Datatables: Cannot read property 'mData' of undefined

I have a issue with Datatables. I also went through this link which didnt yield me any result.I have inlcuded all the prerequisites where am parsing data directly into the DOM. Kindly help me to fix this issue.

Script

$(document).ready(function() {
  $('.viewCentricPage .teamCentric').dataTable({
    "bJQueryUI": true,
    "sPaginationType": "full_numbers",
    "bPaginate": false,
    "bFilter": true,
    "bSort": true,
    "aaSorting": [
      [1, "asc"]
    ],
    "aoColumnDefs": [{
      "bSortable": false,
      "aTargets": [0]
    }, {
      "bSortable": true,
      "aTargets": [1]
    }, {
      "bSortable": false,
      "aTargets": [2]
    }],
  });
});


ANSWERS:


FYI dataTables requires a well formed table. It must contain <thead> and <tbody> tags, otherwise it throws this error. Also check to make sure all your rows including header row have the same number of columns.

The following will throw error (no <thead> and <tbody> tags)

<table id="sample-table">
    <tr>
        <th>title-1</th>
        <th>title-2</th>
    </tr>
    <tr>
        <td>data-1</td>
        <td>data-2</td>
    </tr>
</table>

The following will also throw an error (unequal number of columns)

<table id="sample-table">
    <thead>
        <tr>
            <th>title-1</th>
            <th>title-2</th>
        </tr>
    </thead>
    <tbody>
        <tr>
            <td>data-1</td>
            <td>data-2</td>
            <td>data-3</td>
        </tr>
    </tbody>
</table>

For more info read more here


A common cause for Cannot read property 'fnSetData' of undefined is the mismatched number of columns, like in this erroneous code:

<thead>
    <tr>                <!-- tr required -->
        <th>Rep</th>
        <th>Titel</th>
                        <!-- th missing here -->
    </tr>
</thead>
<tbody>
    <tr>
        <td>Rep</td>
        <td>Titel</td>
        <td>Missing corresponding th</td>
    </tr>
</tbody>

While the following code with one <th> per <td> (number of columns must match) works:

<thead>
    <tr>
        <th>Rep</th>
        <th>Titel</th>
        <th>Added th</th>
    </tr>
</thead>
<tbody>
    <tr>
        <td>Rep</td>
        <td>Titel</td>
        <td>th now present</td>
    </tr>
</tbody>

The error also appears when using a well-formed thead with a colspan but without a second row.

For a table with 7 colums, the following does not work and we see "Cannot read property 'mData' of undefined" in the javascript console:

<thead>
    <tr>
        <th>Rep</th>
        <th>Titel</th>
        <th colspan="5">Download</th>
    </tr>
</thead>

While this works:

<thead>
    <tr>
        <th rowspan="2">Rep</th>
        <th rowspan="2">Titel</th>
        <th colspan="5">Download</th>
    </tr>
    <tr>
        <th>pdf</th>
        <th>nwc</th>
        <th>nwctxt</th>
        <th>mid</th>
        <th>xml</th>
    </tr>
</thead>

I had this same problem using DOM data in a Rails view created via the scaffold generator. By default the view omits th elements for the last three columns (which contain links to show, hide, and destroy records). I found that if I added in titles for those columns in a th element within the thead that it fixed the problem.

I can't say if this is the same problem you're having since I can't see your html. If it is not the same problem, you can use the chrome debugger to figure out which column it is erroring out on by clicking on the error in the console (which will take you to the code it is failing on), then adding a conditional breakpoint (col==undefined). When it stops you can check the variable i to see which column it is currently on which can help you figure out what is different about that column from the others. Hope that helps!

debugging mData error


This can also occur if you have table arguments for things like 'aoColumns':[..] which don't match the correct number of columns. Problems like this can commonly occur when copy pasting code from other pages to quick start your datatables integration.

Example:

This won't work:

<table id="dtable">
    <thead>
        <tr>
            <th>col 1</th>
            <th>col 2</th>
        </tr>
    </thead>
    <tbody>
        <td>data 1</td>
        <td>data 2</td>
    </tbody>
</table>
<script>
        var dTable = $('#dtable');
        dTable.DataTable({
            'order': [[ 1, 'desc' ]],
            'aoColumns': [
                null,
                null,
                null,
                null,
                null,
                null,
                {
                    'bSortable': false
                }
            ]
        });
</script>

But this will work:

<table id="dtable">
    <thead>
        <tr>
            <th>col 1</th>
            <th>col 2</th>
        </tr>
    </thead>
    <tbody>
        <td>data 1</td>
        <td>data 2</td>
    </tbody>
</table>
<script>
        var dTable = $('#dtable');
        dTable.DataTable({
            'order': [[ 0, 'desc' ]],
            'aoColumns': [
                null,
                {
                    'bSortable': false
                }
            ]
        });
</script>

You have to remove your colspan and the number of th and td needs to match.


In my case, and using ASP.NET GridView, UpdatePanel and with DropDownList (with Chosen plugin where I reset value to zero using a Javascript line), I got this error and tried everything with no hope for days. The problem was that the code of my dropdown in code behind was as follows and when I select a value twice to apply its action to selected grid rows I get that error. I thought for days it's a Javascript issue (again, in my case) and finally the fix was giving zero for the drowpdown value with the update process:

  private void ddlTasks_SelectedIndexChanged(object sender, System.EventArgs e)
  {
     if (ddlTasks.SelectedValue != 0) {
        ChangeStatus(ddlTasks.SelectedValue);
        ddlTasks.SelectedValue = "0"; //// **This fixed my issue**
     }

     dvItemsGrid.DataSource = CreateDatasource();
     dvItemsGrid.DataBind();
     dvItemsGrid.UseAccessibleHeader = true;
     dvItemsGrid.HeaderRow.TableSection = TableRowSection.TableHeader;

  }

This was my fault:

     $('#<%= DropDownList.ClientID%>').val('0').trigger("chosen:updated").chosen();

I had encountered the same issue but I was generating table Dynamically. In my case, my table had missing <thead> and <tbody> tags.

here is my code snippet if it helped somebody

   //table string
   var strDiv = '<table id="tbl" class="striped center responsive-table">';

   //add headers
   var strTable = ' <thead><tr id="tableHeader"><th>Customer Name</th><th>Customer Designation</th><th>Customer Email</th><th>Customer Organization</th><th>Customer Department</th><th>Customer ContactNo</th><th>Customer Mobile</th><th>Cluster Name</th><th>Product Name</th><th> Installed Version</th><th>Requirements</th><th>Challenges</th><th>Future Expansion</th><th>Comments</th></tr> </thead> <tbody>';


  //add data
  $.each(data, function (key, GetCustomerFeedbackBE) {
                            strTable = strTable + '<tr><td>' + GetCustomerFeedbackBE.StrCustName + '</td><td>' + GetCustomerFeedbackBE.StrCustDesignation + '</td><td>' + GetCustomerFeedbackBE.StrCustEmail + '</td><td>' + GetCustomerFeedbackBE.StrCustOrganization + '</td><td>' + GetCustomerFeedbackBE.StrCustDepartment + '</td><td>' + GetCustomerFeedbackBE.StrCustContactNo + '</td><td>' + GetCustomerFeedbackBE.StrCustMobile + '</td><td>' + GetCustomerFeedbackBE.StrClusterName + '</td><td>' + GetCustomerFeedbackBE.StrProductName + '</td><td>' + GetCustomerFeedbackBE.StrInstalledVersion + '</td><td>' + GetCustomerFeedbackBE.StrRequirements + '</td><td>' + GetCustomerFeedbackBE.StrChallenges + '</td><td>' + GetCustomerFeedbackBE.StrFutureExpansion + '</td><td>' + GetCustomerFeedbackBE.StrComments + '</td></tr>';
                        });

//add end of tbody
 strTable = strTable + '</tbody></table>';

//insert table into a div                 
   $('#divCFB_D').html(strDiv);
   $('#tbl').html(strTable);


    //finally add export buttons 
   $('#tbl').DataTable({
                            dom: 'Bfrtip',
                            buttons: [
                                'copy', 'csv', 'excel', 'pdf', 'print'
                            ]
                        });

In addition to inconsistent and numbers, a missing item inside datatable scripts columns part can cause this too. Correcting that fixed my datatables search bar.

I'm talking about this part;

"columns": [
  null,
  .
  .
  .
  null
           ],

I struggled with this error till I was pointed that this part had one less "null" than my total thead count.


I found some "solution".

This code doesn't work:

<table>
<thead>
    <tr>
        <th colspan="3">Test</th>
    </tr>
</thead>
<tbody>
    <tr>
        <td>1</td>
        <td>2</td>
        <td>3</td>
    </tr>
</tbody>

But this is ok:

<table>
<thead>
    <tr>
        <th colspan="2">Test</th>
        <th></th>
    </tr>
</thead>
<tbody>
    <tr>
        <td>1</td>
        <td>2</td>
        <td>3</td>
    </tr>
</tbody>

I think, that the problem is, that the last TH can't have attribute colspan.



 MORE:


 ? jQuery DataTables: Uncaught TypeError: Cannot read property 'mData' of undefined
 ? Uncaught TypeError: Cannot read property 'aDataSort' of undefined
 ? Datatables plugin error Uncaught TypeError: Cannot read property 'mData' of undefined
 ? Uncaught TypeError: Cannot read property 'mData' of undefined
 ? DataTables: Uncaught TypeError: Cannot read property 'mData' of undefined
 ? Uncaught TypeError: Cannot read property 'mData' of undefined at jquery.dataTables.yadcf.min.js
 ? Uncaught TypeError: Cannot read property 'next_page' of undefined
 ? Uncaught TypeError: Cannot read property 'textContent' of undefined
 ? Vue Resource - Post multiple data
 ? Vue Resource - Post multiple data