fix(reload): plugins are now reloaded instantly after config change

lib/plugins.js

@@ -11,13 +11,22 @@ var POLLING_RATE = 60 * 1000; // poll each minute
 
 var db = null;
 
+
 var tickerPlugin = null;
 var traderPlugin = null;
 var walletPlugin = null;
 var idVerifierPlugin = null;
 
+var currentlyUsedPlugins = {
+  ticker: null,
+  transfer: null,
+  trader: null,
+  idVerifier: null
+};
+
+
 var cachedConfig = null;
-var deviceCurrency = 'USD'; // Can 'USD' be set as default?
+var deviceCurrency = 'USD';
 
 var lastBalances = null;
 var lastRates = {};
@@ -93,56 +102,65 @@ function loadPlugin(name, config) {
   return plugin;
 }
 
+function loadOrConfigPlugin(pluginHandle, pluginType, currency, onChangeCb) {
+  var currentName = cachedConfig.exchanges.plugins.current[pluginType];
+  var pluginChanged = currentlyUsedPlugins[pluginType] !== currentName;
+
+  if (currentName) { // some plugins may be disabled
+    var pluginConfig = cachedConfig.exchanges.plugins.settings[currentName] || {};
+
+    if (currency) pluginConfig.currency = currency;
+
+    if (pluginHandle && !pluginChanged) pluginHandle.config(pluginConfig);
+    else pluginHandle = loadPlugin(currentName, pluginConfig);
+  }
+
+  if (typeof onChangeCb === 'function') onChangeCb(pluginHandle, currency);
+
+  return pluginHandle;
+}
+
 
 exports.configure = function configure(config) {
   if (config.exchanges.settings.lowBalanceMargin < 1) {
     throw new Error('`settings.lowBalanceMargin` has to be >= 1');
   }
 
-  deviceCurrency = config.exchanges.settings.currency;
-  var plugins = config.exchanges.plugins;
-
-  // [required] configure (or load) ticker
-  var tickerName = plugins.current.ticker;
-  var tickerConfig = plugins.settings[tickerName] || {};
-  tickerConfig.currency = deviceCurrency;
-
-  if (tickerPlugin) tickerPlugin.config(tickerConfig);
-  else tickerPlugin = loadPlugin(tickerName, tickerConfig);
-
-
-  // [required] configure (or load) wallet
-  var walletName = plugins.current.transfer;
-  var walletConfig = plugins.settings[walletName] || {};
-
-  if (walletPlugin) walletPlugin.config(walletConfig);
-  else walletPlugin = loadPlugin(walletName, walletConfig);
-
-
-  // [optional] configure (or load) trader
-  var traderName = plugins.current.trade;
-  if (traderName) { // traderPlugin may be disabled
-    var traderConfig = plugins.settings[traderName] || {};
-
-    if (traderPlugin) traderPlugin.config(traderConfig);
-    else traderPlugin = loadPlugin(traderName, traderConfig);
-  }
-
-
-  // [optional] ID Verifier
-  var verifierName = plugins.current.idVerifier;
-  if (verifierName) { // idVerifierPlugin may be disabled
-    var verifierConfig = plugins.settings[verifierName] || {};
-
-    if (idVerifierPlugin) idVerifierPlugin.config(verifierConfig);
-    else idVerifierPlugin = loadPlugin(verifierName, verifierConfig);
-  }
-
-
   cachedConfig = config;
 
-  pollBalance();
+  // TICKER [required] configure (or load)
-  pollRate();
+  loadOrConfigPlugin(
+    tickerPlugin,
+    'ticker',
+    config.exchanges.settings.currency, // device currency
+    function onTickerChange(newTicker, currency) {
+      tickerPlugin = newTicker;
+      pollRate();
+    }
+  );
+
+  // WALLET [required] configure (or load)
+  loadOrConfigPlugin(
+    walletPlugin,
+    'transfer',
+    null,
+    function onWalletChange(newWallet) {
+      walletPlugin = newWallet;
+      pollBalance();
+    }
+  );
+
+  // TRADER [optional] configure (or load)
+  traderPlugin = loadOrConfigPlugin(
+    traderPlugin,
+    'trade'
+  );
+
+  // ID VERIFIER [optional] configure (or load)
+  idVerifierPlugin = loadOrConfigPlugin(
+    idVerifierPlugin,
+    'idVerifier'
+  );
 };
 exports.getCachedConfig = function getCachedConfig() {
   return cachedConfig;
@@ -298,7 +316,7 @@ function pollBalance(callback) {
 }
 
 function pollRate(callback) {
-  logger.debug('polling for rates');
+  logger.debug('polling for rates (' + tickerPlugin.NAME + ')');
 
   tickerPlugin.ticker(deviceCurrency, function(err, resRates) {
     if (err) {