text" name="anaam" id="achternaam">
<label>Leeftijd:</label>
<input type="text" name="points" id="leeftijd">
</form>
<button id="voegdatatoe">Voeg toe</button>
js
function allID(id) {
return document.getElementById(id);
}
function allEvents() {
allID("voegdatatoe").onclick = function () {
voegToeGegevens();
};
}
allEvents();
function voegToeGegevens() {
var formulier = allID("invoerformulier");
var nieuweGegevens = [];
for (var i = 0; i < formulier.length; i++) {
nieuweGegevens[i] = formulier.elements[i].value;
}
var allRownmrs = document.getElementsByClassName('rownmr');
var lastRownmr = allRownmrs[allRownmrs.length - 1].innerHTML;
var nextRownmr = parseInt(lastRownmr) + 1;
var uitvoertabel = allID("uitvoertabel");
var nieuweRij = uitvoertabel.insertRow(-1);
for (i = 0; i < 4; i++) {
var NieuweCell = nieuweRij.insertCell(i)
// you probably can refactor here
if (i === 0) {
NieuweCell.innerHTML = nextRownmr
} else {
NieuweCell.innerHTML = nieuweGegevens[i - 1];
}
}
}

Jquery filter table if fits into input range

Question:
I have a HTML with type number i want to ge the value using jQuery create a range by adding 10% on either side then checking if each row falls in the range if not hide the row.
Code:
HTML
<input type="number" id="myPrice" onkeyup="myPriceFunction()" placeholder="Enter amount.." title="Type in a amount" min="0">
JavaScript/jQuery
$(document).ready(function(){
$("#myPrice").on("keyup", function() {
priceLow = $(this).val() * 0.9;
priceHigh = $(this).val() * 1.1;
});
});
JS fiddle
https://jsfiddle.net/nx30zqjd/7/
Other:
I am using:
.addClass('discarded').hide();
.removeClass('discarded').show();
to hide and show rows
Expected Results:
I want the range to be created with priceLow and priceHigh then get price column get rid of $ and check if it falls within range if not hide using code above.
Update:
I added
$(this).closest('tr').removeClass('discarded').show();
} else {
$(this).closest('tr').addClass('discarded').hide();
}
however then this shows nothing because i don't check discarded rows, if i remove the check for discarded rows it doesn't apply my search to the range not sure if there is a easy way to have both but it seems to be ok for the moment
If you need any more information please ask.
Thanks

You can use this, you just need to iterate and get the values and then check, based on that you can hide and show.
$("#myPrice").on("keyup", function() {
if ($(this).val() === '') {
$("#myTable tr").show();
return;
}
priceLow = $(this).val() * 0.9;
priceHigh = $(this).val() * 1.1;
$("#myTable tr td:nth-child(2)").each(function(e) {
var value = this.textContent.replace('$', '');
if (value >= priceLow && value <= priceHigh) {
$(this).closest('tr').show();
} else {
$(this).closest('tr').hide();
}
})
});
$(document).ready(function() {
});
$(document).ready(function() {
$("#myPrice").on("keyup", function() {
if ($(this).val() === '') {
$("#myTable tr").show();
return;
}
priceLow = $(this).val() * 0.9;
priceHigh = $(this).val() * 1.1;
$("#myTable tr td:nth-child(2)").each(function(e) {
var value = parseFloat(this.textContent.replace('$', ''));
if (value >= priceLow && value <= priceHigh) {
$(this).closest('tr').removeClass('discarded').show();
} else {
$(this).closest('tr').addClass('discarded').hide();
}
})
});
});
<style>* {
box-sizing: border-box;
}
#mySearch {
background-image: url('https://www.w3schools.com/css/searchicon.png');
background-position: 10px 10px;
background-repeat: no-repeat;
width: 100%;
font-size: 16px;
padding: 12px 20px 12px 40px;
border: 1px solid #ddd;
margin-bottom: 12px;
}
#myTable {
border-collapse: collapse;
width: 100%;
border: 1px solid #ddd;
font-size: 18px;
}
#myTable th,
#myTable td {
text-align: left;
padding: 12px;
}
#myTable tr {
border-bottom: 1px solid #ddd;
}
.show {
display: block;
}
a {
color: blue;
text-decoration: none;
/* no underline */
}
</style>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<h2>CPUs</h2>
CPU
Motherboards
<input type="number" id="myPrice" placeholder="Enter amount.." title="Type in a amount" min="0">
<input type="text" id="mySearch" placeholder="Search for cpus.." title="Type in a cpu name">
<table id='myTable'>
<thead>
<tr>
<th>CPU</th>
<th>Price</th>
<th>Mark</th>
<th>Value</th>
<th>Socket</th>
<th>Image</th>
</tr>
</thead>
<tbody>
<tr>
<td><a href='mobo.php?cpu_name=AMD Ryzen 5 2600"' target='_blank'>AMD Ryzen 5 2600</a></td>
<td>$246.05</td>
<td>13537</td>
<td>55.02</td>
<td>AM4</td>
<td><img src=NA height='42' width='42'></td>
</tr>
</tbody>
<tbody>
<tr>
<td><a href='mobo.php?cpu_name=Intel Core i7-8700K"' target='_blank'>Intel Core i7-8700K</a></td>
<td>$585.90</td>
<td>15957</td>
<td>27.24</td>
<td>LGA1151</td>
<td><img src=". $row[" url "]." height='42' width='42'></td>
</tr>
</tbody>
</table>

How to addEventListener to table cells

I'want to add an eventListener to the table cells so each time a table cell is clicked to execute a function .
var getDaysInMonth = function (year, month) {
return new Date(year, month, 0).getDate();
}
var calendar = {
month: function () {
var d = new Date();
return d.getMonth() + this.nextMonth;
},
year: function () {
var y = new Date();
return y.getFullYear();
},
nextMonth: 1,
cellColor: 'white',
}
var loopTable = function () {
var daysInMonth = getDaysInMonth(calendar.year(), calendar.month());
var table = document.getElementById('myTable');
var rows = table.rows;
var l = 1;
var month = calendar.month();
var year = calendar.year();
var firstDay = new Date(year + "-" + month).getDay();
var currentDay = new Date().getDay();
var dayOfMonth = new Date().getDate();
for (let i = 1; i < rows.length; i++) {
if (rows[i] == rows[1]) {
var k = 1;
for (let j = firstDay; j < rows[i].cells.length; j++) {
if (k === dayOfMonth && calendar.nextMonth === 1) {
rows[i].cells[j].style.backgroundColor = calendar.cellColor;
}
if (k <= daysInMonth) {
rows[i].cells[j].innerHTML = k;
k++
}
}
} else {
for (let j = 0; j < rows[i].cells.length; j++) {
if (k === dayOfMonth && calendar.nextMonth === 1) {
rows[i].cells[j].style.backgroundColor = calendar.cellColor;
}
if (k <= daysInMonth) {
rows[i].cells[j].innerHTML = k;
k++
}
}
}
}
}
loopTable();
clickCell();
function monthTitle() {
var monthsArray = ['Jan.', 'Feb.', 'Mar.', 'Apr.', 'May', 'Jun.', 'Jul.', 'Aug.', 'Sept.', 'Oct.', 'Nov.', 'Dec.'];
monthNum = calendar.month();
var monthName = monthsArray[calendar.month() - 1] + '' + calendar.year();
var title = document.getElementById('calendarTitle');
var nextArrow = document.getElementById('nxt');
var leftArrow = document.getElementById('prev');
if (monthName === ('Dec.' + '' + calendar.year())){
xmas();
}
if (monthNum >= 12) {
nextArrow.className += ' inactiveLink';
} else if (monthNum <= 1) {
leftArrow.className += ' inactiveLink';
} else {
nextArrow.classList.remove('inactiveLink');
leftArrow.classList.remove('inactiveLink');
}
title.innerHTML = '';
var titleNode = document.createTextNode(monthName);
title.appendChild(titleNode);
}
monthTitle();
function nextMonth() {
clearTable();
calendar.nextMonth += 1;
monthTitle();
loopTable();
}
function previousMonth() {
clearTable();
calendar.nextMonth -= 1;
monthTitle();
loopTable();
}
function clearTable() {
var table = document.getElementById('myTable');
var rows = table.rows;
for (var i = 1; i < rows.length; i++) {
cells = rows[i].cells;
for (var j = 0; j < cells.length; j++) {
if (cells[j].innerHTML = '') {
cells[j].style.display = 'none';
}
cells[j].innerHTML = '';
cells[j].style.backgroundColor = '#D9534F';
cells[j].style.emptyCells = 'hide';
}
}
}
var next = document.getElementById('nxt');
var previous = document.getElementById('prev');
var table = document.getElementById('myTable');
var cell = table.rows;
next.addEventListener('click', nextMonth);
previous.addEventListener('click', previousMonth);
function clickCell() {
var row = document.getElementById('myTable').rows;
for (var i = 0; i < row.length; i++) {
for (var j = 0; j < row[i].cells.length; j++ ) {
row[i].cells[j].addEventListener('click', function(){
console.log('click');
})
}
}
}
clickCell();
body {
background-color: rgb(0, 121, 191);
}
table {
width: 50%;
background-color: #D9534F;
border: 1px solid white;
padding: 10px;
padding-bottom: 20px;
font-size: 25px;
border-radius: 25px;
position: relative;
margin: auto;
}
td {
border: 1px solid white;
text-align: center;
font-weight: 600;
font-size: 20px;
padding: 20px;
}
th {
height: 50px;
}
.calArrows {
text-decoration: none;
color: white;
font-size: 35px;
}
#nxt {
font-size: 30px;
position: absolute;
top: 0;
right: 25%
}
#prev {
font-size: 30px;
position: absolute;
top: 0;
left: 25%;
}
#calendarTitle {
font-family: 'Indie Flower', cursive;
font-weight: 600;
font-size: 25px;
color: white;
}
.inactiveLink {
cursor: not-allowed;
pointer-events: none;
}
#myTable {
empty-cells: hide;
}
.xmasDec {
width: 90%;
height: 70%;
position: absolute;
top: -10%;
left: 5%;
}
#calWraper {
position: relative;
}
#myCan {
position: absolute;
top: 0;
left: 10%;
width: 90%;
height: 70%;
opacity: 0, 5;
}
<body>
<canvas class="myCan" width="100" height="100"></canvas>
<div id="calWraper">
<table id="myTable">
<caption id="calendarTitle">Test</caption>
<tr>
<th>Sun</th>
<th>Mon</th>
<th>Tue</th>
<th>Wed</th>
<th>Thur</th>
<th>Fri</th>
<th>Sat</th>
</tr>
<tr>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
</tr>
<tr>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
</tr>
<tr>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
</tr>
<tr>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
</tr>
<tr>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
</tr>
<tr>
<td></td>
<td></td>
</tr>
</table>
<canvas id="myCan" width="200" height="200" style="background-color: transparent"></canvas>
<i class="fa fa-arrow-left" ></i>
<i class="fa fa-arrow-right" ></i>
</div>
</html>
I tried by creating a function that it will loop through rows and cells and add the eventListener to each . But it seems that its not working , its working on random instances which is really strange behavior . Here is the function i create:
function clickCell() {
var row = document.getElementById('myTable').rows;
for (var i = 0; i < row.length; i++) {
for (var j = 0; j < row[i].cells.length; j++ ) {
console.log(row[i].cells[j].innerHTML);
row[i].cells[j].addEventListener('click', function(){
console.log('click');
})
}
}
}

It seems your canvas is overlapping your table. Because of that td elements in your table are never clicked.
You will need to add CSS property pointer-events:none to your canvas.
#myCan {
...
pointer-events: none;
}
This way it won't block table from being clicked anymore.
You can also add event listeners to your cells way simpler:
document.querySelectorAll('#myTable td')
.forEach(e => e.addEventListener("click", function() {
// Here, `this` refers to the element the event was hooked on
console.log("clicked")
}));
That creates a separate function for each cell; instead, you could share one function without losing any functionality:
function clickHandler() {
// Here, `this` refers to the element the event was hooked on
console.log("clicked")
}
document.querySelectorAll('#myTable td')
.forEach(e => e.addEventListener("click", clickHandler));
Some browsers still don't have forEach on the HTMLCollection returned by querySelectorAll, but it's easily polyfilled:
if (!HTMLCollection.prototype.forEach) {
Object.defineProperty(HTMLCollection.prototype, "forEach", {
value: Array.prototype.forEach
});
}
If you have to support truly obsolete browsers that don't have Array.prototype.forEach, see the polyfill on MDN.

This is a case for event delegation: Hook the click event on the table (or table body), not individual cells, and then determine which cell was clicked by looking at event.target and its ancestors.
Simplified example:
document.querySelector("#my-table tbody").addEventListener("click", function(event) {
var td = event.target;
while (td !== this && !td.matches("td")) {
td = td.parentNode;
}
if (td === this) {
console.log("No table cell found");
} else {
console.log(td.innerHTML);
}
});
Live Copy:
document.querySelector("#my-table tbody").addEventListener("click", function(event) {
var td = event.target;
while (td !== this && !td.matches("td")) {
td = td.parentNode;
}
if (td === this) {
console.log("No table cell found");
} else {
console.log(td.innerHTML);
}
});
table, td, th {
border: 1px solid #ddd;
}
table {
border-collapse: collapse;
}
td, th {
padding: 4px;
}
<table id="my-table">
<thead>
<tr>
<th>First</th>
<th>Last</th>
</tr>
</thead>
<tbody>
<tr>
<td>Joe</td>
<td>Bloggs</td>
</tr>
<tr>
<td>Muhammad</td>
<td>Abdul</td>
</tr>
<tr>
<td>Maria</td>
<td>Gonzales</td>
</tr>
</tbody>
</table>
Note that instead of the loop you could use the new (experimental) closest method on elements:
var td = event.target.closest("td");
...but A) It's still experimental, and B) It won't stop when it reaches the tbody, so in theory if you had nested tables, would find the wrong cell.
If you need to support browsers that don't have Element.prototype.matches, in this specific case you could use td.tagName !== "TD" instead of !td.matches("td") (note the capitalization).

Using only the DOM objects
Here's an example cell wise event listener added on an HTML table (TicTacToe). It can be achieved easily using 'this' keyword and 'querySelectorAll'
The logic is in the JavaScript file:
First, get all the cells by their 'tag' ("td") using 'querySelectorAll' and save it as a list
Add an event listener to each of the cells, and give a function name to do whatever you want
Inside the event listener function, using this keyword update the cell content, or call other functions or do whatever task you have to complete.
var cells = document.querySelectorAll("td");
for (var cell of cells) {
cell.addEventListener('click', marker)
}
function marker() {
if (this.textContent === 'X') {
this.innerHTML = "O";
} else if (this.textContent === 'O') {
this.innerHTML = " ";
} else {
this.innerHTML = "X";
}
}
td {
text-align: center;
font-size: 50px
}
table,
th,
td {
border: 2px solid black;
width: 300px;
height: 100px;
}
<!DOCTYPE html>
<html lang="en" dir="ltr">
<head>
<meta charset="utf-8">
<title>Tic Tac Toe</title>
</head>
<body>
<table id="ticTac">
<tbody>
<tr>
<td>. </td>
<td>. </td>
<td>. </td>
</tr>
<tr>
<td>. </td>
<td>. </td>
<td>. </td>
</tr>
<tr>
<td>. </td>
<td>. </td>
<td>. </td>
</tr>
</tbody>
</table>
</body>
</html>

How to perform input fields validation and to prevent from adding new row if the fields are empty?

I have a simple table with three input fields (text, date and dropdown) and on click of an "add row" button, new row is getting added. However I need to perform below validation on the input fields; the new row should not get added if the input fields are empty and it should throw an error message. How to achieve that?
Functions to add new row and to delete selected row:
function addRow(tableID) {
var table = document.getElementById(tableID);
var rowCount = table.rows.length;
var row = table.insertRow(rowCount);
var colCount = table.rows[0].cells.length;
for (var i = 0; i < colCount; i++) {
var newcell = row.insertCell(i);
newcell.innerHTML = table.rows[0].cells[i].innerHTML;
//alert(newcell.childNodes);
switch (newcell.childNodes[0].type) {
case "text":
newcell.childNodes[0].value = "";
break;
case "checkbox":
newcell.childNodes[0].checked = false;
break;
case "select-one":
newcell.childNodes[0].selectedIndex = 0;
break;
}
}
}
function deleteRow(tableID) {
try {
var table = document.getElementById(tableID);
var rowCount = table.rows.length;
for (var i = 0; i < rowCount; i++) {
var row = table.rows[i];
var chkbox = row.cells[0].childNodes[0];
if (null != chkbox && true == chkbox.checked) {
if (rowCount <= 1) {
alert("Cannot delete all the rows.");
break;
}
table.deleteRow(i);
rowCount--;
i--;
}
}
} catch (e) {
alert(e);
}
}
body {
font-family: "Open Sans", Helvetica, Arial, sans-serif;
font-weight: 300;
font-size: 12px;
line-height: 30px;
color: #777;
background: #366161;
}
#dataTable {
margin: 0 auto;
margin-top: 30px;
}
.btn {
-webkit-border-radius: 5;
-moz-border-radius: 5;
border-radius: 5px;
font-family: Arial;
color: #ffffff;
font-size: 15px;
background: #2f354a;
padding: 7px 15px 7px 15px;
text-decoration: none;
outline: none;
margin: 30px;
}
.btn:hover {
background: #3cb0fd;
text-decoration: none;
}
.btn_container {
margin: 0 auto;
width: 360px;
}
select option[value="red"] {
background-color: #f00;
}
select option[value="yellow"] {
background-color: #FFFF00;
}
select option[value="green"] {
background-color: #7CFC00;
}
h1.heading {
text-align: center;
color: #ffffff;
}
#errors {
margin-left: 310px;
color: red;
font-size: 16px;
}
<body>
<h1 class="heading"> Simple Form</h1>
<table id="dataTable" width="900px" cellspacing="5" cellpadding="10" style="background:#F0F8FF;border:1px dotted">
<tr>
<td><input type="checkbox" name="chk" /></td>
<td> Name : <input type="text" name="txt" id="fname" placeholder="Enter your name" required/></td>
<td>Date: <input type="date" name="date" id="delivery_date" required/></td>
<td>
Color:
<select name="Color" required>
<option value="red">Red</option>
<option value="yellow">yellow</option>
<option value="green">Green</option>
</select>
</td>
</tr>
</table>
<div class="btn_container">
<input type="button" class="btn" value="Add Row" onclick="addRow('dataTable')" />
<input type="button" class="btn" value="Delete Row" onclick="deleteRow('dataTable')" />
</div>
</body>

This code will check the previous row and, if either the name or date field of that row is empty, a new row won't be added. The alert displays, "Please fill the current row in before adding a new row" but you change the message to anything you like.
var prevName = table.rows[rowCount - 1].cells[1].firstChild.nextSibling.value;
var prevDate = table.rows[rowCount - 1].cells[2].firstChild.nextSibling.value;
if (prevName == "" || prevDate == "") {
alert("Please fill the current row in before adding a new row");
return;
}
Insert it after this line:
var rowCount = table.rows.length;
and before this line:
var row = table.insertRow(rowCount);