shelloid/src/lib/extmgr.js

Open source IoT-ready real-time big data web application platform that integrates Node.js and Clojure.

/*
 Copyright (c) Shelloid Systems LLP. All rights reserved.
 The use and distribution terms for this software are covered by the
 GNU Lesser General Public License 3.0 (https://www.gnu.org/licenses/lgpl.html)
 which can be found in the file LICENSE at the root of this distribution.
 By using this software in any fashion, you are agreeing to be bound by
 the terms of this license.
 You must not remove this notice, or any other, from this software.
 */

var path = require("path");
var fs = require("fs");
var utils = lib_require("utils");
 
exports.loadExtensions = function(done){	
	sh.ext = {hooks:{}, annotationProcessors:{}, mods:[]};

	var internalBuiltInsDir = path.join(sh.serverCtx.basePath, sh.appCtx.config.dirs._ext);
	loadBuiltins(
		internalBuiltInsDir, 
		"internal",
		loadExternal.bind(
			null, 
			loadBuiltins.bind(null, sh.appCtx.config.dirs.ext, "app", done)
		)
	);
}

function loadBuiltins(extDir, kind, done){
	if(!utils.dirExists(extDir)){
		done();
		return;
	}
	
	var files = fs.readdirSync(extDir);
	for(var i=0;i<files.length;i++){
		var p = path.resolve(extDir, files[i]);
		if(utils.dirExists(p)){
			p = path.resolve(p, "index.js");
		}
		if(utils.fileExists(p)){
			var ext = require(p);
			sh.info("Processing extension: " + p);
			var extInfo = ext();
			extInfo.path = p;
			extInfo.name = files[i];
			extInfo.kind = kind;
			addExtension(extInfo);
		}
	}
	done();
}

function loadExternal(done){
	var exts = sh.appCtx.config.extensions;
	var barrier = utils.countingBarrier(exts.length, done);
	for(var i=0;i<exts.length;i++){
		(function(ext){
			app_pkg.require(ext.name, ext.version,
				function(mod){
					extInfo = mod();
					extInfo.kind  = "external";
					extInfo.name = ext.name;
					extInfo.version = ext.version;
					addExtension(extInfo);
					barrier.countDown();
				}
			);
		})(exts[i]);
	}	
}

function addExtension(extInfo){
	sh.ext.mods.push(extInfo);
	if(extInfo.annotations){
		for(var i=0;i<extInfo.annotations.length;i++){
			var annotationDef = extInfo.annotations[i];
			sh.ext.annotationProcessors[annotationDef.name] = annotationDef;
		}
	}
	
	if(extInfo.hooks){
		for(var i=0;i<extInfo.hooks.length;i++){
			var hook = extInfo.hooks[i];
			if(!hook.priority && hook.priority != 0){
				hook.priority = Infinity;
			}
			if(!sh.ext.hooks[hook.type]){
				sh.ext.hooks[hook.type] = [];
			}
			utils.priorityInsert(sh.ext.hooks[hook.type], hook);
		}
	}

	if(extInfo.services){
		for(var k1 in extInfo.services){
			//TODO check for conflicts.
			var svc = extInfo.services[k1];
			if(!sh.services[k1]){
				sh.services[k1] = {};
			}
			for(var k2 in svc){
				var svcEntry = svc[k2];
				if(utils.isObject(svcEntry)){//sub-services
					if(!sh.services[k1][k2]){
						sh.services[k1][k2] = {};
					}
					for(var k3 in svcEntry){
						sh.services[k1][k2][k3] = svcEntry[k3];
					}
				}else{
					sh.services[k1][k2] = svcEntry;
				}
			}
		}
	}	
}

exports.addHook = function(hookType, hookInfo){
	if(!sh.ext.hooks[hookType]){
		sh.ext.hooks[hookType] = [];
	}
	utils.priorityInsert(sh.ext.hooks[hookType], hookInfo);
}