I have a table generated from a textarea filled by users, but some of the time, a cell stays empty (and that's all right).
The thing is that the .innerHTML of that cell is also my var y in a script and when that cell is empty (therefore, undefined), my var y becomes UNDEFINED too (the value, not a string), which makes my whole script fail.
Here's a snippet to show the problem:
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
</head>
<body><center>
</center></body>
<!--------- script that generates my table from text areas -->
<script>
function generateTable() {
$('#excel_table1').html("");
var n=1;
var rows=[];
var lng=0;
var maxligne=0;
$('textarea').each(function(){
var data = $(this).val();
if (data !=''){
var rowData = data.split("\n");
rows[n] = rowData;
lng = rowData.length;
if(lng > maxligne)
{
maxligne=lng
}
n++;
}
}
)
var table = $('<table />');
k=0;
while (k < maxligne) {
var row = $('<tr />');
for(var i = 1; i < rows.length; i++)
{
var singleRow = rows[i];
if(singleRow[k]!= undefined){
row.append('<td>'+singleRow[k]+'</td>')
} else {
row.append('<td></td>')
}
}
table.append(row);
k++;
}
$('#excel_table1').append(table);
}
</script>
<textarea placeholder="data 2 Here" name="data1" style="width:100px;height:40px;"></textarea>
<textarea placeholder="data 2 Here" name="data2" style="width:200px;height:40px;"></textarea>
<textarea placeholder="fild not required" name="data3" style="width:200px;height:40px;"></textarea>
<br>
<input id=bouton1 type="button" onclick="javascript:generateTable()" value="GenerateTable"/>
<div id="excel_table1"></div>
<!--------- script that get the data from cells to show it in <H2> -->
<script type="text/javascript">
function buttonTEST()
{
$('#displayCell').html("");
var x = document.getElementById('excel_table1').getElementsByTagName('tr')[0].cells[1].innerHTML;
var y = document.getElementById('excel_table1').getElementsByTagName('tr')[0].cells[2].innerHTML;
if (y === undefined) {
y = " ";
}
document.getElementById('displayCell').innerHTML = x +" "+ y;
}
</script>
<br/><br/>
<h2 id="displayCell"></h2>
<br/><br/>
<input id="Button2" type="button" onclick="buttonTEST()" value="TEST ME"/>As you can see, if you generate a table with only to columns (which is supposed/needs to happen sometimes), we get this error from the console because we're trying to get "innerHTML" from a undefined:
index.html:120 Uncaught TypeError: Cannot read property 'innerHTML' of undefined
A little specification: When that cell is=undefined , I need it to stay undefined, I only want to change the fact that my var y also becomes undefined.
So I thought that changing the value of var y (and not the value of that cell, otherwise, the 3rd column, supposed to be empty, would be created just because of an blank space) to a blank space would resolve the problem, but I don't seem to get it right (write it in a correct manner).
Any ideas?
So here's the answer that worked for me:
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
</head>
<body><center>
</center></body>
<!--------- script that generates my table from text areas -->
<script>
function generateTable() {
$('#excel_table1').html("");
var n=1;
var rows=[];
var lng=0;
var maxligne=0;
$('textarea').each(function(){
var data = $(this).val();
if (data !=''){
var rowData = data.split("\n");
rows[n] = rowData;
lng = rowData.length;
if(lng > maxligne)
{
maxligne=lng
}
n++;
}
}
)
var table = $('<table />');
k=0;
while (k < maxligne) {
var row = $('<tr />');
for(var i = 1; i < rows.length; i++)
{
var singleRow = rows[i];
if(singleRow[k]!= undefined){
row.append('<td>'+singleRow[k]+'</td>')
} else {
row.append('<td></td>')
}
}
table.append(row);
k++;
}
$('#excel_table1').append(table);
}
</script>
<textarea placeholder="data 2 Here" name="data1" style="width:100px;height:40px;"></textarea>
<textarea placeholder="data 2 Here" name="data2" style="width:200px;height:40px;"></textarea>
<textarea placeholder="fild not required" name="data3" style="width:200px;height:40px;"></textarea>
<br>
<input id=bouton1 type="button" onclick="javascript:generateTable()" value="GenerateTable"/>
<div id="excel_table1"></div>
<!--------- script that get the data from cells to show it in <H2> -->
<script type="text/javascript">
function buttonTEST()
{
$('#displayCell').html("");
var x = $('#excel_table1 tr:nth-child(1) td:nth-child(2)').html();
var y = $('#excel_table1 tr:nth-child(1) td:nth-child(3)').html();
if (y ===undefined)
{document.getElementById('displayCell').innerHTML = x ;}
else
{document.getElementById('displayCell').innerHTML = x +" "+ y;}
}
</script>
<br/><br/>
<h2 id="displayCell"></h2>
<br/><br/>
<input id="Button2" type="button" onclick="buttonTEST()" value="TEST ME"/>