DataTables

Hello,

the problem:
we need to highlight the cells content based on the content of the table. lets say a hidden column contains a flag and based on the flag we highlight the other column in a predefined color.

the approach:
it seems that aoColumnsDefs -> fnRender function is the most continent for highlighting. in the function we would read the data in the hidden cells and generate cell content or apply appropriate styling for the cell being rendered.
however, this did not work well for us. the table cell itself (td element) has margins/paddings set and whatever colored markup we generate inside the cell, it always has some white border around. the best solution would be to apply styles to then td element that is being rendered, but the element is not available in the fnRender function.

the solution:
we solve the issue by adjusting the datatables code and adding the td element to the parameter object for fnRender function.
here are the snippets from modified jquery,datatables.js (Version: 1.7.6)
note: the inserts are wrapped in with "ADS" keyword

start at line: 1842

		this.fnUpdate = function( mData, mRow, iColumn, bRedraw, bAction )
		{
...
				if ( oSettings.aoColumns[iColumn].fnRender !== null )
				{
//ADS: Expose TD node to fnRender var iVisCol = _fnColumnIndexToVisible( oSettings, iColumn );
var tdNode;
if ( iVisCol !== null )
{
	tdNode = oSettings.aoData[iRow].nTr.getElementsByTagName('td')[iVisCol];
}
else
{
	tdNode = oSettings.aoData[iRow]._anHidden[iColumn];
}
//:ADS

					sDisplay = oSettings.aoColumns[iColumn].fnRender( {
						"iDataRow": iRow,
						"iDataColumn": iColumn,
						"aData": oSettings.aoData[iRow]._aData,
						"oSettings": oSettings,
						"nTd": tdNode
					} );
					

...

					if ( oSettings.aoColumns[i].fnRender !== null )
					{
//ADS: Expose TD node to fnRender var iVisCol = _fnColumnIndexToVisible( oSettings, iColumn );
var tdNode;
if ( iVisCol !== null )
{
	tdNode = oSettings.aoData[iRow].nTr.getElementsByTagName('td')[iVisCol];
}
else
{
	tdNode = oSettings.aoData[iRow]._anHidden[i];
}
//:ADS

						sDisplay = oSettings.aoColumns[i].fnRender( {
							"iDataRow": iRow,
							"iDataColumn": i,
							"aData": oSettings.aoData[iRow]._aData,
							"oSettings": oSettings,
							"nTd": tdNode
						} );

...

				if ( typeof oSettings.aoColumns[i].fnRender == 'function' )
				{
					var sRendered = oSettings.aoColumns[i].fnRender( {
							"iDataRow": iThisIndex,
							"iDataColumn": i,
							"aData": aData,
							"oSettings": oSettings,
//ADS: Expose TD node to fnRender 							"nTd": nTd
//:ADS
						} );
					nTd.innerHTML = sRendered;
					if ( oSettings.aoColumns[i].bUseRendered )

...

						/* Rendering */
						if ( bRender )
						{
							sRendered = oSettings.aoColumns[iColumn].fnRender( {
									"iDataRow": iRow,
									"iDataColumn": iColumn,
									"aData": oSettings.aoData[iRow]._aData,
									"oSettings": oSettings,
//ADS: Expose TD node to fnRender 									"nTd": nCell
//:ADS
								} );
							nCell.innerHTML = sRendered;
							if ( oSettings.aoColumns[iColumn].bUseRendered )

if you see a better way to access td element, your comments are appreciated.
if not, I hope to see this (or similar) fixes to be incorporated to the next releases.

Thanks,
Andrew.