T. Rex T. Rex - 7 months ago 25
Javascript Question

Cannot read property 'mData' of undefined when using DataTables with colspan

I'm using datatables to display data from the server. Problem is I keep getting an error in the console saying:

datatables.min.js:145 Uncaught TypeError: Cannot read property 'mData' of undefined


I have visited literally every link on the internet the relates to this, but nothing's worked for me.

I have made sure the number of columns are the same in both thead and tbody using colspans.

I'm probably missing something, but after spending quite some time on it, I'd appreciate some help here.

Here's what the code looks like

HTML:

<table id="data-table" class="display table" width="100%">
<thead>
<tr>
<th colspan="4" class="center-align solid-left-border" style="border-bottom: none; text-decoration: underline; text-transform: uppercase; padding: 5px 18px;">
Tier 2 Contributions Report
</th>
</tr>

<tr>
<th class="left-align solid-left-border" style="border-bottom: none; text-decoration: none; text-transform: uppercase; font-weight: normal; font-weight: normal; padding: 5px 18px; font-size: 12.5px">
Employer's FIle No/Registration No:
</th>

<th colspan="3" class="left-align solid-left-border" style="border-bottom: none; font-weight: normal; padding: 5px 18px; font-size: 12.5px; text-transform: uppercase;">
<%= company.getSSNITRegistration() || '-' %>
</th>
</tr>

<tr>
<th class="left-align solid-left-border" style="border-bottom: none; text-decoration: none; text-transform: uppercase; font-weight: normal; padding: 5px 18px; font-size: 12.5px;">
Name of Employer:
</th>

<th colspan="3" class="left-align solid-left-border" style="border-bottom: none; font-weight: normal; padding: 5px 18px; font-size: 12.5px; text-transform: uppercase;">
<%= company.getName() || '-' %>
</th>
</tr>

<tr>
<th class="left-align solid-left-border" style="border-bottom: none; text-decoration: none; text-transform: uppercase; font-weight: normal; padding: 5px 18px; font-size: 12.5px;">
Address of Employer:
</th>

<th colspan="3" class="left-align solid-left-border" style="border-bottom: none; font-weight: normal; padding: 5px 18px; font-size: 12.5px; text-transform: uppercase;">
<%= company.getAddress() || '-' %>
</th>
</tr>


<tr>
<th colspan="4" style="border-bottom: none;"></th>
</tr>
</thead>

<tfoot>
<tr>
<th colspan="2" class="left-align">Totals</th>
<th class="center-align"><%= addCommas(totals.basicSalary) %></th>
<th class="right-align"><%= addCommas(totals.contribution) %></th>
</tr>
</tfoot>

<tbody>
<tr>
<th class="left-align">Social Sec. No.</th>
<th class="left-align">Full Name</th>
<th class="center-align">Basic Salary</th>
<th class="right-align">Contribution (5%)</th>
</tr>

<% employees.forEach(function(employee) { %>
<tr>
<td class="left-align"><%= employee.ssnitNumber %></td>
<td class="left-align"><%= employee.lastName + ', ' + employee.firstName + ' ' + employee.otherNames%></td>
<td class="center-align"><%= addCommas(employee.basicSalary) %></td>
<td class="right-align"><%= addCommas(employee.contribution) %></td>
</tr>
<% }) %>
</tbody>
</table>


JS

$('#data-table').DataTable( {
"bPaginate": true,
"bLengthChange": true,
"bFilter": true,
"bSort": false,
"bInfo": true,
"bAutoWidth": false,
"dom": 'Bfrtip',
"buttons": [
'copy', 'csv', 'excel', 'pdf', 'print'
]

});

Answer

General cause of such problems is

  1. Mismatch between header column and footer columns.

  2. Body elements do not match with header(Number of td in one row should match with <th> in header).

  3. Duplication of table Id.

In your case please move headers(like Social sec no. etc) from <tbody> to <thead>, and also your header and footer is not matching please make them same as I see there is 4 elements in header and only 3 in footer.

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