add ability to configure which columns are dynamically typed

papaparse.js

@@ -193,7 +193,7 @@
 	function CsvToJson(_input, _config)
 	{
 		_config = _config || {};
-		_config.dynamicTyping = _config.dynamicTyping || false;
+		_config.dynamicTyping = new DynamicTypingConfig(_config.dynamicTyping);
 
 		if (_config.worker && Papa.WORKERS_SUPPORTED)
 		{
@@ -415,6 +415,24 @@
 		}
 	}
 
+	function DynamicTypingConfig(config)
+	{
+		this._config = config;
+	}
+	DynamicTypingConfig.prototype.constructor = DynamicTypingConfig;
+	DynamicTypingConfig.prototype.isIncluded = function(field)
+	{
+		if (typeof this._config === 'function')
+		{
+			return this._config(field) === true;
+		}
+		if (typeof this._config === 'object')
+		{
+			return this._config[field] === true;
+		}
+		return !!this._config;
+	};
+
 	/** ChunkStreamer is the base prototype for various streamer implementations. */
 	function ChunkStreamer(config)
 	{
@@ -969,7 +987,7 @@
 
 		function parseDynamic(field, value)
 		{
-			if ((_config.dynamicTyping[field] || _config.dynamicTyping) === true)
+			if (_config.dynamicTyping.isIncluded(field))
 			{
 				if (value === 'true' || value === 'TRUE')
 					return true;

tests/test-cases.js

@@ -693,6 +693,24 @@ var PARSE_TESTS = [
 			}]
 		}
 	},
+	{
+		description: "Dynamic typing by indices can be determined by function",
+		input: '001,002,003',
+		config: { dynamicTyping: function(field) { return (field % 2) === 0; } },
+		expected: {
+			data: [[1, "002", 3]],
+			errors: []
+		}
+	},
+	{
+		description: "Dynamic typing by headers can be determined by function",
+		input: 'A_as_int,B,C_as_int\r\n001,002,003',
+		config: { header: true, dynamicTyping: function(field) { return /_as_int$/.test(field); } },
+		expected: {
+			data: [{"A_as_int": 1, "B": "002", "C_as_int": 3}],
+			errors: []
+		}
+	},
 	{
 		description: "Blank line at beginning",
 		input: '\r\na,b,c\r\nd,e,f',