jquery datatables: adding extra column

Question

Scenario

I am using datatables (@version 1.9.4) for the first time to display data to the user. I succeed in retrieving the data via ajax and in binding them to the datatable.

Now I want to add extra columns to let the user process the records. For semplicity sake, the aim is to add a button with an onclick handler that retrieve the data of the 'clicked' record.

In my plan I would bind the json item corresponding to the 'clicked' record to the onclick handler.

Till now, if I add an additional TH for the action column to the DOM, an error occurs from datatables code:

Requested unknown parameter '5' from data source for row 0

Question

How to set custom columns? How to fill their content with HTML?

---

Here is my actual config.

HTML

<table id="tableCities">
    <thead>
        <tr>
            <th>country</th>
            <th>zip</th>
            <th>city</th>
            <th>district code</th>
            <th>district description</th>
            <th>actions</th>
        </tr>
    </thead>
    <tbody></tbody>
</table>

Javascript

$('#tableCities').dataTable({
    "bPaginate": true,
    "bLengthChange": false,
    "bFilter": true,
    "bSort": true,
    "bInfo": false,
    "bAutoWidth": true
    , "bJQueryUI": true
    , "bProcessing": true
    , "bServerSide": true
    , "sAjaxSource": "../biz/GetCitiesByZip.asp?t=" + t
});

Sample Json result

{
    "aaData":
    [
        [
            "IT",
            "10030",
            "VILLAREGGIA",
            "TO",
            "Torino"
        ],
        [
            "IT",
            "10030",
            "VISCHE",
            "TO",
            "Torino"
        ]
    ],
    "iTotalRecords": 2,
    "iTotalDisplayRecords": 2,
    "iDisplayStart": 0,
    "iDisplayLength": 2
}

Edit

Daniel is right. The solution is to set up the custom column in the aoColumnDefs, specifying the mData and the mRender properties. In particular mRender lets to define custom html and javascript.

/* inside datatable initialization */
, "aoColumnDefs": [
   {
        "aTargets": [5],
        "mData": null,
        "mRender": function (data, type, full) {
            return '<a href="#" onclick="alert(\''+ full[0] +'\');">Process</a>';
        }
    }
 ]

Answer 1

You can define your columns in a different way like this

"aoColumns": [
        null,
        null,
        null,
        null,
        null,
        { "mData": null }
    ]

or this

"aoColumnDefs":[
    {
        "aTargets":[5],
        "mData": null
    }
]

Here some docs Columns

Take a look at this DataTables AJAX source example - null data source for a column

Note that prior to DataTables 1.9.2 mData was called mDataProp. The name change reflects the flexibility of this property and is consistent with the naming of mRender. If 'mDataProp' is given, then it will still be used by DataTables, as it automatically maps the old name to the new if required.

Another solution/workaround could be adding that '5' parameter...

For example adding extra "" to each row

like this:

    [
        "IT",
        "10030",
        "VILLAREGGIA",
        "TO",
        "Torino",
        ""
    ],
    [
        "IT",
        "10030",
        "VISCHE",
        "TO",
        "Torino",
        ""
    ]