Add config option to transform values before dinamic typing (#505)

papaparse.js

@@ -205,6 +205,8 @@
 		}
 		_config.dynamicTyping = dynamicTyping;
 
+		_config.transform = isFunction(_config.transform) ? _config.transform : false;
+
 		if (_config.worker && Papa.WORKERS_SUPPORTED)
 		{
 			var w = newWorker();
@@ -1087,7 +1089,7 @@
 			if (needsHeaderRow())
 				fillHeaderFields();
 
-			return applyHeaderAndDynamicTyping();
+			return applyHeaderAndDynamicTypingAndTransformation();
 		}
 
 		function needsHeaderRow()
@@ -1139,9 +1141,9 @@
 			return value;
 		}
 
-		function applyHeaderAndDynamicTyping()
+		function applyHeaderAndDynamicTypingAndTransformation()
 		{
-			if (!_results || (!_config.header && !_config.dynamicTyping))
+			if (!_results || (!_config.header && !_config.dynamicTyping && !_config.transform))
 				return _results;
 
 			for (var i = 0; i < _results.data.length; i++)
@@ -1157,6 +1159,9 @@
 					if (_config.header)
 						field = j >= _fields.length ? '__parsed_extra' : _fields[j];
 
+					if (_config.transform)
+						value = _config.transform(value,field);
+
 					value = parseDynamic(field, value);
 
 					if (field === '__parsed_extra')

tests/test-cases.js

@@ -872,6 +872,19 @@ var PARSE_TESTS = [
 			errors: []
 		}
 	},
+	{
+		description: "Custom transform function is applied to values",
+		input: 'A,B,C\r\nd,e,f',
+		config: {
+			transform: function(value) {
+				return value.toLowerCase();
+			}
+		},
+		expected: {
+			data: [["a","b","c"], ["d","e","f"]],
+			errors: []
+		}
+	},
 	{
 		description: "Blank line at beginning",
 		input: '\r\na,b,c\r\nd,e,f',