Added new plugin for automatic detection of negative currency

Name: brackets-negative
Summary: Detect data of currency type with a leading currency symbol as well at detect two types of negative number formatting

sorting/brackets-negative.js

@@ -0,0 +1,42 @@
+/**
+ * This plug-in will add automatic negative currency detection for currency columns to
+ * DataTables. Note that only $, c, £ and € symbols are detected with this code,
+ * This plugin has also been updated to automatically detect negative values either those
+ * using '-' as well as numbers using '()' to specify negatives.
+ * This plugin also includes automatic type detection
+ *
+ *  @name brackets-negative
+ *  @summary Detect data of currency type with a leading currency symbol as well at detect two types of negative number formatting
+ *  @author [Tom Buckle](http://sprymedia.co.uk)
+ */
+(function(){
+	// Change this list to the valid characters you want to be detected
+	var validChars = "$£€c" + "0123456789" + ".-,()'";
+	// Init the regex just once for speed - it is "closure locked"
+	var
+	str = jQuery.fn.dataTableExt.oApi._fnEscapeRegex( validChars ),re = new RegExp('[^'+str+']');
+	$.fn.dataTableExt.aTypes.unshift(
+		function ( data )
+		{
+			if ( typeof data !== 'string' || re.test(data) ) {
+				return null;
+			}
+			return 'currency';
+		}
+	);
+	$.fn.dataTable.ext.type.order['currency-pre'] = function ( data ) {
+		//Check if its in the proper format
+		if(data.match(/[\()]/g)){
+			if( data.match(/[\-]/g) !== true){
+				//It matched - strip out parentheses & any characters we dont want and append - at front
+				data = '-' + data.replace(/[\$£€c\(\),]/g,'');
+			}else{
+				//Already has a '-' so just strip out non-numeric charactors exluding '-'
+				data = data.replace(/[^\d\-\.]/g,'');
+			}
+		}else{
+			data = data.replace(/[\$£€\,]/g,'');
+		}
+		return parseInt( data, 10 );
+	};
+}());