services/lib/servicetracker.js

A Service layer for node js.

"use strict"; 
// External
var _ = require("underscore");

// inernal
var check = require("./exceptions").create("serviceTracker");

module.exports = function(service, binder) {
	check.notNull(service, "service");
	check.notNull(binder, "binder");

	var handler = function(otherService) {
		if(otherService !== service) {
			binder.bind(otherService);
		}
	};

	var stopHandler = function(otherService) {
		if(otherService !== service) {
			binder.unbind(otherService);
		}
	};

	var started  = false;

	this.start = function(context) {
		if(!started) {
			started = true;
			_.each(service.consumes(), function(e) {
				context.findServices(e.serviceClass, handler);
			});

			context.on("serviceStarted", handler);
			context.on("serviceStopped", stopHandler);
		}
	};

	this.stop = function(context) {
		if(started) {
			context.removeListener("serviceStarted", handler);
			context.removeListener("serviceStopped", stopHandler);
		}
	};
};