javascript - jQuery DataTables Filtering for Specific Columns Only

Question

I am using the jQuery plugin DataTables (http://datatables.net) for pagination, search capabilities and filtering.

There is a filter function (http://datatables.net/release-datatables/examples/api/multi_filter_select.html) that places form select elements for each column.

My issue is that I don't want the filter select elements for every column, only some. I've modified the original code as I want Yes/No filtering only, and my first column contains user names.

How do I remove the form select element from the first column?

JavaScript:

<script type="text/javascript">

$(document).ready(function() {

(function($) {
/*
 * Function: fnGetColumnData
 * Purpose:  Return an array of table values from a particular column.
 * Returns:  array string: 1d data array
 * Inputs:   object:oSettings - dataTable settings object. This is always the last argument past to the function
 *           int:iColumn - the id of the column to extract the data from
 *           bool:bUnique - optional - if set to false duplicated values are not filtered out
 *           bool:bFiltered - optional - if set to false all the table data is used (not only the filtered)
 *           bool:bIgnoreEmpty - optional - if set to false empty values are not filtered from the result array
 * Author:   Benedikt Forchhammer <b.forchhammer /AT mind2.de>
 */
$.fn.dataTableExt.oApi.fnGetColumnData = function ( oSettings, iColumn, bUnique, bFiltered, bIgnoreEmpty ) {
    // check that we have a column id
    if ( typeof iColumn == "undefined" ) return new Array();

    // by default we only want unique data
    if ( typeof bUnique == "undefined" ) bUnique = true;

    // by default we do want to only look at filtered data
    if ( typeof bFiltered == "undefined" ) bFiltered = true;

    // by default we do not wany to include empty values
    if ( typeof bIgnoreEmpty == "undefined" ) bIgnoreEmpty = true;

    // list of rows which we're going to loop through
    var aiRows;

    // use only filtered rows
    if (bFiltered == true) aiRows = oSettings.aiDisplay;
    // use all rows
    else aiRows = oSettings.aiDisplayMaster; // all row numbers

    // set up data array   
    var asResultData = new Array();

    for (var i=0,c=aiRows.length; i<c; i++) {
        iRow = aiRows[i];
        var aData = this.fnGetData(iRow);
        var sValue = aData[iColumn];

        // ignore empty values?
        if (bIgnoreEmpty == true && sValue.length == 0) continue;

        // ignore unique values?
        else if (bUnique == true && jQuery.inArray(sValue, asResultData) > -1) continue;

        // else push the value onto the result data array
        else asResultData.push(sValue);
    }

    return asResultData;
}}(jQuery));


function fnCreateSelect( aData )
{
    return '<select><option value="">Select</option><option value="Yes">Yes</option><option value="No">No</option></select>';
}

   var oTable = $('#results').dataTable({
         "sDom": '<<"filters"f><"clear"><"top"Tp><"clear">rt<"bottom"il>>',
         "iDisplayLength": 5,
         "sPaginationType": "full_numbers",
         "bSortCellsTop": true,
         "oLanguage": {
                    "sSearch": "Search all columns:"
          },
         "aoColumns": [
                null,
                { "sType": "title-string" },
                { "sType": "title-string" },
                { "sType": "title-string" },
                { "sType": "title-string" }
            ],
        "oTableTools": {
            "sSwfPath": "../../scripts/TableTools/copy_cvs_xls_pdf.swf" 
        }         
    });  


 /* Add a select menu for each TH element in the table footer */
    $("thead #filter td").each( function ( i ) {
        this.innerHTML = fnCreateSelect( oTable.fnGetColumnData(i) );
        $('select', this).change( function () {
            oTable.fnFilter( $(this).val(), i );
        } );
    } );    
} );
</script>

HTML:

<table id="results" class="display">
    <thead>
        <tr id="labels">
            <th>1</th>
            <th>2</th>
            <th>3</th>
            <th>4</th>
            <th>5?</th>
        </tr>
        <tr id="filter">
            <td>1</td>
            <td>2</td>
            <td>3</td>
            <td>4</td>
            <td>5?</td>
        </tr>
    </thead>
    <tbody>
    ...
    </tbody>
</table>

Answer 1

You can modify your selector to ignore the first <td> element. The index of each matched element should be 1 less than the corresponding column index.

/* Add a select menu for each TH element except the first in the table footer */
$("thead #filter td:not(:eq(0))").each( function ( i ) {
    var columnIndex = i + 1;
    this.innerHTML = fnCreateSelect( oTable.fnGetColumnData(columnIndex) );
    $('select', this).change( function () {
        oTable.fnFilter( $(this).val(), columnIndex );
    } );
});

If you wanted to be able to specify the column indexes for which you wanted a filter, one way would be to do something like

var filterIndexes = [3, 4];
$('td', '#filter').each( function ( i ) {
    if ($.inArray(i, filterIndexes) != -1) {
        this.innerHTML = fnCreateSelect( oTable.fnGetColumnData(i) );
        $('select', this).change( function () {
            oTable.fnFilter( $(this).val(), i );
        });
    }
});

Or, if you wanted to control filters by adding a class .filter to any <th> element whose column you wanted to filter, you could do something like

$('th', '#labels').each( function(i) {
    if ($(this).hasClass( 'filter' )) {
        $('td', '#filter').eq(i)
          .html( fnCreateSelect(oTable.fnGetColumnData(i)) )
          .find('select')
          .change(function () { oTable.fnFilter($(this).val(), i); });
    }
});    

Not tested, but you get the idea :)