Added function to get value type associated with a key

pynetworktables2js/js/networktables.js

@@ -100,6 +100,9 @@ var NetworkTables = new function () {
 
 	// contents of everything in NetworkTables that we know about
 	var ntCache = new d3_map();
+
+	// value types of all the contents in Networktables that we know about
+	var ntTypeCache = new d3_map();
 
 	//
 	// NetworkTables JS API
@@ -225,6 +228,24 @@ var NetworkTables = new function () {
 		else
 			return val;
 	};
+
+	/**
+		Returns the value type that the key maps to. If the websocket is not
+	    open, this will always return null.
+
+	    :param key: A networktables key
+	    :returns: value type associated with key if present or ``undefined``
+
+			.. warning:: This may not return correct results when the websocket 
+									 is not connected
+    */
+	this.getValueType = function(key) {
+		var type = ntTypeCache.get(key);
+		if (type === undefined)
+			return null;
+		else
+			return type;
+	}
 
 	// returns null if robot is not connected, string otherwise
 	this.getRobotAddress = function() {
@@ -338,8 +359,10 @@ var NetworkTables = new function () {
 					var key = data['k'];
 					var value = data['v'];
 					var isNew = data['n'];
+					var type = data['t'];
 
 					ntCache.set(key, value);
+					ntTypeCache.set(key, type);
 
 					// notify global listeners
 					for (var i in globalListeners) {

pynetworktables2js/nt_serial.py

@@ -5,6 +5,26 @@
 
 from networktables import NetworkTables
 
+from ntcore.constants import (
+    NT_BOOLEAN,
+    NT_DOUBLE,
+    NT_STRING,
+    NT_RAW,
+    NT_BOOLEAN_ARRAY,
+    NT_DOUBLE_ARRAY,
+    NT_STRING_ARRAY,
+)
+
+_nt_type_dict = {
+    NT_BOOLEAN: "NT_BOOLEAN",
+    NT_DOUBLE: "NT_DOUBLE",
+    NT_STRING: "NT_STRING",
+    NT_RAW: "NT_RAW",
+    NT_BOOLEAN_ARRAY: "NT_BOOLEAN_ARRAY",
+    NT_DOUBLE_ARRAY: "NT_DOUBLE_ARRAY",
+    NT_STRING_ARRAY: "NT_STRING_ARRAY",
+}
+
 __all__ = ["NTSerial"]
 
 
@@ -35,7 +55,8 @@ def _send_update(self, data):
 
     def _nt_on_change(self, key, value, isNew):
         """NetworkTables global listener callback"""
-        self._send_update({"k": key, "v": value, "n": isNew})
+        value_type = _nt_type_dict[NetworkTables.getEntry(key).getType()]
+        self._send_update({"k": key, "v": value, "n": isNew, "t": value_type})
 
     # NetworkTables connection listener callbacks
     def _nt_connected(self, connected, info):