gistfile1.js

//the pluginSpec from the instrument module
var plugin = {
 name: 'aPLugin',
 spec: {
   'onTransport': {
    'clients' : 'someClient' /*or*/ ['clienta', 'clientb', 'clientc' ...] /*or * if none specified */,
    'action': 'exec:./doSomething'
   },
   'onStats': 
   {
    'clients' : 'someClient' /*or*/ ['clienta', 'clientb', 'clientc' ...] /*or * if none specified */,
    'action': 'exec:./doSomethingElse'
   }
 }
}

//the plugin

module.exports = function Plugin (pluginSpec) {
   this.plugin = {};
   this.plugin.triggers = {};
   Object.keys(pluginSpec).spec.forEach(function(key) {
    var clients = pluginSpec.spec[key].clients;
    plugin.triggers[key].clients = {};
    
    if(Array.isArray(clients)) {
      clients.forEach(function(client) {
        plugin.triggers[key].clients[client] = pluginSpec.spec[key].action;
      });
   } else if (clients === undefined || clients === '*') {
     plugin.triggers[key].clients['*'] = pluginSpec.spec[key].action;
   } else if(typeof clients === 'string') {
    plugin.triggers[key].clients[clients] = pluginSpec[key].action;
   } 
 });
}
 
Plugin.prototype.run = function(trigger, client, context) {
  if (this.plugin.triggers[trigger] && this.plugin.triggers[trigger].clients[client]) {
    this.plugin.triggers[trigger].clients[client].apply(null, arguments);
  }
}

//the registry

var Registry = function() {
  this.plugins = {}; 
}

Registry.prototype.add = function(pluginSpec) {
     Assert.ok(Thing.isString(pluginSpec.name), 'Expected name to be a string.');
     Plugins[pluginSpec.name] = new Plugins(pluginSpec);
     
}
    
Registry.prototype.remove = function(plugin /*name or spec*/) {
    if (typeof plugin !== 'string') {
      plugin = plugin.name;
    }
    delete plugins[plugin];
  } 
};
    
Registry.prototype.run = function(trigger, client, context) {
  var args = Array.prototype.slice.call(arguments);
  this.plugins.forEach(function(p) {
     p.run.apply(null, args);
  });
}


//usage of registry

servicore.plugins = new Registry();
servicecore.plugins.add(pluginSpec); //can be stashed into a json file the plugin modules

//to run them.

servicecore.plugins.run('onTransport', 'clientName', options);