Currency Sorting Algorithm Bugged on Null Data Values

adamterlson

The logic as it's posted (given below for reference) bombs on null data. The issue is that the null data makes the local X and Y variables get assigned to [0], while the next block of code attempts to run ".substring" against it. This will obviously fail.

Here is a new version that works. I additionally added handling for null data (which could be removed if desired, but I needed it):

[code]
jQuery.fn.dataTableExt.oSort['currency-asc'] = function (a, b)
{
/* Remove any commas (assumes that if present all strings will have a fixed number of d.p) */
var x = (a == "-" || a == "") ? 0 : a.replace(/,/g, "").substring(1); //Doesn't call .substring when it's null data.
var y = (b == "-" || b == "") ? 0 : b.replace(/,/g, "").substring(1);

/* Parse and return */
x = parseFloat(x);
y = parseFloat(y);
return x - y;
};

jQuery.fn.dataTableExt.oSort['currency-desc'] = function (a, b)
{
/* Remove any commas (assumes that if present all strings will have a fixed number of d.p) */
var x = (a == "-" || a == "") ? 0 : a.replace(/,/g, "").substring(1);
var y = (b == "-" || b == "") ? 0 : b.replace(/,/g, "").substring(1);

/* Parse and return */
x = parseFloat(x);
y = parseFloat(y);
return y - x;
};
[/code]

Here is the old version for reference:

[code]
jQuery.fn.dataTableExt.oSort['currency-asc'] = function(a,b) {
/* Remove any commas (assumes that if present all strings will have a fixed number of d.p) */
var x = a == "-" ? 0 : a.replace( /,/g, "" );
var y = b == "-" ? 0 : b.replace( /,/g, "" );

/* Remove the currency sign */
x = x.substring( 1 ); //Bombs -- Cannot call .substring on a number.
y = y.substring( 1 ); //Bombs -- Cannot call .substring on a number.

/* Parse and return */
x = parseFloat( x );
y = parseFloat( y );
return x - y;
};

jQuery.fn.dataTableExt.oSort['currency-desc'] = function(a,b) {
/* Remove any commas (assumes that if present all strings will have a fixed number of d.p) */
var x = a == "-" ? 0 : a.replace( /,/g, "" );
var y = b == "-" ? 0 : b.replace( /,/g, "" );

/* Remove the currency sign */
x = x.substring( 1 ); //Bombs -- Cannot call .substring on a number.
y = y.substring( 1 ); //Bombs -- Cannot call .substring on a number.

/* Parse and return */
x = parseFloat( x );
y = parseFloat( y );
return y - x;
};

[/code]

allan

When you say null data, you mean an empty string? It looks like the above code would probably still give an error on a null.

Allan

adamterlson

Yes, sorry, I mean "empty" cells. I'm not sure that it's even possible to get null into this function?

victoro

Thanks Adam, worked like a charm.